Meconium stained amniotic fluid exposure and long‐term respiratory morbidity in the offspring

Abstract

Objective Meconium stained amniotic fluid (MSAF) is a well‐established risk factor for neonatal short‐term respiratory complications. Little is known regarding the long‐term morbidity. We investigated the possible association between MSAF and offspring respiratory morbidity. Methods A population‐based, cohort study of singleton deliveries occurring between 1991 and 2014 at a sole regional tertiary medical center was performed. Incidence of offspring respiratory related hospitalizations up to the age of 18 years were evaluated and compared to unexposed offspring. A Kaplan–Meier survival curve was used to compare cumulative respiratory morbidity incidence, and a Cox proportional hazards model was used to control for confounders. Results During the study period 242,342 deliveries met the inclusion criteria. Of them, 14.7% (n = 35,609) were complicated with MSAF. Incidence of respiratory‐related hospitalizations was significantly lower in children exposed to MSAF as compared to the unexposed group (4.5% vs. 4.9%, respectively; p < .01). Specifically, hospitalizations involving pneumonitis were significantly less common among the MSAF group (odds ratio, 0.35; 95% confidence interval [95% CI], 0.13–0.96; p = .03). The Kaplan–Meier survival curve demonstrated significantly lower total cumulative respiratory morbidity rates in the MSAF exposed group (log rank p < .01). In the Cox model, controlled for clinically relevant confounders, MSAF exhibited an independent and significant protective effect on long‐term childhood respiratory morbidity (aHR, 0.91; 95% CI, 0.86–0.96; p < .01). Conclusions Fetal exposure to MSAF during labor appears to be associated with lower rates of long‐term respiratory related hospitalizations in the offspring. Changes in offspring microbiome, as well as functional and anatomical modulations possibly resulting from MSAF exposure, might offer a plausible explanation of our findings.

Once We Find Grade III Meconium Stained Amniotic Fluid, Must We Act as Early as Possible?

“…Two large studies reported that the incidence was approximately 14.7% (35,897/243,725; 35,609/242,342). 4 , 5 Before 37 weeks, MSAF was less common, occurring in approximately 4.3–6.9% of pregnancies, but with increasing gestation week, a higher incidence of MSAF was observed, in approximately 10.0–14.6% of pregnancies (listed in Table S1 ), 6 which was in accordance with previous studies showing that MSAF most commonly occurred from 38–41 weeks of gestation. 7 …”

“…Two large studies reported that the incidence was approximately 14.7% (35,897/243,725; 35,609/242,342). 4,5 Before 37 weeks, MSAF was less common, occurring in approximately 4.3-6.9% of pregnancies, but with increasing gestation week, a higher incidence of MSAF was observed, in approximately 10.0-14.6% of pregnancies (listed in Table S1), 6 which was in accordance with previous studies showing that MSAF most commonly occurred from 38-41 weeks of gestation. 7 According to the standard grading system for meconium, MSAF can be classified into 3 grades: I (translucent, light green or yellow flesh), II (opalescent, deep green and light yellow, brown), and III (opaque and deep green), and it can also be classified as thin or thick based on the different solid contents.…”

“…25 In addition to the abovementioned short-term neonatal outcomes, recent studies have followed up on the long-term outcome in newborns. Fetal exposure to MSAF during labor and delivery may result in lower rates of long-term infectious-related hospitalizations, lower incidence of long-term infectious morbidity in the offspring, 4 lower rates of long-term respiratory-related hospitalizations, 5 and an independent protective factor for dermatitis and skin rash-related hospitalizations throughout childhood and adolescence. 22,26 It seems that MSAF may affect newborns more than women, but newborns also benefit from the long-term effects of MSAF.…”