Occupational working conditions as risk factors for preterm birth in Benin, West Africa

Although many studies from developed countries have established a relationship between various occupational working conditions during pregnancy and preterm birth, there is little data available in developing countries where both maternal physical labor during pregnancy and preterm birth are common. The aim of this study was to examine the association between difficult occupational working conditions of pregnant women and premature births in the Republic of Benin in West Africa.

The case-control study included 99 women with preterm babies and 104 women with full-term babies. The participants were residents of the Republic of Benin who delivered between May 1, 2000 and April 30, 2002. Preterm delivery was defined as delivery prior to 37 completed weeks of gestation. The study sample was selected randomly from birth records. Data were collected both reviewing birth records and conducting semi-structured personal interviews with mothers. Logistic regression models were adjusted for mother's age, mother's education, health problems during pregnancy, and twin birth.

Although working state of mother during pregnancy did not increase the risk for preterm delivery, carrying heavy loads more than 5 days per week was significantly associated with having a preterm baby (adjusted OR: 5.0; 95% CI: 1.38-18.8; P=0.018). Carrying heavy loads and having worked a lot more than 5 days per week was also significantly associated with preterm birth (adjusted OR: 6.88; 95% CI: 1.45-32.2; P=0.015).

Reducing heavy loads carrying during pregnancy may also prevent preterm delivery in developing countries. Though replication of these data using a prospective design is needed, our results suggest that educating women about the risks associated with heavy labor during pregnancy is indicated.