Associations Between Potential Listeria monocytogenes Exposure During Pregnancy and Infant Outcomes at Birth and

Kee June Ooi1,2, Sasha Fenton1,2, Rachael Taylor1,2

  • 1School of Health Sciences, College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, New South Wales, Australia, ncl.ac.uk.

Journal of Pregnancy
|August 1, 2026
PubMed

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.

Related Concept Videos

Development of the Oral Microbiota01:28

Development of the Oral Microbiota

The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
Development of Human Microbiota01:30

Development of Human Microbiota

The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...
Teratogenicity01:07

Teratogenicity

The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and the drug producing this effect is known as a teratogen. Teratogenic effects include stillbirth, miscarriage, intrauterine growth restriction, and neurocognitive delay. A teratogen may affect the embryo at different stages of development, which is important in determining the type and extent of the damage. During blastocyst formation, the early...