Maternal behavior and attachment in low-birth-weight twins and singletons.

Early mother-infant interaction and later security of attachment were assessed for 17 pairs of twins, 5 singleton survivors of twin pairs, and 20 singletons, all low-birth-weight preterm infants. Mother and infant behavior during home observations at 6 weeks and 3, 6, and 9 months was rated on scales developed by Ainsworth and Egeland and Brunquell. A, B, and C patterns of behavior in the Strange Situation conformed to the frequencies predicted from prior full-term samples and were not affected by twinship. However, the proportion of B1 and B4 dyads in the B group significantly exceeded that predicted from normative data. Mothers in B2 and B3 dyads were rated more sensitive and responsive than all others at all 4 observations. Contrary to our expectations that mothers in A and C dyads would receive the lowest ratings, this occurred only at 6 weeks. At later observations mothers in B1 and B4 dyads consistently received the lowest ratings. The discussion focuses on possible reasons for this unexpected finding.