Cordocentesis in multifetal pregnancies

Maternal Risk Factors and Their Effect on Outcome and Procedure-Related Complications in Cordocentesis: A Multicenter Retrospective Study

BACKGROUND

Cordocentesis is used in clinical situations in which lower-risk diagnostic procedures do not deliver the desired results. The aim of this study was to evaluate the risk for procedure-related complications and fetal loss in correlation to maternal risk factors.

METHODS

This is a multicenter retrospective study investigating the complications, risk factors and perinatal outcome of diagnostic cordocentesis between 1998 and 2019 in three different centers.

RESULTS

A total of 1806 cordocenteses were performed and procedure-related complications (IUFD within 48 h, contractions, bradycardia, unsuccessful puncture, chorioamniotic separation) were noted in 1.6% of cases. Fetuses with chromosomal aberrations, intrauterine growth restriction and hydropic fetuses had a significantly higher rate of fetal loss compared to other indications. Fetal blood sampling (FBS) performed before 17+0 weeks of gestation was associated with a higher risk of procedure-related complications. Maternal BMI ≥ 40 increased the risk for fetal loss, whereas maternal age, number of previous miscarriages, number of previous abortions, history of vaginal bleeding or nicotine abuse did not affect the risk for complications or overall fetal loss rate.

CONCLUSIONS

In the hands of experienced operators, FBS is a safe way to further fetal diagnostics, and the risk of complications is low.

Cordocentesis-associated fetal loss and risk factors: single-center experience with 6650 cases

OBJECTIVES

To identify procedural risk factors associated with fetal loss following cordocentesis and to determine the rate of cordocentesis-related fetal loss associated with the current cordocentesis protocol used in our institution.

METHODS

This was a retrospective cohort study of pregnancies that underwent midpregnancy cordocentesis in a single center (a tertiary hospital, teaching school), between 1992 and 2018, based on data retrieved from our prospective database. All consecutive cases were validated to retrieve those meeting the eligibility criteria, which included: singleton pregnancy without underlying maternal disease, normal fetus (no structural or chromosomal abnormality or severe disorder), gestational age between 16 and 24 weeks at the time of the procedure and availability of pregnancy outcome. Cases that resulted in termination of pregnancy were excluded. We assessed the effect of prior cordocentesis model training on the fetal-loss rate and procedure-related complications, and evaluated potential risk factors of fetal loss secondary to cordocentesis, including procedure difficulty, placenta penetration, prolonged bleeding, fetal bradycardia, puncture site and early gestational age at procedure. Pregnancy outcomes were compared between the study group and a control group of women, who did not undergo cordocentesis, selected randomly at a 1:1 ratio from our obstetric database.

RESULTS

A total of 10 343 procedures were performed during the study period, of which 6650 met the eligibility criteria and were included in the analysis. The fetal-loss rate in the first 60 procedures (early practice) of six operators (n = 360 procedures), who did not have prior model training, was significantly higher than that during the early practice of 18 operators (n = 1080 procedures) with prior model training (6.9% vs 1.6%; P < 0.001); whereas the fetal-loss rate in the next 60 procedures of practice was comparable between the two groups. After excluding the first 360 procedures of the groups without prior model training, the overall fetal-loss rate in pregnancies that underwent cordocentesis was significantly higher than that in the control group (1.6% vs 1.0%; P < 0.001). Considering the fetal-loss rate in the normal controls as background loss, the incremental cordocentesis-associated fetal-loss rate was 0.6%. Penetration of the placenta (odds ratio (OR), 2.65 (95% CI, 1.71-4.10)), prolonged bleeding from the puncture site (OR, 10.85 (95% CI, 5.27-22.36)) and presence of fetal bradycardia (OR, 3.32 (95% CI, 1.83-6.04)) during cordocentesis were independent risk factors associated with fetal loss.

CONCLUSIONS

Cordocentesis model training markedly reduces fetal loss during the early learning curve of practice. Thus, cordocentesis practice without prior model training should not be acceptable. Significant procedural risk factors for fetal loss secondary to cordocentesis are placental penetration, prolonged bleeding and fetal bradycardia. Cordocentesis-related fetal loss may be only 0.6%, much lower than the rate reported previously. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.