Maternal obesity as a risk factor for very pre-term delivery in dichorionic twin pregnancies.

We attempt here to identify the maternal characteristic factors most strongly associated with the increased risk of very pre-term delivery in dichorionic twin deliveries. Data were collected from 24 dichorionic twin pregnancies who were born at <32 weeks' gestation (very pre-term delivery) and 245 dichorionic twin pregnancies, who were born at 37-40 weeks' gestation as controls. Data included maternal age, height, body weight, body mass index (BMI), history of abortion, parity, maternal smoking, history of infertility therapy, such as in vitro fertilisation and/or embryo reduction, chronic hypertension and diabetes mellitus. Using logistic regression, the risk of very pre-term delivery was significantly increased among obese women (BMI >or=30 during prepregnancy; the adjusted odds ratio: 5.1, 95% confidence intervals: 1.2-21, p = 0.01). The current results indicate that maternal obesity is an independent risk factor for very pre-term delivery in dichorionic twin pregnancies.