Sociodemographic, behavioral, and obstetric factors associated with preterm birth and its severity: A matched case-control study in Cyprus.

INTRODUCTION

Preterm birth (PTB), defined as delivery before 37 weeks of gestation, is a major cause of neonatal mortality and morbidity worldwide. Its multifactorial etiology remains incompletely understood, and Cyprus reports among the highest PTB rates in Europe, highlighting the need for population-specific evidence. This study aimed to investigate the sociodemographic, behavioral, and obstetric history factors of PTB in Cyprus and to examine whether these factors differed according to the degree of prematurity.

METHODS

A matched case-control study was conducted at a tertiary referral hospital in Cyprus, designated as the national center for maternal and neonatal care. Eligible participants were women delivering between January 2019 and December 2022. Conditional logistic regression was conducted to determine the significant associations between sociodemographic, behavioral and obstetric history with PTB. Subgroup analysis of extreme to very (<32 weeks) vs moderate to late PTB (32 to <37 weeks) was also conducted.

RESULTS

Participants were 978 women (489 cases <37 weeks, 489 controls ≥37 weeks). Maternal age increased PTB odds (AOR=1.21; 95% CI: 1.06-1.38), as did previous gynecological surgeries (AOR=1.74; 95% CI: 1.30-2.34), cesarean section (AOR=1.87; 95% CI: 1.28-2.73), and miscarriage (AOR=1.44; 95% CI: 1.03-2.00). Primiparous women had reduced odds versus nulliparous (AOR=0.71; 95% CI: 0.52-0.98). In subgroup analysis, higher BMI (AOR=0.96; 95% CI: 0.92-0.99), prior cesarean (AOR=0.54; 95% CI: 0.30-0.99), and asylum seeker status (AOR=0.19; 95% CI: 0.05-0.67) were linked to lower odds of extreme PTB.

CONCLUSIONS

Future prospective studies are needed to further investigate and confirm the observed associations between sociodemographic, behavioral, and obstetric factors with PTB and degree of prematurity.