Sonia Bahroo, PA-C

One of the most common complications of pregnancy is gestational diabetes mellitus (GDM). It is defined as glucose intolerance with first onset during pregnancy.¹ In 2011, the incidence of GDM in the United States was between 2% and 10% of all pregnancies. Potential complications associated with GDM include macrosomia, pre-eclampsia, preterm birth, increased risk for cesarean section, neonatal hypoglycemia, shoulder dystocia, and polyhydramnios. Women with a history of gestational diabetes have a 35% to 60% likelihood of developing type 2 diabetes over the following 10 to 20 years.²

Q: When should screening for GDM occur?

According to the American Diabetes Association’s (ADA) 2012 Clinical Practice Recommendations, a pregnant woman should be screened for undiagnosed type 2 diabetes at her first prenatal visit if she has certain risk factors.³ These include, but are not limited to, family history of diabetes, overweight/obesity, sedentary life­style, elevated blood pressure and/or cholesterol, impaired fasting glucose or impaired glucose tolerance, or certain ethnic backgrounds (eg, Hispanic, Native American, and non-Hispanic black).⁴ In 2011, the ADA revised its recommendations for GDM screening and diagnosis to be in accordance with those from the International Association of Diabetes and Pregnancy Study Groups (IADPSG), an interna­tional consensus group with representatives from multiple obstetric and diabetes organizations, including ADA.

Q: How is GDM diagnosed?

Current recommendations stipulate that women with no previous history of diabetes or prediabetes undergo one-step testing: a 75-g glucose tolerance test (GTT) at 24 to 28 weeks’ gestation.^5,6 For women with a prior history of GDM, screening is recommended earlier in the pregnancy. The GTT should be performed after an overnight fast of at least eight hours.³ An elevation of any one of the values above normal reference range is consistent with the diagnosis of GDM. (Previously, the diagnostic criteria required two abnormal values.) Multiple international studies using the new criteria have estimated an increased incidence of gestational diabetes in up to 18% of pregnancies.^5,6

Some organizations have not endorsed the IADPSG/ADA diagnostic criteria at this time; as a result, many practitioners continue to use two-step testing for diagnosing GDM. To do the two-step testing, a 50-g glucose load is given, followed by a blood glucose reading one hour later. If the one-hour reading is within normal range, no further testing is warranted and the patient does not have gestational diabetes. If the test is abnormal, she must undergo a fasting three-hour GTT using a 100-g glucose load.

Q: What advice should a woman get once she’s diagnosed with GDM? 

As soon as a woman is diagnosed with GDM, she should be referred for a gestational diabetes education class and nutrition counseling. Specifically, she should learn what it means for her to have GDM, implications for her and her baby, and the importance of eating a healthy diet (not the proverbial concept of “eating for two”), physical activity, self-monitoring blood glucose, and adherence to any prescribed medications.

Probably the most important aspect of education is nutrition counseling. It is known that smaller meals consumed more frequently throughout the day reduce spikes in blood glucose levels. One suggestion is to eat three small meals and three low-carbohydrate (15 g) snacks each day. Meals and snacks are generally established based on fixed carbohydrate amounts. A certified diabetes educator or registered dietitian (RD) can recommend healthy meal and snack ideas that are tasty, promote satiety, and minimize spikes in glucose levels.

Q: What are the current treatment options for GDM?

During the process of receiving GDM education, the patient should be prescribed a glucometer, along with specific glucose targets. Blood glucose should be checked multiple times a day, preferably fasting and postprandial measurements. Medical practices vary in their preferred glucose targets; some individuals require tighter control than others. The ADA suggests the following targets:

• Before a meal (preprandial):
95 mg/dL or less.

 • One hour after a meal (postprandial): 140 mg/dL or less.

• Two hours after a meal (postprandial): 120 mg/dL or less. ⁷ 

If blood glucose levels remain within normal range, it is possible to control gestational diabetes with dietary modification and physical activity. If readings are consistently elevated, then the patient must be started on medication. There are currently no FDA-approved oral medications to treat gestational diabetes. Glyburide is commonly used, although it is not FDA approved for this indication. More studies to establish its safety are likely needed for FDA approval.⁸

If pharmaceutical treatment is warranted, insulin is the safest and most effective agent. It is the only medication that is FDA approved for treatment of GDM.  Levemir (insulin detemir [rDNA origin] injection) gained FDA approval for use in pregnancy in 2012, so it has become more widespread than NPH for basal insulin usage.⁹

Although it is usually managed by an endocrinologist or perinatologist, an experienced obstetrician could also manage GDM. Often, the patient is referred to an endocrinologist. The endocrine provider, along with the diabetes educator and RD, focus on nutrition counseling and diabetes management so the obstetrician can focus on maternal and fetal health. 

Q: What is the recommended follow-up?

Since embryonic and fetal development occurs at such a rapid rate, time is of the essence for getting a patient’s blood glucose to goal. While treating diabetes in general can be challenging, this is usually not the case with GDM. Most women with GDM are motivated to take care of themselves for the well-being of their developing baby. The influence of a baby developing inside a mother is so strong that diabetic women who become pregnant often take better care of themselves than they do when they are not pregnant.

The patient’s daily responsibilities should include eating a healthy and diet checking her blood glucose levels throughout the day. These readings must be recorded. Clinic visits should occur often, with emailing of glucose readings between visits as needed. The frequency of visits varies among practices, depending on the patient’s level of glucose control and intensity of the treatment regimen.

Q: Why is postpartum testing important?

