A Hospital Based Case-Control Study for the Effects of Maternal Anemia on the Preterm Birth andAdverse Pregnancy Outcomes

Koh, Kyung Sim; Lee, Chang Ik; Oh, Hyung Yang; Chang, Yuk Tsai; Hur, Eui Jong; Park, Jin Wan; Lee, Won Ki; Park, Choong Hak

Abstract

OBJECTIVE
Maternal anemia is one of the most common hematologic disorders of the child-bearingmothers. However the role of maternal anemia in the etiology of preterm delivery and adverse pregnancyoutcomes remains a source of controversy. The aim of this study was to determine the effects of maternalanemia on the preterm birth and the adverse pregnancy outcomes. STUDY DESIGN: A total of 1,010 women aged 19~44 years, who admitted to our hospitalfor the delivery between December 1994 and October 1995, were recruited into a hospitalbaed case-control study design. 259 women complicated by maternal anemia(cases) werecompared with 751 women without maternal anemia(controls). Multiple logistic regressionanalyses were performed to control for the effects of other potentially confounding factors,including maternal age, body mass index, previous term delivery, previous preterm deliveryand previous abortion. In all logistic regression analyses odds ratio and 95% confidenceintervals were calculated.
RESULTS
The prevalence of maternal anemia(hemoglobin<10g/dl) was 25.6%. Therewas a positive linear relationship between the prepartum hemoglobin concentration and thepostpartum concentration. There was no significant differences of the incidence of pretermbirth and the neonatal morbidity, such as poor Apgar scores, fetal distress, congenitalanomaly, birth trauma, admission to neonatal intensive care unit, resuscitation and sepsisbetween case and control groups. Small for gestational age and low birth weight were associatedwith an somewhat decreased risk of maternal anemia and large for gestational age, notmacrosomia, was associated with an 70% increased risk of maternal anemia at the time ofdelivery. Maternal anemia was associated with 6.5 fold increases in the risks of postpartumbleeding, 8.5 fold increases in the postpartum transfusion and 80% increases in the puerperalfever respectively.
CONCLUSIONS
Maternal anemia was not associated with increased risks of preterm birthand the neonatal morbidty. However there was a significant relationship between maternalanemia and postpartum maternal morbidity, such as postpartum bleeding, postpartum transfusionand puerperal fever.