Factors associated with preterm, early preterm and late preterm birth in Malawi.

Assessment of risk factors for preterm birth in a population with high incidence of preterm birth and HIV infection.Secondary analysis of data for 2,149 women included in a community based randomized placebo controlled trial for the prevention of preterm birth (APPLe trial (ISRCTN84023116) with gestational age at birth determined through ultrasound measurement in early pregnancy. Multivariate Logistic Regression analyses to obtain models for three outcome variables: all preterm, early preterm, and late preterm birth.No statistical differences were noted for the prevalence of HIV infection (p = 0.30) or syphilis (p = 0.12) between women who delivered preterm versus term. BMI (Adjusted OR 0.91 (0.85-0.97); p = 0.005) and weight gain (Adjusted OR 0.89 (0.82-0.97); p = 0.006) had an independent, protective effect. Previous preterm birth doubled the odds of preterm birth (Adjusted OR 2.13 (1.198-3.80); p = 0.01). Persistent malaria (despite malaria prophylaxis) increased the risk of late preterm birth (Adjusted OR 1.99 (1.05-3.79); p = 0.04). Age <20 (Adjusted OR 1.73 (1.03-2.90); p = 0.04) and anemia (Adjusted OR 1.95 (1.08-3.52); p = 0.03) were associated with early preterm birth (