After delivery, most cases of GDM usually resolve. However, approximately 5% to 10% of women with gestational diabetes are found to have diabetes immediately after pregnancy.² To evaluate for persistent diabetes, a two-hour GTT should be done at six weeks’ postpartum. Although an A1C can now be used to diagnose diabetes, the ADA does not recommend checking it for this purpose.³

If the two-hour GTT result is normal, a woman should be screened for diabetes every three years for the rest of her life.³ If a diagnosis of impaired fasting glucose or impaired glucose tolerance is made, then she should be tested for diabetes on an annual basis or in the interim if she develops classic symptoms of hyperglycemia.³ If diabetes is diagnosed, she should be treated accordingly as a type 2 diabetic patient.

At this time, the patient should be counseled on lifestyle interventions and consider starting metformin therapy if appropriate. Diabetes education classes are available for prediabetes. To maintain good health and prevent/delay onset of type 2 diabetes, here are some tips to follow: 

 • The same diet as during pregnancy does not have to be followed, although healthy eating habits are always a good idea.

• Physical activity (approximately 30 min five times a week) will help shed weight gained during pregnancy.

• Breastfeeding promotes weight loss.¹⁰

• Patients should aim for weight loss of 7% of body weight.³

• Continue annual physical exams, keeping an eye on blood pressure, weight, and cholesterol levels.

It’s reasonable for the patient to check glucose levels occasionally after delivery. If elevated readings occur, the patient can make an appointment with her primary care provider or endocrinologist.

References
1.  American Association for Clinical Chemistry. A New Definition of Gestational Diabetes. www.aacc.org/publications/cln/2010/may/Pages/CoverStory2May2010.aspx. Accessed June 30, 2013.

2. National Diabetes Statistics, 2011. www.diabetes.niddk.nih.gov/dm/pubs/statistics/#Gestational. Accessed July 22, 2013.

3. American Diabetes Association. 2012 Clinical Practice Recommendations. Diabetes Care. 2012;35(suppl 1). http://professional.diabetes.org/SlideLibrary/media/4839/ADA%20Standards%20of%20Medical%20Care%202012%20FINAL.ppt. Accessed June 24, 2013.

4. American Diabetes Association. Diabetes basics: your risk. www.diabetes.org/diabetes-basics/prevention/risk-factors. Accessed August 13, 2013.

5. American Diabetes Association. Diabetes Basics: What is Gestational Diabetes? www.diabetes.org/diabetes-basics/gestational/what-is-gestational-diabetes.html. Accessed August 13, 2013.

 6. Johnson K. New criteria for gestational diabetes increase diagnoses (December 5, 2011). www.medscape.com/viewarticle/754733. Accessed August 13, 2013.

 7. American Diabetes Association. Diabetes basics: how to treat gestational diabetes. www.diabetes.org/diabetes-basics/gestational/how-to-treat-gestational.html. Accessed August 13, 2013.

8. Moore TR. Glyburide for the treatment of gestational diabetes: a critical appraisal. Diabetes Care. 2007;30(suppl 2). http://care.diabetesjournals.org/content/30/Supplement_2/S209.full. Accessed August 13, 2013.

9. Lowes R. Levemir assigned more reassuring pregnancy risk category (April 2, 2012). www.medscape.com/viewarticle/761349. Accessed August 13, 2013.

10. Buchanan TA, Xiang AH, Page KA. Gestational diabetes mellitus: risks and management during and after pregnancy. Nat Rev Endocrinol. 2012;8(11):639-649.

One of the most common complications of pregnancy is gestational diabetes mellitus (GDM). It is defined as glucose intolerance with first onset during pregnancy.¹ In 2011, the incidence of GDM in the United States was between 2% and 10% of all pregnancies. Potential complications associated with GDM include macrosomia, pre-eclampsia, preterm birth, increased risk for cesarean section, neonatal hypoglycemia, shoulder dystocia, and polyhydramnios. Women with a history of gestational diabetes have a 35% to 60% likelihood of developing type 2 diabetes over the following 10 to 20 years.²

Q: When should screening for GDM occur?

According to the American Diabetes Association’s (ADA) 2012 Clinical Practice Recommendations, a pregnant woman should be screened for undiagnosed type 2 diabetes at her first prenatal visit if she has certain risk factors.³ These include, but are not limited to, family history of diabetes, overweight/obesity, sedentary life­style, elevated blood pressure and/or cholesterol, impaired fasting glucose or impaired glucose tolerance, or certain ethnic backgrounds (eg, Hispanic, Native American, and non-Hispanic black).⁴ In 2011, the ADA revised its recommendations for GDM screening and diagnosis to be in accordance with those from the International Association of Diabetes and Pregnancy Study Groups (IADPSG), an interna­tional consensus group with representatives from multiple obstetric and diabetes organizations, including ADA.

Q: How is GDM diagnosed?

Current recommendations stipulate that women with no previous history of diabetes or prediabetes undergo one-step testing: a 75-g glucose tolerance test (GTT) at 24 to 28 weeks’ gestation.^5,6 For women with a prior history of GDM, screening is recommended earlier in the pregnancy. The GTT should be performed after an overnight fast of at least eight hours.³ An elevation of any one of the values above normal reference range is consistent with the diagnosis of GDM. (Previously, the diagnostic criteria required two abnormal values.) Multiple international studies using the new criteria have estimated an increased incidence of gestational diabetes in up to 18% of pregnancies.^5,6

Some organizations have not endorsed the IADPSG/ADA diagnostic criteria at this time; as a result, many practitioners continue to use two-step testing for diagnosing GDM. To do the two-step testing, a 50-g glucose load is given, followed by a blood glucose reading one hour later. If the one-hour reading is within normal range, no further testing is warranted and the patient does not have gestational diabetes. If the test is abnormal, she must undergo a fasting three-hour GTT using a 100-g glucose load.

Q: What advice should a woman get once she’s diagnosed with GDM? 

