Growth in the first four years: IV. Correlations with parental measures in small-for-dates and large-for-dates babies.

Parent-child correlations for weight, height and head circumference on eight occasions between birth and 4 years were estimated within groups of 212 small-for-dates (SFD), 208 average-for-dates (AFD) and 221 large-for-dates (LFD) children. For mothers and fathers in the SFD and AFD groups, and fathers in the LFD group, correlations for weight were generally low in the first year, with moderate increases up to 4 years. No correlations for weight at any age were found between mothers and LFD children. There was a gradual rise in correlations for length in all three groups for both mothers and fathers between birth and 4 years. Head circumference correlations in the AFD and LFD groups were relatively high at birth and showed little change thereafter. Mother-child correlations for head circumference in the SFD group were absent at birth, but then rose sharply to a value comparable with the AFD parents' correlations at 18 months, with the little change thereafter. No SFD father-child correlations for head circumference were found at any age. Children's standards of weight and head circumference adjusted for mid-parental measures would, in some cases, be misleading.