Effect of Inter-pregnancy Interval on Risk of Spontaneous Preterm Labor

Background: Spontaneous preterm labor, is the onset of labor that occurs before the 37th week of gestation and poses significant health risks for mothers and newborns. Both short (under 18 months) and long (over 59 months) inter-pregnancy intervals can increase risks, highlighting the need for tailored prevention and management strategies .Aims of the study: To assess the influence of interpregnancy intervals on the occurrence of spontaneous preterm labor, providing insights into factors affecting gestational outcomes .Methods: A case-control study was conducted to assess the impact of interpregnancy interval on spontaneous preterm labor risk among women delivering at two Basrah hospitals from the 1st of November 2023 to the 1st of September 2024. It included 140 cases who experienced spontaneous preterm labor and 140 controls, who had full-term deliveries, matched for age, BMI, and parity, with data collected via a structured questionnaire and routine examinations.Results: The study included 280 women. Significant findings included irregular antenatal care in 49.3% of cases versus 28.6% of controls (p = 0.001). Previous complications like preeclampsia (p = 0.035), stillbirth (p = 0.047), and preterm labor (p = 0.001) were higher in cases. The mean inter-pregnancy interval was significantly shorter in cases (10.8 ±2.3) months compared to controls (21.3 ±5.4) months (p < 0.001).Conclusion: Short inter-pregnancy intervals significantly increase the risk of spontaneous preterm labor, while regular antenatal care reduces it; however, sociodemographic factors, gestational diabetes mellitus and parity do not predict preterm labor risk in this population.