Increased nuchal translucency and adverse pregnancy outcomes

Objective: To assess the adverse outcome in pregnancies with raised Nuchal translucency measurement.

Methods: This retrospective study was conducted at the Aga Khan University Hospital, Karachi, Pakistan between January 2001 and December 2015. Women attending the Fetal Medicine unit for first trimester screening by Nuchal translucency were included in the study. All pregnancies were followed up till delivery. Those with incomplete information about the delivery were excluded from the analysis. Pregnancy outcome was observed in normal Nuchal translucency measurements and in raised Nuchal translucency measurements.

Results: Out of the 1941 fetuses, there were 54 (2.8%) with raised Nuchal translucency measurement. Adverse pregnancy outcome was found in 32 (59.3%) of fetuses with raised Nuchal translucency measurement. Invasive testing was done in 15 (27.8%) of pregnancies with raised Nuchal translucency measurement. Among them there were nine (16.7%) cases with abnormal karyotype. It included six (11.1%) cases of trisomy 21, three (5.6%) cases of trisomy 13 and 18.

Conclusion: Raised Nuchal translucency measurement is associated with adverse pregnancy outcome. One in three fetuses are affected by it. Live birth in this group where there is no aneuploidy is around 3.7%.