Maternal history of recurrent pregnancy loss increases the risk for long-term pediatric respiratory morbidity of the offspring

Background: While the etiology in many cases of recurrent pregnancy loss (RPL) is unclear, recent evidence suggests possible immunological dysfunction, which is also implicated in the pathophysiology of many pediatric respiratory diseases. Objective: We sought to investigate whether maternal history of RPL is associated with long-term respiratory morbidity of the offspring. Study Design: A population based cohort analysis was performed comparing the risk of long-term respiratory morbidity (up to the age of 18 years) of children born to mothers with and without a history of RPL (defined as two or more losses). Respiratory morbidity included hospitalizations involving a predefined set of ICD-9 codes, as recorded in the hospital medical records. Deliveries occurred between the years 1991 and 2014 in a tertiary medical center. A Kaplan-Meier survival curve was constructed to compare cumulative respiratory morbidity, and a Cox proportional hazards model was used to control for confounders. Results: During the study period, 242 187 newborns met the inclusion criteria; 5% (n = 12 182) of which were offspring to mothers with a history of RPL. Respiratory morbidity was significantly more common in the exposed group (6.0% vs 4.8%, P <.001). Specifically, offspring to mothers with a history of RPL had higher rates of obstructive sleep apnea and asthma (P <.05). The Kaplan-Meier survival curve exhibited a higher cumulative incidence of total respiratory morbidity in offspring of mothers with a history of RPL (Log rank P <.001). In the Cox regression, maternal history of RPL was independently associated with increased pediatric respiratory morbidity of the offspring with an adjusted hazard ratio of 1.24 (95 % confidence interval [95%CI], 1.15-1.34, P <.001). Conclusion: Maternal history of RPL is associated with a higher risk of future pediatric respiratory morbidity of the offspring; possibly explained by a common immunological etiology.