Prevention of Obesity in Infants of Overweight and Obese Women

This is a clinical intervention study to calibrate infant milk or formula intake and modulate infant weight gain to prevent the development of infant obesity. The investigators will study only OW/OB women, as these patients are at increased risk of infants with excessive weight gain. The study will be conducted using clinical site at Harbor-UCLA Medical Center and at CTSI, The Lundquist Institute.

OW/OB women (pre-pregnant BMI >25-29.9 and ≥30) who are providing exclusive human milk via pumping and bottle (n= 120; 50% male and 50% female) will be recruited postpartum in the hospital or at postpartum visit (typically 3-6 weeks). Study women will be randomly assigned to a Standard Feed (SF) or Calibrated Feed (CF) groups. Mother-infant dyads will be seen at 2-week intervals for assessment of infant milk intake, weight gain, supine length, BMI and skinfold thickness till 6 months of age. Continuation of exclusive human milk will be confirmed with questionnaires.

In the SF group, mothers will provide bottled human milk based upon the volume guidelines: Total daily milk intake recommended will be calculated as infant's weight in ounces divided by 6, with individual feed volume calculated as the total daily volume divided by 6 to 8 (maternal discretion as to number of daily feeds). It is understood that mothers may elect an increased or reduced volume of feed dependent upon infant appetite, behavior, etc. throughout the study, at which time recommended feed volume will be adjusted by the standard formula based upon infant weight.

In the CF group, initial feeding volume will be based upon standard volume guidelines as described above. At the 2 week visits, should infants be within the 75%ile of WHO BMI growth curves, standard weight-based recommended feed volumes will be made. Should the infant be equal or greater than 75%ile of WHO BMI, the recommended human milk feed volume will be reduced by 5% of the weight-based determination, following a consultative assessment by our pediatric/neonatal physician. At subsequent visits, adjustments in human milk volume will continue if the infant exceeds 75%ile of WHO BMI, accommodating the normal increase in human milk intake with advancing weight. In no case, will the daily human milk volume be reduced by more than 10% from the weight-based calculation.

Should the infant be less than 10th percentile of WHO BMI, the maternal-infant dyad will be referred for a pediatric and nutrition consults to assess the cause and treatment for potential nutrient deficiency. At 6 months, the investigators will assess the distribution of infant weight BMI between SF and CF groups.