Growth and development of children conceived by in vitro fertilization.

To assess the physical and mental development of infants born after in vitro fertilization (IVF), we performed a general physical and developmental examination (Bayley and Stanford-Binet scales) on a cohort of 116 IVF children, conceived and born at our institution between February 1985 and March 1989, and on 116 non-IVF matched controls. Study and control groups were each composed of 66 singletons, 19 pairs of twins and 4 sets of triplets, whose age at examination ranged from 12 to 45 months. The developmental indices of IVF infants were within the normal range and did not differ from those of their matched controls. The indices were positively correlated to gestational age, birth weight, head circumference at birth and at examination, and mother's education. Mean birth weight, gestational age, and birth weight percentile of IVF infants were lower than the mean of the healthy population. Mean percentiles of weight and length at examination (mean age 22.4 months) were equally low but did not differ from those of the matched controls. However, mean percentiles of head circumference at birth and at examination compare well with the normal mean, both in IVF and control groups. Twins and triplets (IVF and controls) had significantly lower physical and mental indices as compared to singletons.