The postpartum docosahexaenoic acid status of lactating and nonlactating mothers.

Abstract

Results of a cross-sectional study conducted by A1 et al. (1) indicate that the maternal docosahexaenoic acid (DHA) levels in plasma phospholipids are lower with each following pregnancy. This suggests that mothers invest DHA in the development of their infants, possibly by mobilization of their own DHA stores. This view is supported by another observation of A1 et al. (2) that the amount of DHA in the maternal plasma phospholipids increases by more than 30% during pregnancy. Since breast milk contains DHA, breast-feeding, in contrast to bottle-feeding, may continue to impose on the maternal DHA after delivery. Therefore, we compared the recovery of the maternal DHA postpartum between lactating and nonlactating mothers. Methods. Healthy pregnant women in their last trimester were recruited through midwives in the area of Southern Limburg. A written inform consent was obtained from each participant before the start of the study, which was approved by the Medical Ethics Committee of the University Hospital Maastricht. Subjects were excluded if they received a blood transfusion at delivery. Blood samples were collected into EDTA-containing tubes at week 36 of pregnancy, on the 2nd and 5th day after delivery, and at 1, 2, 4, 8, ! 6, 32, and 64 wk postpartum. Fatty acids were analyzed in plasma phospholipids as described previously (2). The DHA levels of the two groups were compared using multiple regression analysis, with correction for parity. Results and conclusion. The preliminary results until 16 wk postpartum of 17 lactating mothers aged 33. l + 0.6 yr and 10 nonlactating mothers aged 30.0 +_ 1.1 yr are reported. Both the lactating and the nonlactating mothers had uncomplicated pregnancies and delivered full-term singleton newborns (39.8 + 0.2 vs. 39.9 + 0.4 wk, respectively). At week 16, the mothers in the lactating group were still breast-feeding their infants. There were no differences in the DHA levels of the two groups shortly after delivery (on the 2nd and the 5th day postpartum). The DHA levels started to decrease in both groups from week 1 postpartum. This decline became more pronounced in the lactating group, and at weeks 8 and 16 the DHA levels of the lactating mothers were significantly lower than those of the nonlactating mothers. A comparison of the DHA levels at weeks 8 and 16 with data of 80 nonpregnant women showed that the levels of the lactating mothers were significantly lower than those of the nonpregnant women, whereas the levels of the nonlactating mothers were quite comparable with the nonpregnant group. It can be concluded that maternal plasma DHA declines after delivery. This reduction is more pronounced in lactating as compared to nonlactating mothers. The DHA levels of lactating mothers reach values lower than in nonpregnant women. This observation suggests that lactating mothers may become DHA-depleted unless they increase their DHA intake during lactation. REFERENCES