Breastfeeding and growth during infancy among offspring of mothers with gestational diabetes mellitus: a prospective cohort study

Abstract

Background: Breastfeeding (BF) may protect against obesity and type 2 diabetes mellitus in children exposed to maternal diabetes in utero, but its effects on infant growth among this high-risk group have rarely been evaluated.

Objectives: The objective of this study was to evaluate BF intensity and duration in relation to infant growth from birth through 12 months among offspring of mothers with gestational diabetes mellitus (GDM).

Methods: Prospective cohort of 464 GDM mother-infant dyads (28% White, 36% Hispanic, 26% Asian, 8% Black, 2% other). Weight and length measured at birth, 6-9 weeks, 6 months and 12 months. Categorized as intensive BF or formula feeding (FF) groups at 6-9 weeks (study baseline), and intensity from birth through 12 months as Group 1: consistent exclusive/mostly FF, Group 2: transition from BF to FF within 3-9 months and Group 3: consistent exclusive/mostly BF. Multivariable mixed linear regression models estimated adjusted mean (95% confidence interval) change in z-scores; weight-for-length (WLZ), weight-for-age and length-for-age.

Results: Compared with intensive BF at 6-9 weeks, FF showed greater increases in WLZ-scores from 6 to 9 weeks to 6 months [+0.38 (0.13 to 0.62) vs. +0.02 (-0.15 to 0.19); p = 0.02] and birth to 12 months [+1.11 (0.87 to 1.34) vs. +0.53 (0.37 to 0.69); p < 0.001]. For 12-month intensity and duration, Groups 2 and 3 had smaller WLZ-score increases than Group 1 from 6 to 9 weeks to 6 months [-0.05 (-0.27 to 0.18) and +0.07 (-0.19 to 0.23) vs. +0.40 (0.15 to 0.64); p = 0.01 and 0.07], and birth to 12 months [+0.60 (0.39 to 0.82) and +0.59 (0.33 to 0.85) vs. +0.97 (0.75 to 1.19); p < 0.05].

Conclusions: Among offspring of mothers with GDM, high intensity BF from birth through 1 year is associated with slower infant ponderal growth and lower weight gain.

Keywords: Gestational diabetes mellitus; breastfeeding; growth patterns; infancy; prospective cohort.

Figure 1

(a–c) Infant growth measures [WLZ, WAZ, and LAZ-scores, mean, 95% confidence intervals (CI)] for each age and differences in the mean change in z-scores (slopes) for three time intervals (birth to 6–9 weeks, 6–9 weeks to 6 months, and 6 months to 12 months) and overall from birth to 12 months. Comparisons between infant feeding intensity groups at 6–9 weeks of age: intensive BF vs. intensive FF groups; p-values test the differences in mean change in z-scores; *p < 0.05, ^†p ≤ 0.01, ^‡p < 0.001. (a) Adjusted change in WLZ-score. (b) Adjusted c in WAZ-score. (c) Adjusted changes in LAZ-score. (a–c) Repeated measures linear regression models for infant feeding groups and infant age including an interaction by infant age (time) adjusted for race/ethnicity (White, Black, Hispanic, Asian/ other), gestational age at birth (weeks), maternal age, parity, education (years), pre-pregnancy BMI (kg/m²), total gestational weight gain (kg), GDM treatment type and gestational age at diagnosis of GDM (weeks); p-values for group differences in change in z-score measures of infant growth within each time interval (three time intervals), and overall time interval from birth to 12 months in the tables beside the graph. ^*p < 0.05, ^†p ≤ 0.01, ^‡p < 0.001. WLZ, weight-for-length; WAZ, weight-for-age; LAZ, length-for-age, BF, breastfeeding; FF, formula feeding.

