Pregnancy-Influenced Issues

Gastrointestinal Tract

• Constipation commonly occurs during pregnancy. Institute education, physical exercise, and increased intake of dietary fiber and fluid. If additional therapy is warranted, give supplemental fiber and/or a stool softener. Polyethylene glycol, lactulose, sorbitol, and magnesium and sodium salts can be used intermittently short term. Senna and bisacodyl can be used occasionally. Avoid castor oil and mineral oil.
• Therapy for gastroesophageal reflux disease includes lifestyle and dietary modifications, for example, small, frequent meals; alcohol, tobacco, and caffeine avoidance; food avoidance 3 hours before bedtime; and elevation of the head of the bed. If necessary, initiate aluminum, calcium, or magnesium antacids; sucralfate; or cimetidine or ranitidine. Proton pump inhibitors are options if response to histamine 2 (H2)–receptor blockers is inadequate. Avoid sodium bicarbonate and magnesium trisilicate.
• Therapy for hemorrhoids includes high intake of dietary fiber, adequate oral fluid intake, and use of sitz baths. If response is inadequate, laxatives and stool softeners can be used. Topical anesthetics, skin protectants, and astringents may help irritation and pain. Topical hydrocortisone may reduce inflammation and pruritus.
• Nonpharmacologic treatments for nausea and vomiting include eating small, frequent meals; avoiding fatty foods; and acupressure. Pharmacotherapy may include antihistamines (e.g., doxylamine), pyridoxine, and dopamine antagonists (e.g., metoclopramide). Ondansetron can be used when other agents have failed, and ginger is considered safe and effective. Dexamethasone and prednisolone have been effective for hyperemesis gravidarum (i.e., severe nausea and vomiting causing weight loss >5% of prepregnancy weight, dehydration, and ketonuria), but the risk of oral clefts is increased.

Gestational Diabetes Mellitus

• First-line therapy for all women with gestational diabetes mellitus (GDM) includes dietary modification and caloric restrictions for obese women. Daily self-monitoring of blood glucose is required. If nutritional intervention fails to achieve fasting plasma glucose levels of less than 90 to 99 mg/dL (5–5.5 mmol/L), 1-hour postprandial plasma glucose concentrations of 140 mg/dL or less (7.8 mmol/L), or 2-hour postprandial levels of less than 120 to 127 mg/dL (6.7–7 mmol/L), therapy with recombinant human insulin should be instituted; glyburide may be considered an alternative. Metformin may also be considered, but it crosses the placenta and is less studied

Hypertension

• Hypertension (HTN) during pregnancy includes gestational HTN (i.e., HTN without proteinuria developing after 20 weeks’ gestation), preeclampsia (i.e., HTN with proteinuria), chronic HTN (preexisting HTN or developing before 20 weeks’ gestation), and preeclampsia superimposed on chronic HTN. Eclampsia, a medical emergency, is preeclampsia with seizures. HTN in pregnancy is a diastolic blood pressure of 90 mm Hg or more based on the average of two or more measurements from the same arm.
• For women at risk for preeclampsia, low-dose aspirin (75–81 mg/day) after 12 weeks’ gestation reduces the risk for preeclampsia by 17%. Aspirin also reduces the risk of preterm birth by 8% and fetal and neonatal death by 14%. Calcium, 1 to 2 g/day, decreases the relative risk of HTN by 30% and preeclampsia by 48%. Calcium, 1 g/day, is appropriate for all pregnant women.
• Antihypertensive drug therapy is discussed later under Chronic Illnesses in Pregnancy.
• Magnesium sulfate is used to decrease the risk of progression of preeclampsia to eclampsia and to treat eclamptic seizures. Avoid diazepam and phenytoin.

Thyroid Abnormalities

• Gestational transient thyrotoxicosis usually resolves by 20 weeks’ gestation. Antithyroid medication is usually not needed.

Venous Thromboembolism

For treatment of acute thromboembolism during pregnancy, low-molecular-weight heparin is preferred over unfractionated heparin. Continue treatment throughout pregnancy and for 6 weeks after delivery. Duration of therapy should not be less than 3 months. Avoid warfarin because it may cause fetal bleeding, malformations of the nose, stippled epiphyses, or CNS anomalies.