Bosny J. Pierre-Louis

Levels of excess infant deaths attributable to maternal smoking during pregnancy in the United States.

Objectives: The objectives of the study were: 1) To determine the risk of infant mortality associated with prenatal cigarette smoking; 2) To assess whether the relationship, if existent, was dose-dependent; 3) To explore the morbidity pathway that explains the effect of tobacco smoke on infant mortality, and 4) to compute excess infant deaths attributable to maternal smoking in the United States. Methods: Retrospective cohort study on 3,004,616 singleton live births that occurred in 1997 in the United States using the US national linked birth/infant death data. Excess infant deaths due to maternal smoking were computed using the population-attributable risk (PAR). Results: Overall, 13.2% of pregnant women who delivered live births in 1997 smoked during pregnancy. The rate of infant mortality was 40% higher in this group as compared to nonsmoking gravidas (P < 0.0001). This risk increased with the amount of cigarettes consumed prenatally in a dose-dependent fashion (p for trend <0.0001). Small-for-gestational age rather than preterm birth is the main mechanism through which smoking causes excess infant mortality. We estimated that about 5% of infant deaths in the United States were attributable to maternal smoking while pregnant, with variations by race/ethnicity. The proportion of infant deaths attributable to maternal smoking was highest among American Indians at 13%, almost three times the national average. If pregnant smokers were to halt tobacco use a total of 986 infant deaths would be averted annually. Conclusions: Smoking during pregnancy accounts for a sizeable number of infant deaths in the United States. This highlights the need for infusion of more resources into existing smoking cessation campaigns in order to achieve higher quit rates, and substantially diminish current levels of smoking-associated infant deaths.

Mode of delivery and neonatal survival of infants with isolated gastroschisis.

OBJECTIVE: We sought to compare neonatal survival of infants with gastroschisis by mode of delivery. METHODS: We conducted a retrospective cohort study on infants with gastroschisis who were delivered in New York State from 1983 through 1999. We compared neonatal mortality between infants born vaginally and those delivered by cesarean using adjusted hazard ratios derived from Cox proportional hazards regression models. RESULTS: A total of 354 infants were found to have isolated gastroschisis. Of these, 174 were delivered vaginally, whereas 180 were delivered by cesarean. Neonatal mortality was registered among 18 infants (5.1%); 12 (6.9%) in the vaginal and 6 (3.3%) in the cesarean group. After controlling for potential confounders, the risk for neonatal demise was similar in both the vaginal and cesarean subcohorts (adjusted hazard ratio 0.84, 95% confidence interval [CI] 0.29–2.43). Preterm birth was the morbidity pathway that explained the early demise of infants with gastroschisis, irrespective of mode of delivery (adjusted hazard ratio 3.4, 95% CI 1.10–10.4) whereas small for gestational age did not predict mortality (adjusted hazard ratio 1.04, 95% CI 0.13–8.14). CONCLUSION: In this study the mode of delivery was not found to be associated with neonatal survival of infants with gastroschisis. Preterm birth rather than small for gestational age was the predictor of neonatal death among gastroschisis infants. LEVEL OF EVIDENCE: III

Effect of a levonorgestrel intrauterine system on women with type 1 diabetes: a randomized trial.

OBJECTIVE: Women with diabetes need safe, effective contraception. Although intrauterine devices provide superior contraception, concerns remain that progestin absorbed systemically from the levonorgestrel-releasing device may impair carbohydrate metabolism. To examine the effect of the levonorgestrel-releasing intrauterine system on glucose metabolism in diabetic women. METHODS: We randomly assigned 62 women with uncomplicated insulin-dependent diabetes mellitus to either a levonorgestrel-releasing or a copper T 380A intrauterine device. The primary outcome to assess glucose metabolism was glycosylated hemoglobin; fasting serum-glucose levels and daily insulin dose requirements over 12 months of observation were examined as well. RESULTS: Outcome data were available for 29 women using the levonorgestrel-releasing and 30 using the copper device. At 12 months, mean glycosylated levels were similar for women of the 2 groups (6.3%, standard deviation [SD] ± 1.5 compared with 6.3%, SD ± 1.3, respectively). The same was true for mean fasting-serum glucose levels (7.4 mM, SD ± 4.2 compared with 7.5 mM, SD ± 4.2) and daily insulin doses (35.1 units, SD ± 12.8 compared with 36.4 units, SD ± 9.0). No important differences were noted at either 6 weeks or 6 months. CONCLUSION: The levonorgestrel-releasing device had no adverse effect on glucose metabolism, even at the 6-week observation when systemic levels of levonorgestrel would have been higher than at later observations. Concern about a potential adverse effect of this contraceptive on glucose control is unwarranted, and its use in women with diabetes should be liberalized. LEVEL OF EVIDENCE: I

Omphalocele, advanced maternal age, and fetal morbidity outcomes

In this study we wanted to determine if the risk for adverse neonatal outcome among omphalocele‐affected fetuses is increased among older gravidas. This was a retrospective cohort study on live‐born infants with omphalocele delivered in New York State from 1983 through 1999. We compared infants of older (≥35 years) with those of younger (<35 years) mothers with respect to the following fetal morbidity indices: low birth weight and very low birth weight, preterm and very preterm, and small for gestational age. We used adjusted odds ratios to approximate relative risks. Data on a total of 1,010 infants with omphalocele were analyzed. Mean gestational age and birth weight were similar in both maternal age categories: mean ± standard deviation (SD) for infants with omphalocele born to older mothers = 37.4 weeks ± 3.9 versus 38.0 weeks ± 5.1 for those of younger mothers (P = 0.2); mean birth weights ± SD for infants with omphalocele born to older mothers = 2,813 ± 871.1 versus 2,958 ± 809.9 for those of younger mothers (P = 0.08). Also, the two maternal age sub‐groups did not differ with respect to the fetal morbidity outcome: low birth weight (OR = 0.95; 95% CI = 0.60–1.51), very low birth weight (OR = 0.78; 95% CI = 0.36–1.69), preterm (OR = 0.95; 95% CI = 0.58–1.57), very preterm (OR = 0.73; 95% CI = 0.34–1.58), and SGA (OR = 1.00; 95% CI = 0.44–2.27). Thus, advanced maternal age does not appear to be a risk factor for fetal morbidity outcomes among omphalocele‐affected fetuses. This information is potentially useful in counseling affected parents.