Maternal multimorbidity and chronic conditions as predictors of preterm birth: A matched case-control study in Cyprus

Preterm birth (PTB) is a leading global cause of neonatal morbidity and mortality. While individual maternal chronic conditions are established risk factors, the role of maternal multimorbidity remains underexplored. This study aimed to examine the association between maternal multimorbidity and PTB, and to identify chronic conditions associated with the occurrence and severity of PTB.

A retrospective matched case-control study was conducted at Archbishop Makarios III Hospital in Nicosia, Cyprus. The sample included 978 singleton live births, consisting of 489 preterm cases (<37 weeks) matched 1:1 with 489 term controls (≥37 weeks) by maternal age and country of origin. Data were extracted from patient's medical records. Multimorbidity was defined as the presence of two or more chronic conditions. Conditional logistic regression assessed associations with PTB, and binary logistic regression examined predictors of extreme/very PTB (<32 weeks) versus moderate/late PTB (32 to <37 weeks).

Maternal multimorbidity was associated with increased odds of PTB (aOR = 1.80; 95% CI: 1.16-2.79; p=0.009). Hypertension (aOR=4.26; 95% CI: 1.84-9.86), kidney disease (aOR=3.67; 95% CI: 1.01-13.30), thrombophilia (aOR=3.53; 95% CI: 1.14-10.88), thyroid disorders (aOR = 1.77; 95% CI: 1.05-2.98), and allergies (aOR=1.82; 95% CI: 1.12-2.99) were independently associated with PTB. Diabetes was inversely associated with extreme PTB (aOR=0.19; 95% CI: 0.10-0.92).

Maternal multimorbidity and several chronic conditions are significant and independent predictors of PTB. These findings underscore the importance of comprehensive antenatal screening and integrated care for women with multiple health conditions. Tailored risk assessment strategies may help reduce the burden of PTB, particularly in populations with rising rates of chronic disease.