An ounce of prevention: The evidence supporting periconception health care

In the US, rubella infection is most likely to occur among Hispanic patients (especially foreign-born patients) and among families that refuse immunization.⁴¹ A review of 12 cases of congenital rubella after an outbreak in the early 1990s found that more than 50% of the mothers had 2 or more medical visits where rubella testing/immunization could have been done. Similarly, another study found that 62% of women who gave birth to infants with congenital rubella syndrome had at least 1 missed opportunity for immunization prior to that pregnancy.⁴²

Although no prospective studies confirm this observation, the authors calculated that the single most effective policy for prevention of congenital rubella syndrome would be screening pregnant women for rubella immunity and postpartum immunization of nonimmune women (SOR: C).

Alcohol

The Institute of Medicine recognizes alcohol-related birth defects (ARBD) and alcohol-related neurodevelopmental disorder (ARND) in addition to fetal alcohol syndrome (FAS) as potential effects of alcohol use in pregnancy and the periconception period.⁴³

A diagnosis of FAS requires characteristic facial anomalies, growth retardation, and neurodevelopmental abnormalities. A category of partial FAS does exist; affected children have some of the characteristic facial anomalies, and either growth retardation, neurodevelopmental abnormalities, or cognitive/behavioral abnormalities with no other explanation.

ARBD includes a confirmed history of maternal alcohol use plus one or more congenital defects (most commonly cardiac, renal, vision, hearing, or skeletal. ARND requires a confirmed history of maternal alcohol use and either the neurodevelopmental abnormalities or cognitive/behavioral abnormalities found in partial FAS.

The prevalence of FAS in the US population is estimated at 0.5 to 2 per 1000 births, with up to 10/1000 newborns having some effect from alcohol exposure.⁴⁴ The rate of FAS is more than 20 times higher in the US compared with other countries, including European countries, partially due to differences in diagnosis.⁴⁵

Strict abstinence required?

Whether a safe threshold of alcohol consumption exists before or during pregnancy is a point of controversy. Many US authorities recommend against any alcohol intake before or during pregnancy. The effects of alcohol on a fetus depend on the amount of alcohol consumed at one time, timing of alcohol consumption in gestation, and duration of alcohol use in pregnancy.

This is complicated by the fact that studies have used varying definitions of light and heavy alcohol use, with categories that often overlap between different studies.⁴⁶ Binge drinking (defined as more than 5 drinks on a single day), even when episodic, is more dangerous to fetal brain development than nonbinge drinking.⁴⁷

Less severe problems can occur

Although a high level of alcohol use in pregnancy is associated with more severely affected offspring, a 1984 study of 31,000 pregnancies showed a higher risk of growth retardation if a mother had even 1 drink a day (LOE: 2b).⁴⁸ A 2001 study of more than 600 urban African American children showed continued behavioral effects of alcohol at ages 6 to 7 with low levels (1 drink daily) of maternal alcohol consumption (LOE: 2b).⁴⁹

Some intervention attempts show promise

A review of trials in which physicians briefly counseled nonpregnant women who were problem drinkers found no consistent decrease in drinking.⁵⁰ Trials of personalized advice to pregnant women have also found it to be no more effective than written information alone.⁵¹ A written self-help manual, however, did improve cessation rates among women at a prenatal clinic.⁵²

The CDC sponsored a pilot project to encourage alcohol cessation and effective contraception in women at risk for alcohol-exposed pregnancy.⁵³ Although not a controlled trial, this more extensive intervention showed promise. Of the 143 women enrolled, 68.5% had either stopped their alcohol consumption or were using effective contraception by the 6-month follow up.

Applying the evidence

Written information about the risks of alcohol use in pregnancy should be provided to pregnant women who consume alcohol (SOR: B). There is not enough data to recommend physician counseling for alcohol cessation before or during pregnancy. More comprehensive interventions may be more effective, but have yet to be fully studied. No studies have evaluated neonatal outcomes in the offspring of women who are counseled on alcohol cessation in the periconception period.

Acknowledgments

The authors would like to thank Robert Taylor, MD and Scott Fields, MD for their assistance in reviewing this manuscript. The authors have no conflicts of interest to report.