ANTIPHOSPHOLIPID SYNDROME

Antiphospholipid syndrome is associated with thrombophilia and recurrent pregnancy loss. Antiphospholipid antibodies are found in 2% to 5% of the general healthy population, but they also may be associated with systemic lupus erythematosus and other rheumatic diseases. Obstetric complications arise from the prothrombotic effects of the antiphospholipid antibodies on placental funcion. Vasculopathy, infarction, and thrombosis have been identified in mothers with antiphospholipid syndrome. Antiphospholipid syndrome can include fetal growth impairment, placental insufficiency, maternal preeclampsia, and premature birth.

IDIOPATHIC THROMBOCYTOPENIA

Idiopathic thrombocytopenic purpura (ITP) is seen in approximately 1 to 2 per 1000 live births and is an immune process in which antibodies are directed against platelets. Platelet-associated IgG antibodies can cross the placenta and cause thrombocytopenia in the fetus and newborn. The severely thrombocytopenic fetus is at increased risk for intracranial hemorrhage. ITP during pregnancy requires close maternal and fetal management to reduce the risks of life-threatening maternal hemorrhage and trauma to the fetus at delivery. Postnatal management involves observation of the infant’s platelet count. For infants who have evidence of hemorrhage, single-donor irradiated platelets may be administered to control the bleeding. The infant may benefit from an infusion of intravenous immunoglobulin. Neonatal thrombocytopenia usually resolves within 4 to 6 weeks.

SYSTEMIC LUPUS ERYTHEMATOSUS

Immune abnormalities in systemic lupus erythematosus (SLE) can lead to the production of anti-Ro (SS-A) and anti-La (SS-B) antibodies that can cross the placenta and injure fetal tissue. The most serious complication is damage to the cardiac conducting system, which results in congenital heart block. The heart block observed in association with maternal SLE tends to be complete (third degree), although less advanced blocks have been observed. The mortality rate is approximately 20%, and most surviving infants require pacing. Neonatal lupus may occur and is characterized by skin lesions (sharply demarcated erythematous plaques or central atrophic macules with peripheral scaling with predilection for the eyes, face, and scalp), thrombocytopenia, autoimmune hemolysis, and hepatic involvement.

NEONATAL HYPERTHYROIDISM

Graves’ disease is associated with thyroid-stimulating antibodies. The prevalence of clinical hyperthyroidism in pregnancy has been reported to be about 0.1% to 0.4% and is the most common endocrine disorder during pregnancy after diabetes. Neonatal hyperthyroidism is due to the transplacental passage of thyroid-stimulating antibodies; hyperthyroidism can appear rapidly within the first 12 to 48 hours. Symptoms may include intrauterine growth restriction, prematurity, goiter (may cause tracheal obstruction), exophthalmos, stare, craniosynostosis (usually coronal), flushing, congestive heart failure, tachycardia, arrhythmias, hypertension, hypoglycemia, thrombocytopenia, and hepatosplenomegaly. Treatment includes propylthiouracil, iodine drops, and propranolol. Autoimmune neonatal hyperthyroidism usually resolves in 2 to 4 months.

DIABETES MELLITUS

Diabetes mellitus that develops during pregnancy (gestational diabetes is noted in about 5% of women) or diabetes that is present before pregnancy adversely influences fetal and neonatal well-being. The effect of diabetes on the fetus depends in part on the severity of the diabetic state: age of onset of diabetes, duration of treatment with insulin, and presence of vascular disease. Poorly controlled maternal diabetes leads to maternal and fetal hyperglycemia that stimulates the fetal pancreas, resulting in hyperplasia of the islets of Langerhans. Fetal hyperinsulinemia results in increased fat and protein synthesis and fetal macrosomia, producing a fetus that is large for gestational age. After birth, hyperinsulinemia persists, resulting in fasting neonatal hypoglycemia. Strictly controlling maternal diabetes during pregnancy and preventing hyperglycemia during labor and delivery prevent macrosomic fetal growth and neonatal hypoglycemia. Additional problems of the diabetic mother and her fetus and newborn are summarized in Table 59-2.

OTHER CONDITIONS

Other maternal illnesses, such as severe pulmonary disease (cystic fibrosis), cyanotic heart disease, and sickle cell anemia, may reduce oxygen availability to the fetus. Severe hypertensive or diabetic vasculopathy can result in uteroplacental insufficiency. In addition to the fact that the fetus is directly affected by maternal illnesses, the fetus and the newborn may be adversely affected by the medications used to treat the maternal illnesses. These effects may appear as teratogenesis (Table 59-3) or as an adverse metabolic, neurologic, or cardiopulmonary adaptation to extrauterine life (Table 59-4). Acquired infectious diseases of the mother also may affect the fetus or newborn adversely.

TABLE 59-3 Common Teratogenic Drugs

* Trimethoprim, triamterene, phenytoin, primidone, phenobarbital, carbamazepine.

TABLE 59-4 Agents Acting on Pregnant Women That May Adversely Affect the Newborn Infant

CNS, central nervous system; G6PD, glucose-6-phosphate dehydrogenase; IUGR, intrauterine growth restriction; PPHN, persistent pulmonary hypertension of the newborn.

From Stoll BJ, Kliegman RM: The fetus and neonatal infant. In Behrman RE, Kliegman RM, Jenson HB, editors: Nelson Textbook of Pediatrics, 16th ed, Philadelphia, 2000, Saunders.