Maternal hypothyroidism and the risk for future gastrointestinal morbidities of the offspring

Objective
Maternal hypothyroidism may impact imprinting during intrauterine development. Hence, exposure may be associated with increased risk of future morbidity in the offspring. We aimed to assess whether exposure to hypothyroidism during pregnancy increases the risk for long-term gastrointestinal (GI) morbidity in the offspring.

Study Design
A retrospective population-based cohort study compared long-term gastrointestinal morbidity of offspring following pregnancies exposed and unexposed to maternal hypothyroidism. Deliveries occurred in a regional tertiary medical center between the years 1991-2014. Congenital malformations were excluded from the study. A survival curve and a Cox multivariate model were used to assess the association.

Results
During the study period 217,910 deliveries met the inclusion criteria; 1.1% of deliveries were in parturients diagnosed with hypothyroidism (n=2403). The survival curve indicated that children exposed in-utero to hypothyroidism had a higher cumulative incidence of long-term GI related hospitalizations (Figure). In the Cox proportional hazards model, adjusted for multiple confounders, maternal hypothyroidism during pregnancy remained independently associated with an increased risk for gastrointestinal related hospitalizations in the offspring (Table).

Conclusion
Maternal hypothyroidism during pregnancy appears to be a significant risk factor for long-term pediatric gastrointestinal morbidity in the offspring.