Associations Between Potential Listeria monocytogenes Exposure During Pregnancy and Infant Outcomes at Birth and Infant Delivery Resource Use: A Cross-Sectional Analysis in Australian Women.

Pregnant women are at higher risk of contracting listeriosis, which can lead to serious perinatal complications. This study evaluated associations between Listeria monocytogenes exposure, infant perinatal outcomes, and hospital resource use in a cohort of 1604 Australian mother-infant dyads. Maternal L. monocytogenes exposure was estimated from self-reported intake of foods from a validated food frequency questionnaire that potentially harbor L. monocytogenes. Infant outcomes obtained from hospital medical records included birth mode, preterm birth, birthweight, and admission to special care nursery (SCN)/neonatal intensive care unit (NICU). Infant hospital resource use was measured by infant length of stay (LOS), LOS in SCN/NICU, and days excluding SCN/NICU. Multinomial, negative binomial, and hurdle models, were performed to examine Listeria Food Exposure Score (LFES) associations with infant outcomes, total LOS, and LOS excluding and within SCN/NICU. All models were adjusted for covariates including smoking, parity, maternal age, BMI, and SEIFA IRSAD decile. Mean (SD) maternal age was 32.0 (5.0) years, and median (IQR) gestation was 39.0 (38.1, 40.0) weeks. Although adjusted results showed a statistically significant association between LFES and reduced infant LOS excluding SCN/NICU (β = 0.99; 95% CI: 0.979, 0.998, p < 0.03), the effect size was minimal, with minor clinical significance. There were no significant associations with infant birth mode, preterm birth, low birthweight, size for gestational age, macrosomia, admission to NICU/SCN, total LOS in hospital, and SCN/NICU (all p > 0.05). Future research should explore these associations among ethnically diverse women at earlier stage of pregnancy and include the assessment of food safety practices in the analyses.