Figure 1

(a–c) Infant growth measures [WLZ, WAZ, and LAZ-scores, mean, 95% confidence intervals (CI)] for each age and differences in the mean change in z-scores (slopes) for three time intervals (birth to 6–9 weeks, 6–9 weeks to 6 months, and 6 months to 12 months) and overall from birth to 12 months. Comparisons between infant feeding intensity groups at 6–9 weeks of age: intensive BF vs. intensive FF groups; p-values test the differences in mean change in z-scores; *p < 0.05, ^†p ≤ 0.01, ^‡p < 0.001. (a) Adjusted change in WLZ-score. (b) Adjusted c in WAZ-score. (c) Adjusted changes in LAZ-score. (a–c) Repeated measures linear regression models for infant feeding groups and infant age including an interaction by infant age (time) adjusted for race/ethnicity (White, Black, Hispanic, Asian/ other), gestational age at birth (weeks), maternal age, parity, education (years), pre-pregnancy BMI (kg/m²), total gestational weight gain (kg), GDM treatment type and gestational age at diagnosis of GDM (weeks); p-values for group differences in change in z-score measures of infant growth within each time interval (three time intervals), and overall time interval from birth to 12 months in the tables beside the graph. ^*p < 0.05, ^†p ≤ 0.01, ^‡p < 0.001. WLZ, weight-for-length; WAZ, weight-for-age; LAZ, length-for-age, BF, breastfeeding; FF, formula feeding.

Figure 2

(a–c) Infant growth shown as mean z-scores (95% confidence intervals) at each age and the differences in mean change in z-scores for three time intervals (birth to 6–9 weeks, 6–9 weeks to 6 months, and 6 months to 12 months) and overall from birth to 12 months. Comparisons of growth among combined intensity and duration scores (range 0 to 12) and the referent is Group 1; p-values test the change in z-scores (slope) differences for each interval and overall from birth to 12 months. ^*p <0.05, ^†p ≤ 0.01, ^‡p <0.001. (a) Comparison of adjusted changes in WLZ-scores (Groups 1, 2 and 3). (b) Comparison of adjusted changes in WAZ-scores (Groups 1, 2 and 3). (c) Comparison of adjusted changes in LAZ-scores (Groups 1, 2 and 3). (a–c) Repeated measures linear regression estimates of infant growth measures for three groups for combined intensity and duration infant feeding scores: Group 1 is Intensive FF since birth or from 3 months of age through 1 year (Referent), Group 2 is Transition from BF to FF mid-year, and Group 3 is Intensive BF through one year. All models are adjusted for infant age and an interaction by infant age (time), race/ethnicity (White, Black, Hispanic, Asian/other), gestational age at birth (weeks), maternal age, parity, education (years), pre-pregnancy BMI (kg/m²), total gestational weight gain (kg), GDM treatment type, and gestational age at diagnosis of GDM (weeks). ^*p <0.05, ^†p ≤0.01, ^‡p <0.001 for pairwise comparisons. WLZ, weight-for-length; WAZ, weight-for-age; LAZ, length-for-age; BF, breastfeeding; FF, formula feeding.

Figure 2

(a–c) Infant growth shown as mean z-scores (95% confidence intervals) at each age and the differences in mean change in z-scores for three time intervals (birth to 6–9 weeks, 6–9 weeks to 6 months, and 6 months to 12 months) and overall from birth to 12 months. Comparisons of growth among combined intensity and duration scores (range 0 to 12) and the referent is Group 1; p-values test the change in z-scores (slope) differences for each interval and overall from birth to 12 months. ^*p <0.05, ^†p ≤ 0.01, ^‡p <0.001. (a) Comparison of adjusted changes in WLZ-scores (Groups 1, 2 and 3). (b) Comparison of adjusted changes in WAZ-scores (Groups 1, 2 and 3). (c) Comparison of adjusted changes in LAZ-scores (Groups 1, 2 and 3). (a–c) Repeated measures linear regression estimates of infant growth measures for three groups for combined intensity and duration infant feeding scores: Group 1 is Intensive FF since birth or from 3 months of age through 1 year (Referent), Group 2 is Transition from BF to FF mid-year, and Group 3 is Intensive BF through one year. All models are adjusted for infant age and an interaction by infant age (time), race/ethnicity (White, Black, Hispanic, Asian/other), gestational age at birth (weeks), maternal age, parity, education (years), pre-pregnancy BMI (kg/m²), total gestational weight gain (kg), GDM treatment type, and gestational age at diagnosis of GDM (weeks). ^*p <0.05, ^†p ≤0.01, ^‡p <0.001 for pairwise comparisons. WLZ, weight-for-length; WAZ, weight-for-age; LAZ, length-for-age; BF, breastfeeding; FF, formula feeding.