Sociodemographic and Obstetric Predictors of Preterm Birth in Cyprus: A Case–Control Study

Background

Preterm birth (PTB), defined as delivery prior to 37 weeks of gestation, remains a leading cause of neonatal mortality and morbidity globally. Despite its significance, its multifactorial causes are not yet fully understood. Cyprus has one of the highest PTB rates in Europe, highlighting the need of context-specific evidence.

Methods

A matched case–control study was conducted at a tertiary referral hospital in Cyprus, the national centre for maternal and neonatal care. Women who gave birth between January 2019 and December 2022 were included. Conditional logistic regression was used to assess associations between sociodemographic, behavioural, and obstetric factors and the risk of PTB. Subgroup analyses compared extreme to very preterm births (<32 weeks) with moderate to late preterm births (32 to < 37 weeks).

Results

The study included 978 women (489 cases <37 weeks; 489 controls >37 weeks). Increasing maternal age was associated with higher odds of PTB (aOR=1.210; 95% CI: 1.059–1.382; p = 0.005), along with a history of gynecological surgery (aOR=1.743; 95% CI: 1.301–2.336; p < 0.001), Cesarean delivery (aOR=1.870; 95% CI: 1.282–2.728; p = 0.001), and prior miscarriage (aOR=1.437; 95% CI: 1.034–1.997; p = 0.031). In contrast, primiparous women had lower odds of PTB compared to nulliparous women (aOR=0.714; 95% CI: 0.518–0.984; p = 0.039). Subgroup analysis showed that higher body mass index (BMI) (aOR=0.959; 95% CI: 0.922–0.997; p = 0.036), previous Cesarean section (aOR=0.540; 95% CI: 0.296–0.985; p = 0.044), and asylum seeker status (aOR=0.186; 95% CI: 0.051–0.673; p = 0.010) were associated with reduced odds of extreme PTB.

Conclusions

Advanced maternal age and adverse obstetric history were associated with increased odds of PTB. Higher BMI, previous Cesarean delivery, and asylum-seeking status were linked to lower odds of extreme prematurity, emphasizing the role of antenatal risk assessment and prevention.

Key messages

• In a high-PTB setting like Cyprus, maternal age and adverse obstetric history are key modifiable risk markers for targeted antenatal intervention.

• Differing predictors of extreme vs. moderate PTB highlight the need for stratified, nurse-led public health strategies to reduce prematurity and improve neonatal outcomes.