Impact of chorionicity on first‐trimester nuchal translucency screening in ART twin pregnancies

Abstract

Measurement of NT thickness in DC ART twins achieves comparable results with twins conceived spontaneously. Conclusions in MC twins are limited; however, higher NT MoM was not related to TTTS or selective intrauterine growth restriction.

Nuchal translucency in twins according to mode of assisted conception and chorionicity

“…In a previous study, our group did not find a statistically significant difference in median or mean NT‐MoM values between a small number of ART pregnancies ( n = 128) and spontaneous twin pregnancies ( n = 70). Four other studies, all relatively small, have addressed the issue (Table ), one reporting a statistically significant reduction in NT for ART pregnancies and one, as the current study, a statistically significant increase. Two of these studies reported average NT separately for cases of IVF and ICSI and there were no consistent differences (Table ).…”

“…Four other studies, all relatively small, have addressed the issue (Table ), one reporting a statistically significant reduction in NT for ART pregnancies and one, as the current study, a statistically significant increase. Two of these studies reported average NT separately for cases of IVF and ICSI and there were no consistent differences (Table ).…”

“…One study reported a statistically significant lower median of 0.87 MoM ( n = 22) in MC fetuses compared with 1.00 MoM in DC fetuses ( n = 174). To the best of our knowledge, only one study compared NT levels in twins according to both chorionicity and ART. In DC twins no significant difference in median NT between ART (1.06 MoM; n = 326) and spontaneous pregnancies (1.03 MoM; n = 234) was found.…”

Monochorionic twins after in‐vitro fertilization: do they have poorer outcomes?

“…Pregnancies were classified according to the mode of conception as spontaneous vs IVF or ICSI (IVF/ICSI). Pregnancies resulting from ovulation induction were not included in the analysis in order to create a more homogeneous study group and facilitate comparison with earlier published series 13,14,16,28 . Women who conceived after insemination in a natural cycle, without ovulation induction, were included in the spontaneous-conception group, and women who conceived after egg donation were included in the IVF/ICSI group.…”

“…It is uncertain how IVF affects the outcome of monochorionic twin pregnancies, which are already at higher risk of adverse pregnancy outcome than dichorionic pregnancies because of the presence of vascular anastomoses and potential transfusion imbalances 12 . Given its increased use, it is essential to understand better whether IVF further affects the outcome of these twins; however, the findings of studies on this topic are inconsistent [13][14][15] . Some authors have suggested lower survival rates in monochorionic diamniotic (MCDA) twins after IVF, but their results failed to show statistical significance, most probably owing to small sample size 14,16,17 .…”