Gynecology

Pregnancy and Diabetes

Gestational Diabetes
About 1 to 3% of pregnant women develop diabetes during pregnancy. Of all the women who have diabetes during pregnancy, 90% have gestational diabetes. Gestational diabetes is between 24-28 weeks. Unrecognized and untreated, gestational diabetes can increase the risk of health problems for pregnant women and their fetus and the risk of death for the fetus.

40% of women with a history of gestational diabetes develop diabetes at some point in the future.
Most women with gestational diabetes can control blood glucose levels with dietary changes, while 10-15% may require insulin injections.

Because gestational diabetes typically occurs late in the second trimester when the baby’s body is already formed, it does not usually increase the risk of birth defects, but is associated with a chance for
delivering a large baby. If gestational diabetes is not well controlled, there is an increased chance for the baby to have hypoglycemia and breathing problems at birth.

In rare cases where gestational diabetes is present in the first trimester, there may be a small increased risk for birth defects similar to that seen with other forms of diabetes.

Risks of Diabetes During Pregnancy: If diabetes is poorly controlled early in the pregnancy, the risk of an early miscarriage and significant birth defects is increased. Babies born to diabetic women tend to be larger than those born to women without diabetes; however, if diabetes is poorly controlled, fetal growth can be excessive.


A large fetus is less likely to pass easily Consequently, cesarean is often necessary.
The fetus's lungs also tend to mature slowly.
Risk of preeclampsia is increased.
Newborns are at increased risk of having low sugar, low calcium, and high bilirubin levels in the blood.

For pregnant women with poor control,

the risk of birth defects is about 6-10%; this is about twice the chance for well controlled.
For those with extremely poor control in the first trimester, there may be up to a 20% risk for birth defects.Some of the associated birth defects include spinal cord defects (spina bifida), heart defects, skeletal defects, and defects in the urinary, reproductive, and digestive systems.

Prepregnancy management of women with preexisting diabetes

If a reduction in diabetes-associated neonatal morbidity is to be achieved, counsel the patient before conception and perform a medical risk assessment in all women with overt diabetes and those with a history of gestational diabetes mellitus during a previous pregnancy.

Perform a thorough assessment of cardiovascular, renal, and ophthalmologic status.

Institute a regimen of frequent and regular monitoring of both preprandial and postprandial capillary glucose levels.
• Fasting plasma glucose –90-99 mg/dL
• One-hour postprandial plasma glucose less than 140 mg/dL
• Two-hour postprandial plasma glucose less than 120-127 mg/dL

The insulin regimen should result in a smooth glucose profile throughout the day, with no hypoglycemic reactions between meals or at night. Initiate the regimen early enough before pregnancy so that the glycohemoglobin level is lowered into the reference range for at least 3 months before conception.

Patients should take a prenatal vitamin containing at least 1.0 mg of folic acid daily for at least 3 months prior to conception to minimize the risk of neural tube defects in the fetus.


Pregnancy management of diabetes.
Dietary therapy
The goal is to avoid single large meals and foods with a large percentage of simple carbohydrates.
6 feedings per day is preferred, with 3 major meals and 3 snacks to limit the amount of energy intake presented to the bloodstream at any interval. Examples include foods with complex carbohydrates, such as whole grain breads and legumes.

Carbohydrates should account for no more than 50% of the diet, with protein and fats equally accounting for the remainder.
However, moderate restriction of carbohydrates to 35–40% has been shown to decrease maternal glucose levels and improve maternal and fetal outcomes.

Glucose monitoring

The availability of capillary glucose test strips should now be considered the standard of care for pregnancy monitoring.
A typical schedule involves capillary glucose checks upon awakening in the morning, 1 hour after breakfast, before and after lunch, before dinner, and at bedtime.. Superb glycemic control requires attention to both preprandial and postprandial glucose levels.

Insulin therapy

The goal of insulin therapy during pregnancy is to achieve glucose profiles similar to those of nondiabetic pregnant women Insulins lispro, aspart, regular and NPH are well-studied in pregnancy and regarded as safe and efficacious. Insulin glargine is less well-studied, and given its long pharmacologic effect, may exacerbate periods of maternal hypoglycemia.

As pregnancy progresses, the increasing fetal demand for glucose the progressive lowering of fasting and between-meal blood sugar levels increases the risk of symptomatic hypoglycemia. Thus, any insulin regimen for pregnant women requires combinations and timing of insulin injections quite different from those that are effective in the nonpregnant state.

Further, the regimens must be continuously modified as the patient progresses from the first to the third trimester and insulin resistance rises.

Insulin pump

In a select group of patients, use of an insulin pump may improve glycemic control while enhancing patient convenience. These devices can be programmed to infuse varying basal and bolus levels of insulin, which change smoothly even while the patient sleeps or is otherwise preoccupied.The effectiveness of continuous subcutaneous insulin infusion in pregnancy is well established.


Oral hypoglycemic agents - Glyburide
Glyburide is minimally transported across the human placenta. This is probably largely due to the high plasma protein binding coupled with a short half-life.
Glyburide should not be used in the first trimester because its effects, if any, on the embryo are unknown.

A randomized trial comparing glyburide to insulin was published in 2000, studying 404 pregnancies. At the conclusion of this trial, there was no difference between the groups in the mean maternal blood glucose, the percentage of infants who were large for gestational age, the birthweight, or neonatal complications.

Since this study, several prospective and retrospective studies involving more than 775 pregnancies have concluded glyburide is equally as safe and efficacious as insulin. Glyburide has been shown to be safe in breastfeeding, with no transfer into human milk.