Browsing by Author "Chaveeva, P."
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Item Risk of fetal loss after chorionic villus sampling in twin pregnancy derived from propensity score matching analysis.(Ultrasound in Obstetrics & gynecology, 2021) Gil Mira, María del Mar; Rodríguez Fernández, Miguel; Elger, Tania; Akolekar, R.; Syngelaki, A.; De Paco Matallana, C.; Molina, ,F. S.; Gallardo Arocena, M.; Chaveeva, P.; Persico, N.; Accurti, V.; Kagan, K. O.; Prodan, N.; Cruz, J.; Nicolaides, K. H.Objective To estimate the risk of fetal loss associated with chorionic villus sampling (CVS) in twin pregnancy, using propensity score analysis. Methods This was a multicenter cohort study of women with twin pregnancy undergoing ultrasound examination at 11–13 weeks' gestation, performed in eight fetal medicine units in which the leadership were trained at the Harris Birthright Research Centre for Fetal Medicine in London, UK, and in which the protocols for screening, invasive testing and pregnancy management are similar. The risk of death of at least one fetus was compared between pregnancies that had and those that did not have CVS, after propensity score matching (1:1 ratio). This procedure created two comparable groups by balancing the maternal and pregnancy characteristics that lead to CVS being performed, similar to how randomization operates in a randomized clinical trial. Results The study population of 8581 twin pregnancies included 445 that had CVS. Death of one or two fetuses at any stage during pregnancy occurred in 11.5% (51/445) of pregnancies in the CVS group and in 6.3% (515/8136) in the non-CVS group (P < 0.001). The propensity score algorithm matched 258 cases that had CVS with 258 non-CVS cases; there was at least one fetal loss in 29 (11.2%) cases in the CVS group and in 35 (13.6%) cases in the matched non-CVS group (odds ratio (OR), 0.81; 95% CI, 0.48–1.35; P = 0.415). However, there was a significant interaction between the risk of fetal loss after CVS and the background risk of fetal loss; when the background risk was higher, the risk of fetal loss after CVS decreased (OR, 0.46; 95% CI, 0.23–0.90), while, in pregnancies with a lower background risk of fetal loss, the risk of fetal loss after CVS increased (OR, 2.45; 95% CI, 0.95–7.13). The effects were statistically significantly different (P-value of the interaction = 0.005). For a pregnancy in which the background risk of fetal loss was about 6% (the same as in our non-CVS population), there was no change in the risk of fetal loss after CVS, but, when the background risk was more than 6%, the posterior risk was paradoxically reduced, and when the background risk was less than 6%, the posterior risk increased exponentially; for example, if the background risk of fetal loss was 2.0%, the relative risk was 2.8 and the posterior risk was 5.6%. Conclusion In twin pregnancy, after accounting for the risk factors that lead to both CVS and spontaneous fetal loss and confining the analysis to pregnancies at lower prior risk, CVS seems to increase the risk of fetal loss by about 3.5% above the patient's background risk. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.Item Risk of miscarriage after chorionic villus sampling.(Ultrasound in Obstetrics and Gynecology, 2020) Gil Mira, María del Mar; Molina, F. S.; Rodríguez Fernández, M.; Delgado, J. L.; Carrillo, M. P.; Jani, J.; Plasencia, W.; Stratieva, V.; Maíz, N.; Carretero, P.; Lismonde, A.; Chaveeva, P.; Burgos, J.; Santacruz Martín, Belén; Zamora, J.; De Paco Matallana, C.Objective To estimate the risk of miscarriage associated to chorionic villus sampling (CVS). Methods This was a retrospective cohort study performed in eight fetal‐medicine units in Spain, Belgium and Bulgaria. Two populations were included: first, all singleton pregnancies attending to their first‐trimester assessment in Murcia, Spain, and second, all singleton pregnancies having a CVS following first‐trimester assessment at any of the participating centers. We used propensity score matching analysis to estimate the association between CVS and miscarriage. We compared risks of miscarriage of CVS and non‐CVS groups after propensity score matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that lead to CVS, in a similar way in which randomization operates in a randomized clinical trial. Results The study population consisted of 22,250 participants in the non‐CVS group and 3,613 in the CVS group. The incidence of miscarriage in the CVS group was 2.1% (77/3,613), which was significantly higher than the 0.9% (207/22,250) in the non‐CVS group (p <0.001). The propensity score algorithm matched 2,122 CVS cases with 2,122 non‐CVS cases including 40 (1.9%) and 55 (2.6%) miscarriages in the CVS and non‐CVS groups, respectively (OR 0.72 [95% CI 0.48 to 1.10]; p = 0.146). However, we found a significant interaction between the CVS risk of miscarriage and the risk of aneuploidies, suggesting a different effect of the CVS for different baseline characteristics in such a way that, when the risk of aneuploidies is low, the risk after CVS increases (OR 2.87 [95% CI 1.13 to 7.30]) but when the risk is high, the risk after CVS is paradoxically reduced (OR 0.47 [95% CI 0.28 to 0.76]), presumably due to prenatal diagnosis and termination of major aneuploidies that would have otherwise resulted in spontaneous miscarriage. Conclusions The risk of miscarriage in women having a CVS is about 1% higher than in women without CVS, although this excess risk is not entirely due to the invasive procedure but to some extent the demographic and pregnancy characteristics of the patient undergoing CVS. After accounting for these risk factors and confining the analysis to low‐risk pregnancies, CVS seems to increase the risk of miscarriage about three times above the patient’s background‐risk. Although this is a substantial increase in relative terms, in pregnancies without risk factors, the risk of miscarriage after CVS will still remain low and similar to or slightly higher than that of the general population. For example, if her risk of aneuploidy is 1 in a 1,000 (0.1%), her risk of miscarriage after CVS will increase to 0.3% (0.2% higher).