As soon as a woman is diagnosed with GDM, she should be referred for a gestational diabetes education class and nutrition counseling. Specifically, she should learn what it means for her to have GDM, implications for her and her baby, and the importance of eating a healthy diet (not the proverbial concept of “eating for two”), physical activity, self-monitoring blood glucose, and adherence to any prescribed medications.

Probably the most important aspect of education is nutrition counseling. It is known that smaller meals consumed more frequently throughout the day reduce spikes in blood glucose levels. One suggestion is to eat three small meals and three low-carbohydrate (15 g) snacks each day. Meals and snacks are generally established based on fixed carbohydrate amounts. A certified diabetes educator or registered dietitian (RD) can recommend healthy meal and snack ideas that are tasty, promote satiety, and minimize spikes in glucose levels.

Q: What are the current treatment options for GDM?

During the process of receiving GDM education, the patient should be prescribed a glucometer, along with specific glucose targets. Blood glucose should be checked multiple times a day, preferably fasting and postprandial measurements. Medical practices vary in their preferred glucose targets; some individuals require tighter control than others. The ADA suggests the following targets:

• Before a meal (preprandial):
95 mg/dL or less.

 • One hour after a meal (postprandial): 140 mg/dL or less.

• Two hours after a meal (postprandial): 120 mg/dL or less. ⁷ 

If blood glucose levels remain within normal range, it is possible to control gestational diabetes with dietary modification and physical activity. If readings are consistently elevated, then the patient must be started on medication. There are currently no FDA-approved oral medications to treat gestational diabetes. Glyburide is commonly used, although it is not FDA approved for this indication. More studies to establish its safety are likely needed for FDA approval.⁸

If pharmaceutical treatment is warranted, insulin is the safest and most effective agent. It is the only medication that is FDA approved for treatment of GDM.  Levemir (insulin detemir [rDNA origin] injection) gained FDA approval for use in pregnancy in 2012, so it has become more widespread than NPH for basal insulin usage.⁹

Although it is usually managed by an endocrinologist or perinatologist, an experienced obstetrician could also manage GDM. Often, the patient is referred to an endocrinologist. The endocrine provider, along with the diabetes educator and RD, focus on nutrition counseling and diabetes management so the obstetrician can focus on maternal and fetal health. 

Q: What is the recommended follow-up?

Since embryonic and fetal development occurs at such a rapid rate, time is of the essence for getting a patient’s blood glucose to goal. While treating diabetes in general can be challenging, this is usually not the case with GDM. Most women with GDM are motivated to take care of themselves for the well-being of their developing baby. The influence of a baby developing inside a mother is so strong that diabetic women who become pregnant often take better care of themselves than they do when they are not pregnant.

The patient’s daily responsibilities should include eating a healthy and diet checking her blood glucose levels throughout the day. These readings must be recorded. Clinic visits should occur often, with emailing of glucose readings between visits as needed. The frequency of visits varies among practices, depending on the patient’s level of glucose control and intensity of the treatment regimen.

Q: Why is postpartum testing important?

After delivery, most cases of GDM usually resolve. However, approximately 5% to 10% of women with gestational diabetes are found to have diabetes immediately after pregnancy.² To evaluate for persistent diabetes, a two-hour GTT should be done at six weeks’ postpartum. Although an A1C can now be used to diagnose diabetes, the ADA does not recommend checking it for this purpose.³

If the two-hour GTT result is normal, a woman should be screened for diabetes every three years for the rest of her life.³ If a diagnosis of impaired fasting glucose or impaired glucose tolerance is made, then she should be tested for diabetes on an annual basis or in the interim if she develops classic symptoms of hyperglycemia.³ If diabetes is diagnosed, she should be treated accordingly as a type 2 diabetic patient.

At this time, the patient should be counseled on lifestyle interventions and consider starting metformin therapy if appropriate. Diabetes education classes are available for prediabetes. To maintain good health and prevent/delay onset of type 2 diabetes, here are some tips to follow: 

 • The same diet as during pregnancy does not have to be followed, although healthy eating habits are always a good idea.

• Physical activity (approximately 30 min five times a week) will help shed weight gained during pregnancy.

• Breastfeeding promotes weight loss.¹⁰

• Patients should aim for weight loss of 7% of body weight.³

• Continue annual physical exams, keeping an eye on blood pressure, weight, and cholesterol levels.

It’s reasonable for the patient to check glucose levels occasionally after delivery. If elevated readings occur, the patient can make an appointment with her primary care provider or endocrinologist.

References
1.  American Association for Clinical Chemistry. A New Definition of Gestational Diabetes. www.aacc.org/publications/cln/2010/may/Pages/CoverStory2May2010.aspx. Accessed June 30, 2013.

2. National Diabetes Statistics, 2011. www.diabetes.niddk.nih.gov/dm/pubs/statistics/#Gestational. Accessed July 22, 2013.

3. American Diabetes Association. 2012 Clinical Practice Recommendations. Diabetes Care. 2012;35(suppl 1). http://professional.diabetes.org/SlideLibrary/media/4839/ADA%20Standards%20of%20Medical%20Care%202012%20FINAL.ppt. Accessed June 24, 2013.

4. American Diabetes Association. Diabetes basics: your risk. www.diabetes.org/diabetes-basics/prevention/risk-factors. Accessed August 13, 2013.

5. American Diabetes Association. Diabetes Basics: What is Gestational Diabetes? www.diabetes.org/diabetes-basics/gestational/what-is-gestational-diabetes.html. Accessed August 13, 2013.

 6. Johnson K. New criteria for gestational diabetes increase diagnoses (December 5, 2011). www.medscape.com/viewarticle/754733. Accessed August 13, 2013.

