[Risk factors for recurrent preterm delivery in three university hospitals]

ABSTRACT

Preterm labor is defined as delivery before 37 weeks of gestation. Recurrence of preterm labor in future pregnancies is 6-8%. History of preterm labor is a strong risk factor for future preterm labor. Preterm labor is the leading cause of neonatal mortality in developed countries, but permanent morbidity in these premature neonates has many side effects for the newborn as well as their family members and society. For this reason we conducted a survey to identify risk factors for recurrent preterm delivery among primiparous women with previous preterm delivery. This prospective case-control study included patients from three university hospitals, namely Imam Khomeini, Shariati and Mirza Koochakkhan Hospitals, all in Tehran, Iran. Subjects, including 539 primiparous women who delivered preterm [22-36 weeks], were divided into two groups 47 had a second preterm delivery [study group] and 492 had first preterm delivery [control group]. Exclusion criteria were induced preterm delivery due to medical indications in mother and primigravid. Data collection and analysis was performed using SPSS 10 and t-test and chi[2] test were used to analyze the significance of the results. From a total of 6,537 deliveries, we found 539 cases of preterm delivery, among which 47 cases were identified as recurrent preterm delivery. The control group was composed of 492 deliveries. The recurrence of preterm delivery was 8.7%. Uterine anomaly, cardiovascular, renal and thyroid disease in mother and blood group A had a significant correlation with recurrent preterm delivery. Expectant mothers with uterine anomalies, cardiovascular, renal or thyroid diseases or group A blood type should receive extra care, observation and instructions in order to limit the risk of preterm delivery and its subsequent effects