Determinants of preterm birth in public hospitals in central Ethiopia: an unmatched case-control study

Background : Around 15 million babies are born prematurely in the world every year. The most common cause of neonatal death in Ethiopia is premature birth. To reduce the rate of preterm delivery by correcting modifiable or preventable causes, the availability of local data is important. Hence, this study aimed to identify the determinants of preterm birth among women who gave birth in public hospitals in central Ethiopia. Methods: An Institutional-based unmatched case-control study was conducted at public hospitals in central Ethiopia to select 170 cases and 340 controls. The collected data were entered into EPI INFO and transferred to SPSS for analysis. Tables, graphs, and proportions were used to present the results. Binary and multiple logistic regressions analysis were computed to identify determinants of preterm birth. Adjusted Odds Ratio (AOR), 95% Confidence Interval (CI), and a p-value < 0.05 were computed to determine the presence of an association between preterm birth and independent variables. Results : A total of 166 cases and 332 controls participated in the study, giving a response rate of 97.6%. Cigarette smoking (AOR=3.77, 95% CI=1.35,10.56), alcohol consumption (AOR=1.85, 95% CI=1.11,3.10), wanted but unplanned pregnancy (AOR=3,95% CI=1.68,5.34), neither wanted nor planned pregnancy(AOR=3.61% CI=1.62,8.06), lack of antenatal care (ANC) visits (AOR=4.13, 95% CI=1.95, 8.74), adverse birth outcomes (AOR=5.66, 95% CI=2.88,11.12), presence of a diagnosed illness (AOR=2.81, 95% CI=1.37, 5.76), presence of one or more of obstetrics complications(AOR=6.44, 95% CI=5.49, 3.35, 9), and hemoglobin level < 11g/dl  (AOR=2.78, 95% CI=1.48, 5.22) were determinants of preterm birth. Conclusion:- In this study, cigarette smoking status, alcohol drinking status, pregnancy status, adverse birth outcomes, ANC visits, obstetric complications,  presence of medical illness, and anemia were identified as determinants of preterm birth. It is important to encourage such women to attend ANC visits, stop smoking, and abstain from alcohol.