Maternal smoking does not affect fetal size as measured in the mid-second trimester

Acta Obstet Gynecol Scand. 2007;86(2):156-60. doi: 10.1080/00016340600984696.


Background: Cigarette smoking during pregnancy is causally related to birthweight, but we do not know whether fetal growth restriction is a continuous process or, if not, at what stage of pregnancy it affects weight gain.

Material and methods: A random sample of para 1 and 2 mothers, drawn from the population of pregnant women in Bergen and Trondheim, Norway, and Uppsala, Sweden, were examined by a detailed questionnaire concerning smoking habits, menstrual history and pregnancy dating, and subjected to morphometric sonography of their fetuses in or around week 17. Of the 547 study participants, 31.9% were smokers. Gestational age was primarily determined by the last menstrual period [LMP], except in those with irregular cycles, and in 30 cases (6.6% of those with regular cycles) in whom the biparietal diameter [BPD]-determined age deviated >14 days from the LMP-based date.

Results: The analysis did not reveal any statistically significant differences between the fetuses of non-smokers, light smokers (0-9 cigarettes per day) and heavy (10+ cigarettes per day) smokers, regarding BPD, mean abdominal diameter [MAD] femur length [FL], and a 'body contour index': [BPD+FL]/MAD.

Conclusion: Tobacco-induced fetal growth restriction probably begins after gestational week 17.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Anthropometry
  • Female
  • Femur / embryology
  • Fetal Development / drug effects*
  • Fetal Weight / drug effects*
  • Head / embryology
  • Humans
  • Longitudinal Studies
  • Pregnancy
  • Pregnancy Trimester, Second
  • Prospective Studies
  • Smoking / adverse effects*
  • Surveys and Questionnaires
  • Ultrasonography, Prenatal