Effects of age at introduction of complementary foods to breast-fed infants on duration of lactational amenorrhea in Honduran women.
Lactational amenorrhea (LA) is associated with postpartum infertility and is known to be related to breast-feeding frequency and duration, but the exact role of complementary feeding of the infant has not been clearly defined. Data on LA were collected during and after a 2-mo intervention trial in which low-income Honduran women who had breast-fed fully for 4 mo were randomly assigned to one of three groups: continued full breast-feeding until 6 mo (FBF, n = 50), introduction of complementary foods at 4 mo with ad libitum breast-feeding from 4 to 6 mo (SF, n = 47), or introduction of complementary foods at 4 mo with maintenance of baseline breast-feeding frequency from 4 to 6 mo (SF-M, n = 44). Women were followed up until the infant was 12 mo of age, or later if menses had not occurred by then. All but six of the women continued to breast-feed for > or = 12 mo. With the exclusion of those whose menses returned before 18 wk postpartum (which could not have been due to the intervention), the proportion of women who were amenorrheic at 6 mo was 64.5% in the SF group, 80.0% in the FBF group, and 85.7% in the SF-M group (chi-square test = 4.13, P = 0.02; one-tailed test with the latter two groups combined). The total duration of LA did not differ significantly among groups. The most significant determinant of LA was time spent breast-feeding (min/d), which was in turn negatively associated (P = 0.06) with the infant's energy intake from complementary foods in regression analyses. These results indicate that there is a significant effect of introducing foods at 4 mo on the likelihood of amenorrhea at 6 mo postpartum, but not thereafter, and that this effect is not seen in mothers who maintain breast-feeding frequency.
Dewey
K G
KG
Department of Nutrition, University of California, Davis 95616-8669, USA. kgdewey@ucdavis.edu
Cohen
R J
RJ
Rivera
L L
LL
Canahuati
J
J
Brown
K H
KH
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000568:Amenorrhea; D001942:Breast Feeding; D002149:Energy Intake; D005260:Female; D006721:Honduras; D006801:Humans; D007223:Infant; D007225:Infant Food; D007774:Lactation; D008297:Male; D049590:Postpartum Period; D012044:Regression Analysis; D013997:Time Factors; D014886:Weaning