Body composition, smoking, and spontaneous dizygotic twinning

Fertil Steril. 2010 Feb;93(3):885-93. doi: 10.1016/j.fertnstert.2008.10.012. Epub 2008 Dec 4.


Objective: To examine differences in body composition and smoking between mothers of spontaneous monozygotic and dizygotic twins, while taking into account maternal age, gravidity, and educational attainment.

Design: Retrospective cohort study.

Setting: The Netherlands Twin Register.

Patient(s): Mothers of twins (n = 19,357) registered with the Netherlands Twin Register. Data were selected from mothers of spontaneous monozygotic twins (MZ; n = 5663) and mothers of spontaneous dizygotic twins (DZ; n = 8515).

Intervention(s): None.

Main outcome measure(s): The odds of having spontaneous DZ twins versus spontaneous MZ twins as a function of height, body mass index (BMI), and smoking before pregnancy, after accounting for age, gravidity, and educational attainment.

Result(s): Compared with spontaneous MZ twinning, spontaneous DZ twinning is significantly associated with increasing height (odds ratio, 1.6; 95% confidence interval [CI], 1.5-1.8 for the tallest versus the shortest height quartile), an increased BMI (odds ratio, 1.3; 95% CI, 1.1-1.4 for overweight vs. normal weight), and smoking before the twin pregnancy (odds ratio, 1.4; 95% CI, 1.3-1.5 for smoker vs. nonsmoker). Maternal age and gravidity, but not educational attainment, had to be included in the model.

Conclusion(s): Spontaneous dizygotic twinning is associated with body composition and smoking.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Body Composition*
  • Educational Status
  • Female
  • Gravidity
  • Humans
  • Maternal Age
  • Middle Aged
  • Netherlands / epidemiology
  • Pregnancy
  • Pregnancy Complications / epidemiology*
  • Prevalence
  • Registries
  • Retrospective Studies
  • Risk Factors
  • Smoking / epidemiology*
  • Twins, Dizygotic*
  • Twins, Monozygotic
  • Young Adult