Impact of head-to-abdominal circumference asymmetry on outcomes in growth-discordant twins.
OBJECTIVE
Our aim was to evaluate head-to-abdominal circumference asymmetry as a marker for adverse outcomes in growth-discordant twins.


METHODS
We conducted a retrospective cohort study of asymmetric and symmetric twins with > or =25% growth discordance, comparing their outcomes with those in concordant symmetric twins. Growth was termed asymmetric on the basis of a head circumference/abdominal circumference ratio at > or =95th percentile on ultrasonography performed < or =4 weeks before delivery.


RESULTS
We evaluated 572 twin pairs. Asymmetric discordant twins were more likely than symmetric concordant twins to be delivered at < or =34 weeks' gestation (57% vs. 27%), to require intubation (36% vs. 7%), to remain in intensive care >1 week (36% vs 3%), and to have an outcome composite that included respiratory morbidity, intraventricular hemorrhage, sepsis, or neonatal death (29% vs 6%), all P<.05. Symmetric discordant and symmetric concordant twins had similar outcomes.


CONCLUSIONS
Discordant twins with head-to-abdominal circumference asymmetry have an increased risk of morbidity. Moreover, in the absence of asymmetry, outcomes are comparable among discordant and concordant twins.
Dashe
J S
JS
Department of Obstetrics and Gynecology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.
McIntire
D D
DD
Santos-Ramos
R
R
Leveno
K J
KJ
D000005:Abdomen / Q000196:embryology*; D015331:Cohort Studies; D005314:Embryonic and Fetal Development; D005260:Female; D005333:Fetus / Q000033:anatomy & histology* / Q000502:physiology*; D006257:Head / Q000196:embryology*; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D012189:Retrospective Studies; D012307:Risk Factors; D014427:Twins