The effects of prenatal secondhand smoke exposure on preterm birth and neonatal outcomes

J Obstet Gynecol Neonatal Nurs. Sep-Oct 2010;39(5):525-35. doi: 10.1111/j.1552-6909.2010.01169.x.

Abstract

Objective: To examine the relationship between prenatal secondhand smoke (SHS) exposure, preterm birth and immediate neonatal outcomes by measuring maternal hair nicotine.

Design: Cross-sectional, observational design.

Setting: A metropolitan Kentucky birthing center.

Participants: Two hundred and ten (210) mother-baby couplets.

Methods: Nicotine in maternal hair was used as the biomarker for prenatal SHS exposure collected within 48 hours of birth. Smoking status was confirmed by urine cotinine analysis.

Results: Smoking status (nonsmoking, passive smoking, and smoking) strongly correlated with low, medium, and high hair nicotine tertiles (ρ=.74; p<.001). Women exposed to prenatal SHS were more at risk for preterm birth (odds ratio [OR]=2.3; 95% Confidence Interval [CI] [.96, 5.96]), and their infants were more likely to have immediate newborn complications (OR=2.4; 95% CI [1.09, 5.33]) than nonexposed women. Infants of passive smoking mothers were at increased risk for respiratory distress syndrome (RDS) (OR=4.9; 95% CI [1.45, 10.5]) and admission to a Neonatal Intensive Care Unit (NICU) (OR=6.5; CI [1.29, 9.7]) when compared to infants of smoking mothers (OR=3.9; 95% CI [1.61, 14.9]; OR=3.5; 95% CI [2.09, 20.4], respectively). Passive smokers and/or women with hair nicotine levels greater than .35 ng/ml were more likely to deliver earlier (1 week), give birth to infants weighing less (decrease of 200-300 g), and deliver shorter infants (decrease of 1.1-1.7 cm).

Conclusions: Prenatal SHS exposure places women at greater risk for preterm birth, and their newborns are more likely to have RDS, NICU admissions, and immediate newborn complications.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Biomarkers
  • Case-Control Studies
  • Cotinine / urine
  • Cross-Sectional Studies
  • Female
  • Hair / chemistry
  • Humans
  • Kentucky / epidemiology
  • Male
  • Maternal Exposure / adverse effects*
  • Nicotine / analysis
  • Pregnancy
  • Pregnancy Outcome*
  • Premature Birth / epidemiology
  • Premature Birth / etiology*
  • Regression Analysis
  • Smoking / adverse effects
  • Tobacco Smoke Pollution / adverse effects*
  • Tobacco Smoke Pollution / analysis

Substances

  • Biomarkers
  • Tobacco Smoke Pollution
  • Nicotine
  • Cotinine