Ultrasound Obstet Gynecol. 2021 May 26. doi: 10.1002/uog.23694. Online ahead of print.
ABSTRACT
OBJECTIVES: To estimate the chorionic villus sampling (CVS) related risk of fetal loss after adjustment for chorionicity, nuchal translucency thickness (NT), intertwin discordance in crown-rump length (CRL), maternal demographic characteristics and serum pregnancy associated plasma protein-A (PAPP-A) and free ß-human chorionic gonadotropin (hCG).
METHODS: This was a multicentre study from eight fetal medicine units in which the leadership were trained at the Harris Birthright research centre for fetal medicine in London and the protocols for screening, invasive testing and pregnancy management are similar. The study population of 8581 twin pregnancies undergoing ultrasound examination at 11-13 weeks’ gestation, included 316 dichorionic (DC) and 129 monochorionic (MC) twins that had CVS. Multivariable logistic regression analysis with backward step wise elimination was used to examine whether CVS provided a significant independent contribution in the prediction of risk of fetal loss after adjusting for maternal and pregnancy characteristics, including materal age, racial origin, weight, method of conception, smoking status, parity, chorionicity, intertwin discordance in CRL, fetal NT ≥95th percentile, free ß-hCG and PAPP-A MoM. Similarly, within the CVS groups multivariable logistic regression analysis was used to investigate the effect of the number of intrauterine needle insertions and size of the needles on the risk of fetal loss.
RESULTS: There are four main findings of this study. First, in twin pregnancies undergoing CVS, compared to those that do not have CVS, there is a 2-fold increased risk of fetal loss at <24 weeks’ gestation and loss at any stage in pregnancy. Second, the factors providing a significant independent contribution in the prediction of miscarriage or fetal loss in twin pregnancies are increased maternal weight, Black racial origin, monochorionicity and more so monoamnionicity, large intertwin discordance in CRL and high fetal NT and in the case of total fetal loss there is also a contribution from low serum PAPP-A. Third, there is a trend for an increased risk of fetal loss from CVS after adjustment for maternal and pregnancy characteristics but this does not reach statistical significance. Fourth, in the twin pregnancies that had CVS there is no significant contribution to fetal loss from the number of intrauterine needle insertions or needle size.
CONCLUSION: The 2-fold increased risk of fetal loss following CVS in twin pregnancies can to a great extent be explained by maternal and pregnancy characteristics rather than the invasive procedure itself. This article is protected by copyright. All rights reserved.
PMID:34038977 | DOI:10.1002/uog.23694