 7. American Diabetes Association. Diabetes basics: how to treat gestational diabetes. www.diabetes.org/diabetes-basics/gestational/how-to-treat-gestational.html. Accessed August 13, 2013.

8. Moore TR. Glyburide for the treatment of gestational diabetes: a critical appraisal. Diabetes Care. 2007;30(suppl 2). http://care.diabetesjournals.org/content/30/Supplement_2/S209.full. Accessed August 13, 2013.

9. Lowes R. Levemir assigned more reassuring pregnancy risk category (April 2, 2012). www.medscape.com/viewarticle/761349. Accessed August 13, 2013.

10. Buchanan TA, Xiang AH, Page KA. Gestational diabetes mellitus: risks and management during and after pregnancy. Nat Rev Endocrinol. 2012;8(11):639-649.

One of the most common complications of pregnancy is gestational diabetes mellitus (GDM). It is defined as glucose intolerance with first onset during pregnancy.¹ In 2011, the incidence of GDM in the United States was between 2% and 10% of all pregnancies. Potential complications associated with GDM include macrosomia, pre-eclampsia, preterm birth, increased risk for cesarean section, neonatal hypoglycemia, shoulder dystocia, and polyhydramnios. Women with a history of gestational diabetes have a 35% to 60% likelihood of developing type 2 diabetes over the following 10 to 20 years.²

Q: When should screening for GDM occur?

According to the American Diabetes Association’s (ADA) 2012 Clinical Practice Recommendations, a pregnant woman should be screened for undiagnosed type 2 diabetes at her first prenatal visit if she has certain risk factors.³ These include, but are not limited to, family history of diabetes, overweight/obesity, sedentary life­style, elevated blood pressure and/or cholesterol, impaired fasting glucose or impaired glucose tolerance, or certain ethnic backgrounds (eg, Hispanic, Native American, and non-Hispanic black).⁴ In 2011, the ADA revised its recommendations for GDM screening and diagnosis to be in accordance with those from the International Association of Diabetes and Pregnancy Study Groups (IADPSG), an interna­tional consensus group with representatives from multiple obstetric and diabetes organizations, including ADA.

Q: How is GDM diagnosed?

Current recommendations stipulate that women with no previous history of diabetes or prediabetes undergo one-step testing: a 75-g glucose tolerance test (GTT) at 24 to 28 weeks’ gestation.^5,6 For women with a prior history of GDM, screening is recommended earlier in the pregnancy. The GTT should be performed after an overnight fast of at least eight hours.³ An elevation of any one of the values above normal reference range is consistent with the diagnosis of GDM. (Previously, the diagnostic criteria required two abnormal values.) Multiple international studies using the new criteria have estimated an increased incidence of gestational diabetes in up to 18% of pregnancies.^5,6

Some organizations have not endorsed the IADPSG/ADA diagnostic criteria at this time; as a result, many practitioners continue to use two-step testing for diagnosing GDM. To do the two-step testing, a 50-g glucose load is given, followed by a blood glucose reading one hour later. If the one-hour reading is within normal range, no further testing is warranted and the patient does not have gestational diabetes. If the test is abnormal, she must undergo a fasting three-hour GTT using a 100-g glucose load.

Q: What advice should a woman get once she’s diagnosed with GDM? 

As soon as a woman is diagnosed with GDM, she should be referred for a gestational diabetes education class and nutrition counseling. Specifically, she should learn what it means for her to have GDM, implications for her and her baby, and the importance of eating a healthy diet (not the proverbial concept of “eating for two”), physical activity, self-monitoring blood glucose, and adherence to any prescribed medications.

Probably the most important aspect of education is nutrition counseling. It is known that smaller meals consumed more frequently throughout the day reduce spikes in blood glucose levels. One suggestion is to eat three small meals and three low-carbohydrate (15 g) snacks each day. Meals and snacks are generally established based on fixed carbohydrate amounts. A certified diabetes educator or registered dietitian (RD) can recommend healthy meal and snack ideas that are tasty, promote satiety, and minimize spikes in glucose levels.

Q: What are the current treatment options for GDM?

During the process of receiving GDM education, the patient should be prescribed a glucometer, along with specific glucose targets. Blood glucose should be checked multiple times a day, preferably fasting and postprandial measurements. Medical practices vary in their preferred glucose targets; some individuals require tighter control than others. The ADA suggests the following targets:

• Before a meal (preprandial):
95 mg/dL or less.

 • One hour after a meal (postprandial): 140 mg/dL or less.

• Two hours after a meal (postprandial): 120 mg/dL or less. ⁷ 

If blood glucose levels remain within normal range, it is possible to control gestational diabetes with dietary modification and physical activity. If readings are consistently elevated, then the patient must be started on medication. There are currently no FDA-approved oral medications to treat gestational diabetes. Glyburide is commonly used, although it is not FDA approved for this indication. More studies to establish its safety are likely needed for FDA approval.⁸

If pharmaceutical treatment is warranted, insulin is the safest and most effective agent. It is the only medication that is FDA approved for treatment of GDM.  Levemir (insulin detemir [rDNA origin] injection) gained FDA approval for use in pregnancy in 2012, so it has become more widespread than NPH for basal insulin usage.⁹

Although it is usually managed by an endocrinologist or perinatologist, an experienced obstetrician could also manage GDM. Often, the patient is referred to an endocrinologist. The endocrine provider, along with the diabetes educator and RD, focus on nutrition counseling and diabetes management so the obstetrician can focus on maternal and fetal health. 

Q: What is the recommended follow-up?

