Objective: To describe patterns of vaginal bleeding in the first 20 weeks of pregnancy and evaluate the association between patterns of bleeding and risk of subsequent pre-eclampsia in nulliparous women.
Design: Cohort study.
Setting: Participating centres of the Screening for Pregnancy Endpoints (SCOPE) study in Auckland (New Zealand), Adelaide (Australia), Manchester and London (UK) and Cork (Ireland).
Population: Healthy nulliparous women (n= 3431).
Methods: Logistic regression was used to assess the association between bleeding characteristics and pre-eclampsia while controlling for known determinants of pre-eclampsia.
Main outcome measures: Preeclampsia, defined as gestational hypertension with proteinuria or any multi-system complication of preeclampsia. Four bleeding variables were evaluated: any bleeding during the first 20 weeks; maximal bleeding intensity; duration of bleeding; and number of bleeding episodes.
Results: Of the 3431 women enrolled, 780 (23%) experienced vaginal bleeding during the first 20 weeks of pregnancy. Risk of pre-eclampsia was not associated with the presence or absence of bleeding (adjusted odds ratio (ORa) 0.96, 95% confidence interval (95% CI) 0.67-1.38). Analyses confined to women with vaginal bleeding showed that any bleeding episode of five or more consecutive days, compared with shorter episodes, increased risk of pre-eclampsia approximately twofold (ORa 2.15, 95% CI 1.01-4.57), as did multiple compared with single episodes of bleeding (ORa 2.33, 95% CI 1.16-4.67).
Conclusions: Bleeding is a common complication during the first 20 weeks of nulliparous pregnancy, and the presence or absence of vaginal bleeding is not a determinant of subsequent pre-eclampsia. Among women with vaginal bleeding, consideration of the bleeding pattern, in terms of intensity, duration and frequency, appears to be informative with respect to pre-eclampsia risk.
© 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.