Idan Alcalay

and 2 more

Objective: To evaluate the association between prenatal maternal anemia (hemoglobin, Hb<11 g/dl) and long-term respiratory morbidity of the offspring. Methods: A retrospective population-based cohort analysis was performed at the Soroka University Medical Center (SUMC), a single regional tertiary medical center. All singletons born between the years 1991-2014 and discharged alive were included in the study. Offspring with congenital malformations were excluded. The three study groups were defined based on maternal Hb levels, measured upon postpartum discharge: <7.0 (severe anemia), 7.0-11.0 (mild to moderate anemia), and ≥11.0 g/dl (unexposed). Respiratory morbidity diagnosis was based on predefined ICD-9 codes of lung disease definitions, based on the medical records of the hospitalized offspring in SUMC. A Kaplan-Meier survival curve was formed to compare the cumulative respiratory morbidity during the study follow-up period between the study groups, and a multivariable Cox survival analysis was used to control for cofounders. Results: During the study period, 214,305 deliveries met the inclusion criteria. Of those, 807 (0.3%) mothers had severe anemia, 105,196 (49.1%) mothers had mild-moderate anemia, and the remaining were not anemic (108,302, 50.5%). Respiratory hospitalization incidence was found to be significantly higher among the offspring born to anemic mothers (6.2%; 5.3% and 5.1%; p = 0.020, p for trend=0.007 in severe, mild-to-moderate and non-anemic mothers, respectively). The association between maternal anemia and respiratory-related hospitalization of the offspring remained significant among the mild-moderate anemic group after adjusting for confounders in the Cox proportional hazards model (adjusted hazard ratio=1.1; 95% CI 1.05-1.14; p < 0.01). As to the association between severe maternal anemia and offspring morbidity no significant differences were found (p= 0.133), although a linear hazard dose-response ratio was found between the mild-moderate and severe anemic groups (aHR=1.09, aHR 1.24, respectively). Conclusion: Maternal anemia was found to be associated with long-term respiratory morbidity of the offspring.