A study of the epidemiology of preterm labor

A case-control study was designed in order to identify risk factors associated with preterm labor. All cases fulfilling the criteria of eligibility as preterm labor and attending the Ain Shams University Maternity Hospital during the period from January 1991 to June 1991 were included in the study. In the meanwhile, all women delivering after the 37th week of gestation during that period and in the same hospital and matched according to age (+/- 5 years) were included as the control group. Two hundred and thirty four cases and 216 controls were included in the study. An interview was performed to fill an epidemiologic and clinical questionnaire. Results showed that the lower the socioeconomic standard, the more the risk for preterm labor (p < 0.05), smoking whether active or passive is associated with preterm labor (p < 0.001), threatened or induced abortion, unwanted pregnancy, psychological trauma and surgical intervention during current pregnancy are associated with preterm labor (p < 0.001). History of preterm labor is associated with the present condition (p < 0.001). Anemia, hypertension, body weight less than 70 kgm are associated with preterm labor (p < 0.001).