Simultaneous fetal and maternal cotinine levels in pregnant women smokers

Am J Obstet Gynecol. 1993 Mar;168(3 Pt 1):781-2. doi: 10.1016/s0002-9378(12)90818-2.


Objective: Our purpose was to determine the simultaneous concentrations of serum cotinine in both fetal and maternal blood.

Study design: Serum cotinine levels were measured in 11 maternal-fetal pairs at percutaneous umbilical blood sampling. Statistical analysis was performed by means of a one-group t test to determine whether the ratio of fetal-to-maternal cotinine was significantly different from 1.

Results: Fetal cotinine levels ranged from 75% to 110% of maternal values (mean ratio 0.90, 95% confidence interval 0.83 to 0.97). Fetal levels were significantly lower than maternal concentrations (p = 0.02).

Conclusions: Cotinine, a metabolite of nicotine used to quantify exposure to tobacco smoke, readily gains access to the fetal circulation. Fetal cotinine concentrations in pregnant women smokers are, on average, 90% of maternal values throughout gestation.

MeSH terms

  • Cotinine / blood*
  • Female
  • Fetal Blood / metabolism*
  • Gestational Age
  • Humans
  • Pregnancy
  • Smoking / blood*


  • Cotinine