Influence of maternal vomiting during early pregnancy on school-age respiratory health.

BACKGROUND

Hyperemesis gravidarum, a clinical entity characterized by severe nausea and excess vomiting, might lead to a suboptimal maternal nutritional status during pregnancy and subsequently to adverse respiratory health in the offspring. The role of common vomiting symptoms on offspring's respiratory health is unclear. We examined the associations of maternal daily vomiting during early pregnancy with childhood respiratory outcomes, and potential explaining factors.

METHODS

This study was embedded in a population-based prospective cohort study from early pregnancy onwards among 4232 mothers and their children. Maternal vomiting during early pregnancy was assessed by a questionnaire. At age 10 years, information on current wheezing and ever asthma was obtained by a questionnaire, and lung function was measured by spirometry at our research center. We used multiple regression analyses to assess the associations of maternal daily vomiting during early pregnancy with childhood respiratory outcomes.

RESULTS

Compared to children from mothers without daily vomiting during early pregnancy, children from mothers with daily vomiting during early pregnancy had a higher forced expiratory flow when 75% of the forced vital capacity (FVC) is exhaled (Z-score difference [95% confidence interval, CI]: 0.13 [0.03, 0.23]), and an increased risk of current wheezing and ever asthma ([odds ratio, OR] [95% CI]: 1.75 [1.10, 2.79] and 1.61 [1.13, 2.31], respectively). These associations were fully explained by sociodemographic factors, but not sex or lifestyle-, infectious-, or growth-related factors. Maternal daily vomiting during early pregnancy was not associated with forced expiratory volume in 1 s (FEV1 ), FVC, and FEV1 /FVC.

CONCLUSION

Only sociodemographic factors explain the associations of maternal daily vomiting during early pregnancy with childhood respiratory outcomes.