Maternal anemia is associated with peripartum, intrapartum, and postpartum complications for the mother, as well as preterm birth for the infant, according to a study published in the Journal of Perinatology.
Researchers used hospital discharge records from between 2007 and 2012 to identify live, singleton births born between 22 and 42 (n=2,869,415) weeks’ gestation. Anemia during pregnancy was defined by the International Classification of Diseases, Ninth Revision, diagnostic code for anemia during a hospital admission during pregnancy or in the delivery hospital discharge record. Three models were used to calculate risk for adverse neonatal outcomes resulting from maternal anemia: maternal characteristics found to differ between women with anemia and women without, model 1 plus obstetric factors found to differ between women with anemia and women without, and model 2 plus gestational age. Additional adverse neonatal outcomes included small or large for gestational age, preterm or early-term birth, and infant death.
A total of 284,780 (9.9%) women in the study were diagnosed with anemia; these women were more likely to be nonwhite (ie, Asian or black), be age ≤34 years, begin obtaining prenatal care after the first trimester of pregnancy, have public insurance, have a high body mass index, use or abuse drugs, smoke, or be nulliparous. More than 10% of women with anemia also had hypertension during pregnancy; these patients were also more likely to experience additional obstetric complications such as diabetes and fibroids. Women with a diagnosis of anemia were also more likely to experience maternal morbidities including blood transfusion, hysterectomy, or admission to the intensive care unit.
Infants born to mothers with anemia were more likely to be large for gestational age. A total of 1.5% of babies born to mothers with anemia were delivered at 32 weeks’ gestation compared with 0.7% of those without anemia. A similar percentage of infants born to mothers with anemia and to mothers without anemia were delivered between 39 and 42 weeks’ gestation (65.6% vs 66.4%), a larger percentage of infants born to mothers with anemia were born preterm (8.9% vs 6.5%), and a smaller percentage were born early term (25.5% vs 27.1%).
“Since anemia is a relatively easy disease to diagnose and treat, we anticipate that this data can help drive studies to examine outcomes of maternal anemia prevention interventions,” the authors concluded.
Beckert RH, Baer RJ, Anderson JG, Jelliffe-Pawlowski LL, Rogers EE. Maternal anemia and pregnancy outcomes: a population-based study [published online April 9, 2019]. J Perinatol. doi:10.1038/s41372-019-0375-0