A novel approach to intertriplet birth weight discordance.
OBJECTIVE
This study was undertaken to evaluate intertriplet birth weight discordance.


METHODS
Birth weight discordance greater than 25% was evaluated in a cohort of 2804 US live-born triplets. Symmetric and high- and low-skew sets were defined by the rank of the middle triplet between the heavier and the lighter triplets. Frequencies of discordance level and type were analyzed by gestational age, parity, and total triplet birth weight.


RESULTS
Discordance of 25.1% to 35% and greater than 35% was found in 19.4% and 9.5% of the triplets analyzed, respectively. Frequencies of greater than 25% discordant sets demonstrated polynomial relationship to gestational age (R (2) = 0.94, P <.001) total triplet birth weight deciles (R (2) = 0.97, P <.001). Frequencies of discordance type are unchanged throughout gestation.


CONCLUSIONS
Birth weight discordance in triplets is frequent and large and implies exhaustion of fetal growth potential despite a uterine environment that appears to perform at maximal effort in these pregnancies.
Blickstein
Isaac
I
Department of Obstetrics and Gynecology, Kaplan Medical Center and the Hadassah-Hebrew University School of Medicine, Rehovot, Israel. blick@netvision.net.il
Jacques
Debbie L
DL
Keith
Louis G
LG
D001724:Birth Weight; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D010298:Parity; D014310:Triplets