Retrospective cohort study of a new infant formula during the first 6 months of life: Reflections on growth curves, human milk and formula feeding

Background: Optimil® is an infant formula, manufactured in Israel and introduced to the market in May 2008. Objectives: To assess the effect of this formula on infant growth. Method: The study group comprised 52 infants who for the first 6 months of life consumed Optimil, which constituted at least 25% of their total daily intake. Anthropometric data were collected from the records of the well-baby clinics. Weight, length and head circumference at baseline and 3 months thereafter were converted to gender and age-matched standard deviation Z-scores. As an exploratory uncontrolled analysis, questionnaires were sent to the caregivers to assess satisfaction with the formula and to note the rate of constipation, irritability and vomiting as well as apparent palatability. Results: The baseline Z-scores of all three parameters were below zero but increased significantly after 3 months (-0.2 ± 0.88 to 0.12 ± 0.88, P = 0.013 for weight; -0.44 ± 0.87 to 0.10 ± 0.72, P < 0.001 for length; and -0.58 ± 0.78 to -0.1 ± 0.76, P < 0.001 for head circumference). There was a significant dose-response effect of the formula with weight gain. The formula was generally well accepted, with 8% constipation, 8% vomiting and 6% significant irritability. Conclusions: This study provides the first evidence that infants consuming Optimil under age 6 months have adequate growth. Nonetheless, breastfeeding during this period should be preferred in almost all cases.