Growth discordancy in appropriate for gestational age, term twins.

We compared 14 term (37 weeks or more), discordant (15% or more birth weight difference), but not growth-retarded (2500 g or larger) twin pairs with 28 randomly selected term and appropriate for gestational age twin pairs without discordancy. The comparison of the two subgroups showed no significant difference in maternal age, parity, gestational age, incidence of maternal hypertension, or perinatal outcome. It is suggested that discordancy is not a risk factor when the twin pair has reached term and the lighter twin weighs at least 2500 g.

Predisposing factors in the formation of true knots of the umbilical cord--analysis of morphometric and perinatal data.

Fifty-four umbilical cords with a true knot were analysed and compared to 108 normal cords. True knots were found in 1.22% of births.

Characterization of the growth-discordant twin.

A computer-assisted analysis of perinatal variables was undertaken in order to characterize the growth-discordant twin. We studied 124 twin pairs grouped at four degrees of discordancy: over 5, 10, 15, and 20% birth weight difference, using the larger twin as 100%. Twins with birth weight discrepancy below these figures were considered concordant.