Diabetes Mellitus
Because maternal and fetal pathology associated with hyperglycemia is well known, diabetes is the prototype of a condition for which preconceptional counseling is beneficial. Many of these complications can be avoided if conception occurs when glucose control is optimal (Jovanovic and colleagues, 1981). Such control requires either that glucose levels be chronically well regulated—always a goal, but difficult to achieve—or that the woman make necessary changes before attempting conception. Preconceptional counseling can educate her about risks and provide a program designed to reduce them (Bernasko, 2004).
The utility of preconceptional counseling in preventing diabetes-related complications at all stages of pregnancy has been confirmed. Importantly, all studies showed that counseling is associated with significantly fewer malformations.
Dunne and co-workers (1999) reviewed the impact of preconceptional counseling on other diabetes-related neonatal morbidity. Women who received counseling sought prenatal care earlier, had lower hemoglobin A1c levels, and were less likely to smoke during pregnancy. Their outcomes were compared with those of a cohort of women who did not receive such counseling. Of the women who received counseling, none were delivered before 30 weeks compared with 17 percent in the uncounseled group. In addition, the counseled women had fewer macrosomic infants—25 versus 40 percent; they had no growth-restricted infants compared with 8.5 percent; they had no neonatal deaths compared with 6 percent; and their infants had 50 percent fewer admissions to the intensive care nursery—17 versus 34 percent.
Preconceptional counseling also reduces obstetrical complications and health care costs in diabetic women. In a prospective multicenter observational trial from five Michigan centers, Herman and colleagues (1999) confirmed these benefits. They reported that diabetic women who received preconceptional counseling reported for prenatal care 3 weeks earlier than uncounseled women; they had lower hemoglobin A1c levels; they were significantly less likely to require antepartum hospitalization for diabetes control—8 versus 68 percent; and they had significantly fewer hospitalization days—4.5 versus 15.7. Counseled women also had fewer episodes of hypoglycemia and diabetic ketoacidosis; they had no hypertensive complications; and their postpartum stay was 2 days shorter than that of uncounseled women. These improved outcomes were associated with savings of $34,000 in direct medical costs per patient who received counseling.
Epilepsy
Women with epilepsy are two to three times more likely to have infants with structural anomalies than unaffected women (Chang and McAuley, 1998; Wide and associates, 2004). Some reports indicate that epilepsy itself increases the incidence of congenital anomalies, independent of the effects of antiseizure medication. In a recent study, however, Holmes and colleagues (2001) compared 509 epileptic women who took antiseizure medication during pregnancy to 606 who did not. They found that only infants exposed to anticonvulsant medications had an increased incidence of structural anomalies. Fetuses exposed to one drug had significantly fewer malformations than those exposed to two or more drugs—21 versus 28 percent. By contrast, the incidence of defects in fetuses of epileptic mothers who did not take medication was only 8.5 percent—the same as in fetuses of women without seizure disorders. Preconceptional counseling usually includes recommendations to switch to monotherapy with the least teratogenic medication (Adab and colleagues, 2004; American Academy of Neurology, 1998). The risks of antiseizure medication are described in detail in Chapter 14 (see Anticonvulsant Medications).
Epileptic women also are advised to take supplemental folic acid. Biale and Lewenthal (1984) performed a retrospective case-control study to evaluate effects of periconceptional folate supplementation in women taking anticonvulsants. Although 10 of 66 (15 percent) unsupplemented pregnancies resulted in offspring with congenital malformations, none of 33 neonates of supplemented women had anomalies. Depending on the history, a trial period without anticonvulsants also may be recommended.
Other Chronic Diseases
Cox and co-workers (1992) reviewed pregnancy outcomes of 1075 high-risk women who received preconceptional counseling. If they received counseling, 240 women with hypertension, renal disease, thyroid disease, asthma, and heart disease had significantly better outcomes than previous pregnancies. Indeed, 80 percent of those counseled gave birth to a normal infant compared with only 40 percent in the previous uncounseled gestation.