A relationship between a level of hemoglobin after delivery and exclusive breastfeeding initiation at a baby friendly hospital in Japan

The recent National Nutrition Survey of 2013 demonstrated that 16.7% of women in childbearing age are underweight, and 5.0–10.0% of these women manifested a Hemoglobin (Hb) level less than 11.0 g/dl. The purpose of this study was to investigate if such maternal nutritional status affects success of exclusive breastfeeding (EBF) practice.

This cross-sectional study investigated 1532 dyads of mothers and infants with full-term singleton pregnancies delivered during 2011 at a perinatal center in Tokyo. Outcome is EBF initiation defined as the successful practice at discharge and 1 month after discharge. A logistic regression model was applied to investigate the impact of Hb levels (<9.0, 9.0–10.9, and ≥11.0 g/dl) measured within 2–3 days after delivery on successful EBF initiation adjusting for covariates including bleeding at delivery.

Mean age was 34 years, 23.0% were underweight and 63.0% were nulliparous. The success rate for EBF initiation at discharge and at 1 month after discharge was 72.7 and 63.0% for a Hb level <9.0 g/dl, 81.9 and 68.9% for a Hb level of 9.0–10.9 g/dl, and 85.7 and 75.9% for a Hb level ≥11.0 g/dl, respectively. A logistic regression model showed that risk factors of unsuccessful EBF practice at discharge and 1 month after discharge included lower level Hb categories (P < 0.001 and P < 0.001), postpartum hemorrhage > 500 ml (P = 0.089 and P = 0.011), maternal age (P < 0.001 and P < 0.001), nulliparity (P < 0.0001 and P < 0.001), pregnancy-induced hypertension (P = 0.002 and P = 0.012), gestational week (P = 0.006 and P = 0.002), Low Birth Weight (LBW) (P < 0.001 and P < 0.001), and immediate separation (P < 0.001 and P = 0.020). After adjusting for the covariates, compared with a Hb level ≥11.0 g/dl, a Hb level <9.0 g/dl was significantly associated with unsuccessful EBF initiation at discharge [odds ratio (OR): 2.15; 95% confidence interval (CI): 1.37–3.39] and at 1 month after discharge (OR: 1.63; 95% CI: 1.10–2.42), and a Hb level of 9.0–10.9 g/dl also was significant at 1 month after discharge (OR: 1.35; 95% CI: 1.04–1.75). Pre-pregnancy underweight was not associated with success of EBF practice both at hospital discharge and 1 month after discharge.

Maternal severe anemia after delivery was associated with the risk of unsuccessful initiation of EBF even after adjusting for bleeding at delivery, suggesting the importance of dietary management especially in the later trimester.