FETAL NUCHAL TRANSLUCENCY THICKNESS AT 10-14 WEEKS GESTATION AND CONGENITAL DIAPHRAGMATIC-HERNIA

Objective: To examine the possible association between increased fetal nuchal translucency thickness at 10-14 weeks and congenital diaphragm atic hernia. Methods: This was a multicenter ultrasound screening stud y for chromosomal defects in singleton pregnancies by a combination of maternal age and fetal nuchal translucency at 10-14 weeks' gestation. The prevalence of diaphragmatic hernia diagnosed prenatally or postna tally was calculated in the chromosomally normal group and in those pr egnancies resulting in live births with no dysmorphic features suggest ive of a chromosomal abnormality. We calculated the sensitivity of nuc hal translucency above the 95th centile of the normal range in the det ection of diaphragmatic hernia and the possible prognostic value of in creased nuchal translucency in the prediction of outcome. Results: The re were 78,639 pregnancies presumed to be normal chromosomally, includ ing 19 with diaphragmatic hernia. In four cases, the parents opted for termination of the pregnancy. The other 15 pregnancies resulted in li ve births; nine infants survived after successful surgical repair of t he hernia, but six neonates died because of pulmonary hypoplasia. At t he 10- to 14-week scan, the fetal nuchal translucency was above the 95 th centile for crown-rump length in seven (37%) cases of diaphragmatic hernia. The translucency was increased in five of the six cases that resulted in neonatal death, compared with two of the nine survivors (Z = 2.32, P < .05). Conclusion: The prevalence of diaphragmatic hernia in chromosomally normal fetuses is about one in 4000, and nearly 40% o f affected fetuses have increased nuchal translucency at 10-14 weeks' gestation. Increased nuchal translucency may be a marker of intrathora cic compression-related pulmonary hypoplasia. (C) 1997 by The American College of Obstetricians and Gynecologists.