Prenatal Drug Exposure and Drug-Abusing Environments

Research Findings from May, 2003 Director's Report

This section lists selected summaries from NIDA funded research projects that investigate the consequences of prenatal drug exposure. The summaries provided were selected from recent issues of the Director's Report to the National Advisory Council on Drug Abuse. For a more comprehensive listing of NIDA funded projects see the Director's Report.

Effect of Maternal Smoking on Fetal Catecholamine Concentrations at Birth

Catecholamine concentrations in the fetal umbilical artery cord blood from the offspring of smokers were compared to the offspring of nonsmokers. Pregnant women who were self-identified as smokers (>/=10 cigarettes per day throughout pregnancy) or nonsmokers were recruited for study participation. Maternal blood was collected for cotinine concentrations. Umbilical artery cord blood was collected at delivery for arterial pH and catecholamine concentrations. Cord blood was obtained from 51 subjects, including 21 smokers and 30 nonsmokers. Median epinephrine concentrations [304 pg/mL versus 597 pg/mL (Mann-Whitney U = 170; p = 0.006)] and median norepinephrine concentrations [3148 pg/mL versus 6558 pg/mL (Mann-Whitney U = 191; p = 0.006)] were significantly lower in smokers compared with nonsmokers, respectively. After controlling for gestational age, route of delivery, and arterial pH, log-transformed epinephrine concentrations between smokers and nonsmokers were statistically significant (p = 0.03), with a similar trend for log-transformed norepinephrine concentrations (p = 0.07). Analyses of the data using cotinine <20 ng/mL to classify nonsmokers also showed differences in epinephrine concentrations between groups (p = 0.02). These results are consistent with results from animal studies showing that catecholamine concentrations may be affected by prenatal nicotine exposure. Further studies are needed to validate these findings and to examine the specific mechanism by which these differences may arise. Oncken ,C.A., Henry, K.M., Campbell, W.A., Kuhn, C.M., Slotkin, T.A. and Kranzler, H.R. Effect of Maternal Smoking on Fetal Catecholamine Concentrations at Birth. Pediatr Res. 53(1), pp. 119-124, January 2003.

Maternal Smoking During Pregnancy

University of Chicago researchers have reported on fluctuations in women's cigarette smoking during pregnancy, with special attention to implications for the design of clinical interventions and for research on the effects of fetal exposure to cigarettes. Data were analyzed from two independent projects, the National Health Interview Survey 1991 Pregnancy and Smoking Supplement (N=1426), and the Family Health and Development Project, the latter a small (N=60), prospective, clinic-based study. A substantial portion of the women in the large study showed a pattern of repeated cessation and relapse. In the smaller sample, fluctuations in smoking intensity were also substantial. While 48% quit or reduced smoking when they learned of their pregnancy, more than half changed smoking intensity multiple times. The investigators conclude that simple measures of smoking during pregnancy may lead to underestimation of possible fetal impact, and that brief smoking cessations early in pregnancy are likely to be inadequate for many women. Pickett, K.E., Wakschlag, L.S., Dai, L., and Leventhal, B.L. Fluctuations of Maternal Smoking During Pregnancy. Obstetrics and Gynecology, 101, pp. 140-147, 2003.