Since embryonic and fetal development occurs at such a rapid rate, time is of the essence for getting a patient’s blood glucose to goal. While treating diabetes in general can be challenging, this is usually not the case with GDM. Most women with GDM are motivated to take care of themselves for the well-being of their developing baby. The influence of a baby developing inside a mother is so strong that diabetic women who become pregnant often take better care of themselves than they do when they are not pregnant.

The patient’s daily responsibilities should include eating a healthy and diet checking her blood glucose levels throughout the day. These readings must be recorded. Clinic visits should occur often, with emailing of glucose readings between visits as needed. The frequency of visits varies among practices, depending on the patient’s level of glucose control and intensity of the treatment regimen.

Q: Why is postpartum testing important?

After delivery, most cases of GDM usually resolve. However, approximately 5% to 10% of women with gestational diabetes are found to have diabetes immediately after pregnancy.² To evaluate for persistent diabetes, a two-hour GTT should be done at six weeks’ postpartum. Although an A1C can now be used to diagnose diabetes, the ADA does not recommend checking it for this purpose.³

If the two-hour GTT result is normal, a woman should be screened for diabetes every three years for the rest of her life.³ If a diagnosis of impaired fasting glucose or impaired glucose tolerance is made, then she should be tested for diabetes on an annual basis or in the interim if she develops classic symptoms of hyperglycemia.³ If diabetes is diagnosed, she should be treated accordingly as a type 2 diabetic patient.

At this time, the patient should be counseled on lifestyle interventions and consider starting metformin therapy if appropriate. Diabetes education classes are available for prediabetes. To maintain good health and prevent/delay onset of type 2 diabetes, here are some tips to follow: 

 • The same diet as during pregnancy does not have to be followed, although healthy eating habits are always a good idea.

• Physical activity (approximately 30 min five times a week) will help shed weight gained during pregnancy.

• Breastfeeding promotes weight loss.¹⁰

• Patients should aim for weight loss of 7% of body weight.³

• Continue annual physical exams, keeping an eye on blood pressure, weight, and cholesterol levels.

It’s reasonable for the patient to check glucose levels occasionally after delivery. If elevated readings occur, the patient can make an appointment with her primary care provider or endocrinologist.

References
1.  American Association for Clinical Chemistry. A New Definition of Gestational Diabetes. www.aacc.org/publications/cln/2010/may/Pages/CoverStory2May2010.aspx. Accessed June 30, 2013.

2. National Diabetes Statistics, 2011. www.diabetes.niddk.nih.gov/dm/pubs/statistics/#Gestational. Accessed July 22, 2013.

3. American Diabetes Association. 2012 Clinical Practice Recommendations. Diabetes Care. 2012;35(suppl 1). http://professional.diabetes.org/SlideLibrary/media/4839/ADA%20Standards%20of%20Medical%20Care%202012%20FINAL.ppt. Accessed June 24, 2013.

4. American Diabetes Association. Diabetes basics: your risk. www.diabetes.org/diabetes-basics/prevention/risk-factors. Accessed August 13, 2013.

5. American Diabetes Association. Diabetes Basics: What is Gestational Diabetes? www.diabetes.org/diabetes-basics/gestational/what-is-gestational-diabetes.html. Accessed August 13, 2013.

 6. Johnson K. New criteria for gestational diabetes increase diagnoses (December 5, 2011). www.medscape.com/viewarticle/754733. Accessed August 13, 2013.

 7. American Diabetes Association. Diabetes basics: how to treat gestational diabetes. www.diabetes.org/diabetes-basics/gestational/how-to-treat-gestational.html. Accessed August 13, 2013.

8. Moore TR. Glyburide for the treatment of gestational diabetes: a critical appraisal. Diabetes Care. 2007;30(suppl 2). http://care.diabetesjournals.org/content/30/Supplement_2/S209.full. Accessed August 13, 2013.

9. Lowes R. Levemir assigned more reassuring pregnancy risk category (April 2, 2012). www.medscape.com/viewarticle/761349. Accessed August 13, 2013.

10. Buchanan TA, Xiang AH, Page KA. Gestational diabetes mellitus: risks and management during and after pregnancy. Nat Rev Endocrinol. 2012;8(11):639-649.

A 42-year-old obese woman with type 2 diabetes, diabetic retinopathy, hyper­tension, and hirsutism presents to discuss an elevated prolactin level of 144.8 ng/mL (normal range, 4.8 to 23.3 ng/mL) found by her Ob-Gyn two months ago. She complained of galactorrhea and no menses for one year. A repeat prolactin level was also elevated, at 109 ng/mL.

A pituitary MRI with contrast showed a “subtle area of delayed enhancement in the right pituitary, consistent with a 5-mm microadenoma.” The patient was prescribed the dopamine agonist cabergoline (0.25 mg, to be taken twice a week), with a plan to follow up in two to three months.

Q: In obtaining a thorough history, what additional questions should be asked of this patient?

There are many causes of hyperprolactinemia. Factors that can increase prolactin secretion include pregnancy, nursing, physiologic stress, estrogen use, polycystic ovary syndrome, hypothyroidism, and chronic renal or hepatic failure. Head trauma, use of certain medications (verapamil, neuroleptics, antipsychotics, and antidepressants), and presence of nonsecretory sellar or suprasellar masses can also increase prolactin levels. 

In general, signs and symptoms are due to either the effect of excess hormone secretion (ie, galactorrhea and amenorrhea) or local compression (ie, new-onset or persistent headache, dizziness, visual changes, and vision loss). A review of medications, including estrogen therapy, and history of fertility or gonadal dysfunction should be documented. Elevated prolactin levels can result in secondary hypogonadism.¹

Note: While the case patient is female, it should be emphasized that prolactinomas do occur in men. The incidence is, overall, low. In addition to the symptoms listed above, men can present with decreased libido and infertility.¹

Q: What additional diagnostic tests should be ordered as part of the work-up of galactorrhea and amenorrhea in this patient?

