The association of first trimester bleeding with preterm delivery.

Introduction: Preterm birth (PTB) is a predictor of perinatal morbidity and mortality, and prematurity continues to burden public healthcare with growing expenses. First trimester bleeding (FTB) has a well-known association with PTB; however, the relationship with severity of PTB is less obvious.

Aim: The primary aim of the study was to analyze the influence of FTB on the risk and severity of PTB, as well as to assess the connection of FTB and other pregnancy complications.

Methods: It was an observational case control study. The material consisted of medical records of patients who delivered between 2010 and 2013. Two groups were formed - 497 women with FTB and 500 women without bleeding.

Results: Women with FTB were more likely to deliver preterm in general (OR=2.11; 95% CI 1.43-3.10). The risk of extremely PTB (<28 weeks) was almost four-fold (OR=3.76; 95% CI 0.97-17.06) and very PTB (28-31 weeks) more than three-fold (OR=3.41; 95% CI 0.86-15.69). FTB increased the risk of placenta previa (OR=4.81; 95% CI 1.29-20.53; P=0.007).

Conclusion: FTB is a risk factor of PTB and is associated with greater risk of PTB-related pregnancy complications. Management of FTB pregnancies should include thorough screening for both preterm delivery and placental pathologies.