Gynecology & Obstetrics
Open Access

Abstract

Risk Factors for Late Preterm Births: A Case-Control Study

Gian P Mandruzzato, Giuseppe Calì, Francesca Chiaffarino, Giuseppe Dal Pozzo, Luana Danti, Vera Gerosa, Pietro Iacobelli, Carlo Laezza, Francesco Macagno, Fabio Parazzini and Paolo Scollo

Aim: This study examines the influence of selected sociodemographic and pregnancy specific factors on the risk of Late Preterm Births (LPB) analyzing separately induced and spontaneous.

Methods: We conducted a case-control study of LPB observed in 5 Italian Centers. Cases are 305 women who delivered at 34, 35 and 36 weeks gestation. The controls were 269 women who gave birth at term (>37 weeks of gestation).

Results: Considering the total series, the risk of LPB was above unity in hypertensive women, but the OR was 6.70 (95% CI 3.25-13.82) in women with induced LPB and 0.90 (95% CI 0.35-2.32) in women with spontaneous LPB. Positive culture of vaginal smear was associated with an increased risk of LPB.

Conclusions: According to our results hypertension increases the risk of medically indicated LPB while a history of preterm birth or positive vaginal smear are associated with an increased risk of spontaneous and induces LPB.