Laboratory evaluation should include a repeat serum prolactin test, measurements of TSH and free T4, and a pregnancy test. (A serum testosterone level should be checked in men.) If the results come back normal and if other diagnoses are excluded, the most likely diagnosis is a prolactinoma. In this case, a pituitary MRI should be obtained. Visual field testing can be performed in individuals with specific visual complaints, especially loss or impairment of peripheral vision.

Q: What is the incidence of prolactinoma in the general population?

Prolactin-secreting adenomas, or prolactinomas, are the most common type of pituitary adenoma, accounting for approximately 60% overall.¹ They occur at a frequency of six to 10 cases per million each year.² Prolactinomas are almost always benign; malignant tumors are extremely rare.³

Tumors are classified as microadenomas or macroadenomas, depending on the size. A microadenoma is defined as an intrasellar mass less than 10 mm in diameter. A macroadenoma, defined as larger than 10 mm in diameter, can cause enlargement of the sella turcica.^1,4 The larger the size of the prolactinoma, the greater the prolactin level and higher the likelihood of mass-effect symptoms.⁴

Q: What are the options for treatment of a prolactinoma?

There are several options for treatment of prolactinomas. After discussing all of the available options with the patient, the choice of therapy should be determined by the patient’s desires and potential plans for pregnancy. It is acceptable to observe the tumor with serial MRIs and serum prolactin measurements, provided the tumor is very small and the patient is asymptomatic.⁴

Medication therapy involves treatment with a dopamine agonist, which directly inhibits prolactin secretion by the tumor and therefore suppresses tumor growth. The goal of medication therapy is to suppress the prolactin level to normal range and restore gonadal function. The two dopamine agonists used are bromocriptine and cabergoline. 

Bromocriptine was the first drug available in the United States to effectively treat pituitary adenomas. Its most common adverse effects include nausea, vomiting, dizziness, and postural hypotension. These effects can be minimized or avoided if the drug is started at a low dose, gradually increased, and taken at bedtime. The adverse effects usually subside with continued use; however, in some patients they persist and therefore the drug has to be discontinued.

Cabergoline is a non-ergot dopamine agonist that is more efficacious, overall better tolerated, and longer acting than bromocriptine. It is dosed twice weekly, whereas bromocriptine is dosed once daily.⁴ One factor to consider in a female patient is whether she is of child-bearing age and is interested in conception. Both bromocriptine and cabergoline are designated as category B; however, in animal studies cabergoline has been associated with maternal toxicity, increase in fetal death, and growth retardation and death due to decreased milk secretion by the mother. Therefore, it should only be used during pregnancy if the need has been clearly established.

Dopamine agonists are approximately 80% to 90% effective in decreasing prolactin levels and reducing tumor size in microadenomas and 60% to 70% in macroadenomas. The major drawback of using medication is that it does not always provide permanent results. Hyperprolactinemia and tumor growth can resume upon discontinuation of the drug, even if the patient has taken it for several years.¹ The rate of recurrence after discontinuing therapy can be anywhere from 26% to 69%, and the highest likelihood occurs within a year of withdrawal.⁴ Close clinical follow-up is thus important.

Surgery, typically a transphenoidal resection, is performed by a neurosurgeon. Success of surgery is based on tumor size and basal prolactin level prior to the procedure. It is more effective in restoring normal prolactin levels and resolution of symptoms in microadenomas than in macroadenomas. Progressive vision loss, pituitary apoplexy, and intolerance to dopamine agonists are indications for surgery.¹

Radiation therapy is reserved for those patients who have residual tumors postsurgery and have not responded to or are intolerant to dopamine agonists. Response to radiation is slow; it can sometimes take several years to achieve full effect. Gamma-knife radiation is sometimes used, but experience with this procedure is limited thus far in prolactinomas.

Overall, the vast majority of prolactinomas are benign and fairly straightforward to manage clinically.³           

REFERENCES
1. Greenspan F, Gardner D. Basic & Clinical Endocrinology, 7th ed. New York: McGraw-Hill; 2004.

2. Ciccarelli A, Daly A, Beckers A. The epidemiology of prolactinomas. Pituitary. 2005;8(1):3-6.

3. Casanueva FF, Molitch ME, Schlechte JA, et al. Guidelines of the Pituitary Society for the diagnosis and management of prolactinomas. Clin Endocrinol (Oxf). 2006;65(2):265-273.

4. Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society Clinical Practice Guideline. J Clinical Endocrinol Metab. 2011;96(2):273-288.

A 42-year-old obese woman with type 2 diabetes, diabetic retinopathy, hyper­tension, and hirsutism presents to discuss an elevated prolactin level of 144.8 ng/mL (normal range, 4.8 to 23.3 ng/mL) found by her Ob-Gyn two months ago. She complained of galactorrhea and no menses for one year. A repeat prolactin level was also elevated, at 109 ng/mL.

A pituitary MRI with contrast showed a “subtle area of delayed enhancement in the right pituitary, consistent with a 5-mm microadenoma.” The patient was prescribed the dopamine agonist cabergoline (0.25 mg, to be taken twice a week), with a plan to follow up in two to three months.

Q: In obtaining a thorough history, what additional questions should be asked of this patient?

There are many causes of hyperprolactinemia. Factors that can increase prolactin secretion include pregnancy, nursing, physiologic stress, estrogen use, polycystic ovary syndrome, hypothyroidism, and chronic renal or hepatic failure. Head trauma, use of certain medications (verapamil, neuroleptics, antipsychotics, and antidepressants), and presence of nonsecretory sellar or suprasellar masses can also increase prolactin levels. 

