Comparison of spontaneous fetal loss rates between women with singleton and twin pregnancies after mid‐trimester amniocentesis ‐ A historical cohort study

Abstract

Objective To assess and compare fetal loss rates before 28 weeks of singleton and twin pregnancies after mid‐trimester amniocentesis. Method This historic cohort study included 13 773 women with singletons and 426 women with twins undergoing mid‐trimester amniocentesis from 1/2015 to 3/2017. Pregnancies resulting in termination or selective reduction before 28 weeks were excluded, as well as twin gestations undergoing single‐puncture amniocentesis. Fetal loss rates were compared between singleton and twins taking into account maternal characteristics, amniocentesis procedure, and fetal chromosomal abnormalities. Results The rates of fetal chromosomal abnormalities were similar in singleton and twin gestations (1.13% vs 0.70%, P = .253). No difference was found in maternal or fetal characteristics, or amniocentesis procedure between the two groups. The fetal loss rate was significantly higher in twin compared with singleton pregnancies (1.91% vs 0.24%, P < .001, RR = 8.25 [95% CI: 4.51 to 15.09]). The fetal loss rate between monochorionic twins and dichorionic twins was similar (1.80% vs 1.78%, P = 1.000). Conclusions Twin pregnancies have higher risk of fetal loss after mid‐trimester amniocentesis, which cannot be explained by differences in rates of fetal chromosomal abnormalities, maternal characteristic, or amniocentesis technique.

Pregnancy Loss After Amniocentesis with Double-Needle Insertions in Twin Pregnancies

“…Only abnormal ultrasound findings were associated with increased risk, similar to that reported by Cahill et al (2009). Likewise, some other studies also reported that advanced maternal age, parity, conception mode and chorionicity did not influence pregnancy loss after amniocentesis (Cahill et al, 2009;Chen et al, 2020;Daskalakis et al, 2009;Dechnunthapiphat et al, 2020;Lenis-Cordoba et al, 2013). To the authors' knowledge, there are no earlier reports on cervical length as a risk factor in twin pregnancies after amniocentesis.…”

“…A more recent study of twin pregnancies not in the meta-analysis included 332 twin pregnancies undergoing amniocentesis, and the pregnancy loss rate before 24 weeks was 3.0% (Dechnunthapiphat et al, 2020). Chen et al (2020) reported that the pregnancy loss rate before 28 weeks in 418 twin pregnancies was 1.91%. The pregnancy loss rate only related to the procedure in our study was the lowest among all the studies, mainly due to sticking to the standard protocol that helped exclude potential infection and cervical incompetence.…”

“…In the Cochrane database, the spontaneous miscarriage rate after amniocentesis in singleton gestations spans between 0.13% and 0.33%, while there are no data for twin gestations (Alfirevic et al, 2017). The risk of pregnancy loss in twin gestations reported in the last 20 years varies from 0% to 4.2% (Antsaklis et al, 2002;Cahill et al, 2009;Chen et al, 2020;Daskalakis et al, 2009;Dechnunthapiphat et al, 2020;Kalogiannidis et al, 2011;Kan et al, 2012;Kim et al, 2019;Krispin et al, 2019;Lenis-Cordoba et al, 2013;Millaire et al, 2006;Simonazzi et al, 2010;Sperling et al, 2019;Supadilokluck et al, 2009;Toth-Pal et al, 2004;Yukobowich et al, 2001). One recent systematic review demonstrated that the pooled pregnancy loss rate before 24 weeks and within 4 weeks after the amniocentesis procedure in twin pregnancies were 2.1% and 2.1%, respectively, which were as high as the background risk in twin pregnancy without undergoing the procedure (Di Mascio et al, 2020).…”

Noninvasive prenatal testing, ultrasonographic findings and poor prenatal diagnosis rates for twin pregnancies: a retrospective study

“…Invasive prenatal diagnosis is recommended when the NIPT result indicates a high risk of abnormalities or when ultrasound suggests a foetal structural malformation. Amniocentesis in twin pregnancies carries a slightly higher risk of foetal loss than in singleton pregnancies [ 9 ], and many twin pregnancies are conceived through artificially assisted reproduction or at an advanced age; therefore, it is a common phenomenon for twin-pregnant women to refuse prenatal diagnosis after a long period of hesitation.…”

Does chorionic villus sampling protect against fetal loss in twin pregnancy at high background risk of spontaneous miscarriage?

“…In this study 3 , the primary outcome was the rate of fetal loss at any stage during pregnancy following CVS or first-trimester scan. Instead, miscarriage, defined as fetal loss before 24 weeks' gestation, might be more suitable for assessing the risk of CVS, as fetal death late in gestation is more likely to be due to other causes related to twin pregnancy itself [4][5][6] . It would be interesting to know whether the same conclusions could be drawn if the primary outcome measure were restricted to miscarriage.…”