Pulmonary Morbidity in Infancy after Exposure to Chorioamnionitis in Late Preterm Infants

Abstract

Rationale: Chorioamnionitis is an important cause of preterm birth, but its impact on postnatal outcomes is understudied.Objectives: To evaluate whether fetal exposure to inflammation is associated with adverse pulmonary outcomes at 6 to 12 months' chronological age in infants born moderate to late preterm. Methods:Infants born between 32 and 36 weeks' gestational age were prospectively recruited (N = 184). Chorioamnionitis was diagnosed by placenta and umbilical cord histology. Select cytokines were measured in samples of cord blood. Validated pulmonary questionnaires were administered (n = 184), and infant pulmonary function testing was performed (n = 69) between 6 and 12 months' chronological age by the raised volume rapid thoracoabdominal compression technique. Measurements and Main Results:A total of 25% of participants had chorioamnionitis. Although infant pulmonary function testing variables were lower in infants born preterm compared with historical normative data for term infants, there were no differences between infants with chorioamnionitis (n = 20) and those without (n = 49). Boys and black infants had lower infant pulmonary function testing measurements than girls and white infants, respectively. Chorioamnionitis exposure was associated independently with wheeze (odds ratio [OR], 2.08) and respiratory-related physician visits (OR, 3.18) in the first year of life. Infants exposed to severe chorioamnionitis had increased levels of cord blood IL-6 and greater pulmonary morbidity at age 6 to 12 months than those exposed to mild chorioamnionitis. Elevated IL-6 was associated with significantly more respiratory problems (OR, 3.23).Conclusions: In infants born moderate or late preterm, elevated cord blood IL-6 and exposure to histologically identified chorioamnionitis was associated with respiratory morbidity during infancy without significant changes in infant pulmonary function testing measurements. Black compared with white and boy compared with girl infants had lower infant pulmonary function testing measurements and worse pulmonary outcomes.

Early Life Wildfire Smoke Exposure Is Associated with Immune Dysregulation and Lung Function Decrements in Adolescence

“…Our finding of increased weight trajectory in wildfire smoke-exposed females also suggests that metabolic processes are affected by air pollutants. Sex differences in lung measurements are dependent upon age, with males showing lower pulmonary function relative to females in the postnatal period, but increasing function relative to females in adolescence (46,47). The animals in our study were approximately 3 years old at the time of evaluation, which is onset of puberty in males and after onset of puberty in females.…”

Association of Chorioamnionitis with Aberrant Neonatal Gut Colonization and Adverse Clinical Outcomes

“…During chorioamnionitis, inflammatory cells of maternal origin infiltrate fetal membranes[ 16 ]. Furthermore, increases in cord blood cytokines are largely restricted to funisitis cases, and chorioamnionitis is more severe when funisitis is also present [ 30 , 31 ]. We then used a 3-way comparison between the study groups NC, AC and ACF, setting comparison criteria as one against all using a p-value of 0.05, and a minimum linear discriminant analysis (LDA) score of 2.0.…”

Pulmonary IL-1β expression in early life causes permanent changes in lung structure and function in adulthood

“…Late preterm infants (defined by a gestational age of 34 -36 ϩ 6 wk) are often exposed to antenatal inflammation; acute and chronic chorioamnionitis have an incidence of 13% and 27% in late preterm births, respectively (27). In a recent study, a history of chorioamnionitis in late preterm infants correlated with respiratory morbidity in infancy (29). Oxygen therapy for respiratory diseases such as pneumonia, transient tachypnea of the neonate, or mild respiratory distress syndrome may also lead to pulmonary inflammation in these infants.…”

“…The mammalian lung undergoes five distinct developmental stages: the embryonic [3-7 gestational weeks (GW) in humans and embryonic day (E) 9.5-14 in mice], pseudoglandular (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) GW in humans and E14 -16.5 in mice), canalicular (16 -26 GW in humans and E16.5-17.5 in mice), saccular [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] in humans and E17.5-postnatal day (PN) 5 in mice], and alveolar stages (from 36 GW to early childhood in humans and PN5-30 in mice) (34).…”