First trimester vaginal bleeding and adverse pregnancy outcomes among Chinese women: from a large cohort study in China

Abstract

Objectives: To examine the effect of first trimester vaginal bleeding on adverse pregnancy outcomes including preterm delivery, low birth weight and small for gestational age. Methods: This is a prospective population-based cohort study. A questionnaire survey was conducted on 4342 singleton pregnancies by trained doctors. Binary logistic regression was used to estimate risk ratios (RRs) and 95% confidence intervals (95% CI). Results: Vaginal bleeding occurred among 1050 pregnant women, the incidence of vaginal bleeding was 24.2%, 37.4% of whom didn’t see a doctor, 62.6% of whom saw a doctor for vaginal bleeding. Binary logistic regression demonstrated that bleeding with seeing a doctor was significantly associated with preterm birth (RR 1.84, 95% CI 1.25–2.69) and bleeding without seeing a doctor was related to increased of low birth weight (RR 2.52, 95% CI 1.34–4.75) and was 1.97-fold increased of small for gestational age (RR 1.97, 95% CI 1.19–3.25). Conclusions: These results suggest that first trimester vaginal bleeding is an increased risk of low birth weight, preterm delivery and small for gestational age. Find ways to reduce the risk of vaginal bleeding and lower vaginal bleeding rate may be helpful to reduce the incidence of preterm birth, low birth weight and small for gestational age.

Keywords::

• Low birth weight
• pregnancy
• preterm birth
• small for gestational age
• vaginal bleeding

Acknowledgements

The authors give appreciation to all pregnant women who participated in the study and all staff and their colleagues working MCH for help in recruitment, data and blood sample collection.

Declaration of Interest: This research was supported financially by the China National Key Technology Research and Development Program (2006BAI05A03). This work was supported by The National Natural Science Foundation of China (grant numbers, respectively are 81072310, 30901202, and 30901203).