Sex ratio and twinning in women with hyperemesis or pre-eclampsia

Epidemiology. 2001 Nov;12(6):747-9. doi: 10.1097/00001648-200111000-00026.


We examined twinning and fetal gender in births of women with a hospital diagnosis of pre-eclampsia or hyperemesis. We also investigated sex ratio in infants whose mothers had had hyperemesis or pre-eclampsia in a different pregnancy. From all the hospitalized cases in Denmark between 1980 and 1996 we extracted 6,227 births with hyperemesis and 24,764 with pre-eclampsia. Twins were more frequent in pregnancies with either condition. The male to female sex ratio was 1.04 (95%CI = 1.02-1.05) in the reference population, 0.87 (95% CI = 0.82-0.91) in births with hyperemesis, and 1.10 (95% CI = 1.07-1.12) in births with pre-eclampsia. Women with pre-eclampsia had slightly more males also in non-affected pregnancies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Denmark / epidemiology
  • Female
  • Humans
  • Hyperemesis Gravidarum / epidemiology*
  • Infant, Newborn
  • Pre-Eclampsia / epidemiology*
  • Pregnancy
  • Sex Ratio*
  • Twins / statistics & numerical data*