In general, signs and symptoms are due to either the effect of excess hormone secretion (ie, galactorrhea and amenorrhea) or local compression (ie, new-onset or persistent headache, dizziness, visual changes, and vision loss). A review of medications, including estrogen therapy, and history of fertility or gonadal dysfunction should be documented. Elevated prolactin levels can result in secondary hypogonadism.¹

Note: While the case patient is female, it should be emphasized that prolactinomas do occur in men. The incidence is, overall, low. In addition to the symptoms listed above, men can present with decreased libido and infertility.¹

Q: What additional diagnostic tests should be ordered as part of the work-up of galactorrhea and amenorrhea in this patient?

Laboratory evaluation should include a repeat serum prolactin test, measurements of TSH and free T4, and a pregnancy test. (A serum testosterone level should be checked in men.) If the results come back normal and if other diagnoses are excluded, the most likely diagnosis is a prolactinoma. In this case, a pituitary MRI should be obtained. Visual field testing can be performed in individuals with specific visual complaints, especially loss or impairment of peripheral vision.

Q: What is the incidence of prolactinoma in the general population?

Prolactin-secreting adenomas, or prolactinomas, are the most common type of pituitary adenoma, accounting for approximately 60% overall.¹ They occur at a frequency of six to 10 cases per million each year.² Prolactinomas are almost always benign; malignant tumors are extremely rare.³

Tumors are classified as microadenomas or macroadenomas, depending on the size. A microadenoma is defined as an intrasellar mass less than 10 mm in diameter. A macroadenoma, defined as larger than 10 mm in diameter, can cause enlargement of the sella turcica.^1,4 The larger the size of the prolactinoma, the greater the prolactin level and higher the likelihood of mass-effect symptoms.⁴

Q: What are the options for treatment of a prolactinoma?

There are several options for treatment of prolactinomas. After discussing all of the available options with the patient, the choice of therapy should be determined by the patient’s desires and potential plans for pregnancy. It is acceptable to observe the tumor with serial MRIs and serum prolactin measurements, provided the tumor is very small and the patient is asymptomatic.⁴

Medication therapy involves treatment with a dopamine agonist, which directly inhibits prolactin secretion by the tumor and therefore suppresses tumor growth. The goal of medication therapy is to suppress the prolactin level to normal range and restore gonadal function. The two dopamine agonists used are bromocriptine and cabergoline. 

Bromocriptine was the first drug available in the United States to effectively treat pituitary adenomas. Its most common adverse effects include nausea, vomiting, dizziness, and postural hypotension. These effects can be minimized or avoided if the drug is started at a low dose, gradually increased, and taken at bedtime. The adverse effects usually subside with continued use; however, in some patients they persist and therefore the drug has to be discontinued.

Cabergoline is a non-ergot dopamine agonist that is more efficacious, overall better tolerated, and longer acting than bromocriptine. It is dosed twice weekly, whereas bromocriptine is dosed once daily.⁴ One factor to consider in a female patient is whether she is of child-bearing age and is interested in conception. Both bromocriptine and cabergoline are designated as category B; however, in animal studies cabergoline has been associated with maternal toxicity, increase in fetal death, and growth retardation and death due to decreased milk secretion by the mother. Therefore, it should only be used during pregnancy if the need has been clearly established.

Dopamine agonists are approximately 80% to 90% effective in decreasing prolactin levels and reducing tumor size in microadenomas and 60% to 70% in macroadenomas. The major drawback of using medication is that it does not always provide permanent results. Hyperprolactinemia and tumor growth can resume upon discontinuation of the drug, even if the patient has taken it for several years.¹ The rate of recurrence after discontinuing therapy can be anywhere from 26% to 69%, and the highest likelihood occurs within a year of withdrawal.⁴ Close clinical follow-up is thus important.

Surgery, typically a transphenoidal resection, is performed by a neurosurgeon. Success of surgery is based on tumor size and basal prolactin level prior to the procedure. It is more effective in restoring normal prolactin levels and resolution of symptoms in microadenomas than in macroadenomas. Progressive vision loss, pituitary apoplexy, and intolerance to dopamine agonists are indications for surgery.¹

Radiation therapy is reserved for those patients who have residual tumors postsurgery and have not responded to or are intolerant to dopamine agonists. Response to radiation is slow; it can sometimes take several years to achieve full effect. Gamma-knife radiation is sometimes used, but experience with this procedure is limited thus far in prolactinomas.

Overall, the vast majority of prolactinomas are benign and fairly straightforward to manage clinically.³           

REFERENCES
1. Greenspan F, Gardner D. Basic & Clinical Endocrinology, 7th ed. New York: McGraw-Hill; 2004.

2. Ciccarelli A, Daly A, Beckers A. The epidemiology of prolactinomas. Pituitary. 2005;8(1):3-6.

3. Casanueva FF, Molitch ME, Schlechte JA, et al. Guidelines of the Pituitary Society for the diagnosis and management of prolactinomas. Clin Endocrinol (Oxf). 2006;65(2):265-273.

4. Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society Clinical Practice Guideline. J Clinical Endocrinol Metab. 2011;96(2):273-288.

A 42-year-old obese woman with type 2 diabetes, diabetic retinopathy, hyper­tension, and hirsutism presents to discuss an elevated prolactin level of 144.8 ng/mL (normal range, 4.8 to 23.3 ng/mL) found by her Ob-Gyn two months ago. She complained of galactorrhea and no menses for one year. A repeat prolactin level was also elevated, at 109 ng/mL.

A pituitary MRI with contrast showed a “subtle area of delayed enhancement in the right pituitary, consistent with a 5-mm microadenoma.” The patient was prescribed the dopamine agonist cabergoline (0.25 mg, to be taken twice a week), with a plan to follow up in two to three months.

