Effects of smoking and preeclampsia on birth weight for gestational age

Abstract

Objective: A counterintuitive interaction between smoking during pregnancy and preeclampsia on birth weight for gestational age (BWGA) outcomes was recently reported. In this report, we examine the relationship between these factors in a well-documented study population with exposure data on trimester of maternal smoking.

Methods: Preeclamptic (n = 238), gestational hypertensive (n = 219), and normotensive women (n = 342) were selected from live-births to nulliparous Iowa women. Disease status was verified by medical chart review, and smoking exposure was assessed by self-report. Fetal growth was assessed as z-score of BWGA. Multiple linear regression was used to test for the association of maternal smoking and preeclampsia with BWGA z-score.

Results: There was no interaction between smoking with preeclampsia or gestational hypertension on fetal growth. BWGA z-scores were significantly lower among women with preeclampsia and those who smoked any time during pregnancy (β = −0.33, p = <0.0001 and β = −0.25, p = 0.05) compared to normotensive and non-smoking women, respectively. Infants of women with gestational hypertension were comparable in size to infants born to normotensive women.

Conclusions: Women who developed preeclampsia and those who smoked during pregnancy delivered infants that were significantly smaller than infants of women who did not develop preeclampsia and non-smoking women, respectively.

• Epidemiology
• fetal growth
• low birth weight
• pregnancy
• z-score

Declaration of interest

None of the authors have any conflicts of interest to disclose. This study was supported by SOPHIA: National Institute of Child Health and Human Development, National Institutes of Health R01 HD39753; IHIPS: National Institute of Child Health and Human Development, National Institutes of Health NICHD R01 HD39753; and National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health R21 AI1068111.

Supplemental Table available online

Supplemental Table 1