Beyond the uterine environment: Nonhuman primate model to investigate maternal-fetal and neonatal outcomes following chronic intrauterine infection

BACKGROUND: Intrauterine infection is a significant cause of early preterm birth. We have developed a fetal-neonatal model in the rhesus macaque to determine the impact of chronic intrauterine infection with Ureaplasma parvum on early neonatal reflexes and brain development. METHODS: Time-mated, pregnant rhesus macaques were randomized to be inoculated with U. parvum (serovar 1; 10(5)cfu) or control media at ~120 dGA. Neonates were delivered by elective hysterotomy at 135–147 dGA (term=167d) stabilized and cared for in our nonhuman primate neonatal intensive care unit. Neonatal reflex behaviors were assessed from birth and fetal and postnatal brain MRIs were performed. RESULTS: A total of 13 preterm and 5 term macaque infants entered the study. 10 preterm infants survived to 6 months of age. U. parvum infected preterm neonates required more intensive respiratory support than control infants. MRI suggest potential perturbation of brain growth and white matter maturation with exposure to intra-amniotic infection. CONCLUSION: We have demonstrated the feasibility of longitudinal fetal-neonatal studies in the preterm rhesus macaque after chronic intrauterine infection. Future studies will examine long-term neurobehavioral outcomes, cognitive development, neuropathology and in vivo brain imaging to determine the safety of antenatal antibiotic treatment for intrauterine infection.