Q: In obtaining a thorough history, what additional questions should be asked of this patient?

There are many causes of hyperprolactinemia. Factors that can increase prolactin secretion include pregnancy, nursing, physiologic stress, estrogen use, polycystic ovary syndrome, hypothyroidism, and chronic renal or hepatic failure. Head trauma, use of certain medications (verapamil, neuroleptics, antipsychotics, and antidepressants), and presence of nonsecretory sellar or suprasellar masses can also increase prolactin levels. 

In general, signs and symptoms are due to either the effect of excess hormone secretion (ie, galactorrhea and amenorrhea) or local compression (ie, new-onset or persistent headache, dizziness, visual changes, and vision loss). A review of medications, including estrogen therapy, and history of fertility or gonadal dysfunction should be documented. Elevated prolactin levels can result in secondary hypogonadism.¹

Note: While the case patient is female, it should be emphasized that prolactinomas do occur in men. The incidence is, overall, low. In addition to the symptoms listed above, men can present with decreased libido and infertility.¹

Q: What additional diagnostic tests should be ordered as part of the work-up of galactorrhea and amenorrhea in this patient?

Laboratory evaluation should include a repeat serum prolactin test, measurements of TSH and free T4, and a pregnancy test. (A serum testosterone level should be checked in men.) If the results come back normal and if other diagnoses are excluded, the most likely diagnosis is a prolactinoma. In this case, a pituitary MRI should be obtained. Visual field testing can be performed in individuals with specific visual complaints, especially loss or impairment of peripheral vision.

Q: What is the incidence of prolactinoma in the general population?

Prolactin-secreting adenomas, or prolactinomas, are the most common type of pituitary adenoma, accounting for approximately 60% overall.¹ They occur at a frequency of six to 10 cases per million each year.² Prolactinomas are almost always benign; malignant tumors are extremely rare.³

Tumors are classified as microadenomas or macroadenomas, depending on the size. A microadenoma is defined as an intrasellar mass less than 10 mm in diameter. A macroadenoma, defined as larger than 10 mm in diameter, can cause enlargement of the sella turcica.^1,4 The larger the size of the prolactinoma, the greater the prolactin level and higher the likelihood of mass-effect symptoms.⁴

Q: What are the options for treatment of a prolactinoma?

There are several options for treatment of prolactinomas. After discussing all of the available options with the patient, the choice of therapy should be determined by the patient’s desires and potential plans for pregnancy. It is acceptable to observe the tumor with serial MRIs and serum prolactin measurements, provided the tumor is very small and the patient is asymptomatic.⁴

Medication therapy involves treatment with a dopamine agonist, which directly inhibits prolactin secretion by the tumor and therefore suppresses tumor growth. The goal of medication therapy is to suppress the prolactin level to normal range and restore gonadal function. The two dopamine agonists used are bromocriptine and cabergoline. 

Bromocriptine was the first drug available in the United States to effectively treat pituitary adenomas. Its most common adverse effects include nausea, vomiting, dizziness, and postural hypotension. These effects can be minimized or avoided if the drug is started at a low dose, gradually increased, and taken at bedtime. The adverse effects usually subside with continued use; however, in some patients they persist and therefore the drug has to be discontinued.

Cabergoline is a non-ergot dopamine agonist that is more efficacious, overall better tolerated, and longer acting than bromocriptine. It is dosed twice weekly, whereas bromocriptine is dosed once daily.⁴ One factor to consider in a female patient is whether she is of child-bearing age and is interested in conception. Both bromocriptine and cabergoline are designated as category B; however, in animal studies cabergoline has been associated with maternal toxicity, increase in fetal death, and growth retardation and death due to decreased milk secretion by the mother. Therefore, it should only be used during pregnancy if the need has been clearly established.

Dopamine agonists are approximately 80% to 90% effective in decreasing prolactin levels and reducing tumor size in microadenomas and 60% to 70% in macroadenomas. The major drawback of using medication is that it does not always provide permanent results. Hyperprolactinemia and tumor growth can resume upon discontinuation of the drug, even if the patient has taken it for several years.¹ The rate of recurrence after discontinuing therapy can be anywhere from 26% to 69%, and the highest likelihood occurs within a year of withdrawal.⁴ Close clinical follow-up is thus important.

Surgery, typically a transphenoidal resection, is performed by a neurosurgeon. Success of surgery is based on tumor size and basal prolactin level prior to the procedure. It is more effective in restoring normal prolactin levels and resolution of symptoms in microadenomas than in macroadenomas. Progressive vision loss, pituitary apoplexy, and intolerance to dopamine agonists are indications for surgery.¹

Radiation therapy is reserved for those patients who have residual tumors postsurgery and have not responded to or are intolerant to dopamine agonists. Response to radiation is slow; it can sometimes take several years to achieve full effect. Gamma-knife radiation is sometimes used, but experience with this procedure is limited thus far in prolactinomas.

Overall, the vast majority of prolactinomas are benign and fairly straightforward to manage clinically.³           

REFERENCES
1. Greenspan F, Gardner D. Basic & Clinical Endocrinology, 7th ed. New York: McGraw-Hill; 2004.

2. Ciccarelli A, Daly A, Beckers A. The epidemiology of prolactinomas. Pituitary. 2005;8(1):3-6.

3. Casanueva FF, Molitch ME, Schlechte JA, et al. Guidelines of the Pituitary Society for the diagnosis and management of prolactinomas. Clin Endocrinol (Oxf). 2006;65(2):265-273.

4. Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society Clinical Practice Guideline. J Clinical Endocrinol Metab. 2011;96(2):273-288.