Adverse outcome following selective termination of presenting twin vs non-presenting twin

Perinatal outcomes of selective termination in dichorionic twin pregnancies: a retrospective study from a single center

OBJECTIVE

Selective termination (ST) is an appropriate procedure for managing discordant fetal anomalies in dichorionic diamniotic (DCDA) twin pregnancies. The aim of this study was to investigate the perinatal outcomes of ST at different gestational ages in DCDA twin pregnancies.

METHODS

This retrospective study was conducted on DCDA twin pregnancies with STs at West China Second University Hospital between January 2012 and December 2022. According to the gestational age at which ST was performed, the patients were assigned to four groups: Group 1 (13 to 17 + 6 weeks), Group 2 (18 to 23 + 6 weeks), Group 3 (24 to 27 + 6 weeks), and Group 4 (≥ 28 weeks).

RESULTS

We identified 230 patients for this study. The overall rates of miscarriage, preterm delivery at < 32 weeks, and term delivery were 1.3%, 10.5%, and 50%, respectively, while the rates of live birth and neonatal survival were 98.7% and 98.2%, respectively. The rate of term birth was highest (70.6%) and the birth weight was heaviest (2931 ± 535 g) in Group 1 (p = 0.000). In the presence of a fetus subjected to feticide, the mean delivery age was earlier than that in the non-presenting group (p = 0.017); accordingly, the mean birth weight in the feticide group was lower (2366 ± 628 g) than that in the non-presenting group (2590 ± 634 g) (p = 0.011). When we examined the relative relationship between reduction weeks and delivery weeks of twins by correlation analysis, we observed that with regard to maternal prognosis, two pregnancies involved preterm premature rupture of membranes (PPROM) at 7 days and 3 days after the procedure. Intrauterine infection occurred in two patients in Group 4, but there were no maternal deaths or maternal coagulatory abnormalities.

CONCLUSIONS

Optimal perinatal outcomes were obtained by ST of DCDA pregnancies before 18 weeks, regardless of whether or not the reduced fetus was the presenting twin. However, if legally possible, late (i.e., after 28 weeks) procedures can be a safe alternative for patients diagnosed after the 18th week of gestation. Overall, we herein noted a negative correlation between the procedure week and the delivery week in this study. Moreover, ST of the non-presenting twin was associated with a heavier birth weight and later gestational age at delivery.

Mediastinal Teratoma in a Twin Pregnancy: A Case Report

Fetal mediastinal teratomas are rare tumors that can lead to serious complications such as fetal hydrops and intrauterine fetal death. Early prenatal diagnosis is critical in patient counseling, management, and preparation for postnatal interventions. In this report, we present the case of a 27-year-old woman in the second trimester of a dichorionic diamniotic twin pregnancy, in which the presenting fetus was diagnosed with a mediastinal teratoma and subsequently developed fetal hydrops, leading to intrauterine death. The diagnosis was initially made via ultrasound and the second twin exhibited no major anomalies. Following the fetal demise of the affected twin, a cesarean section was performed due to suspected maternal complications, and the surviving twin was delivered prematurely. This case highlights the importance of multidisciplinary collaboration in the management of complex twin pregnancies and underscores the challenges of diagnosing and managing rare fetal anomalies.

Late selective termination in dichorionic twins: comparing late second and third trimester procedures

RESEARCH QUESTION

Do perinatal outcomes of selective termination performed in the late second versus third trimester differ and what risk factors are associated with subsequent preterm birth?

DESIGN

This is a retrospective cohort study of late selective terminations performed in dichorionic twins between 2009 and 2021. Perinatal outcomes were compared between two groups: group A, late second trimester (20.2 to 24.2 weeks, n = 26), and group B, third trimester (≥28.2 weeks, n = 55) selective terminations. Univariate and multivariate analyses were conducted to identify factors associated with post-procedure preterm birth.

RESULTS

In total, 81 dichorionic twin pregnancies were included. There were no pregnancy losses but 16% (13/81) of cases experienced complications. Group A had a higher median birthweight centile (36.5th versus 15th centile, P = 0.002) and lower rates of intrauterine growth restriction (IUGR) and Caesarean delivery (11.5% versus 32.7%, P = 0.04; and 26.9% versus 61.8%, P = 0.003) than group B. Preterm birth rates were similar (46.2% versus 63.6%, P = 0.15). Multiple regression revealed that reduction of the presenting twin and cervical length ≤35 mm were independently associated with post-procedure preterm birth (odds ratio [OR] 8.7, P = 0.001, 95% confidence interval [CI] 2.5-29.8; OR 3.8, P = 0.015, 95% CI 1.3-11).

CONCLUSIONS

Late second trimester selective termination is associated with a higher birthweight centile and lower rates of IUGR and Caesarean delivery, compared with third trimester selective termination. Cervical length 35 mm or less and reduction of the presenting twin are independent risk factors for post-procedural preterm birth. These findings may help determine the optimal time to perform a late selective termination.

Perinatal outcomes between immediate vs deferred selective termination in dichorionic twin pregnancies with fetal congenital anomalies: a French multicenter study

BACKGROUND

Because selective termination for discordant dichorionic twin anomalies carries a risk of pregnancy loss, deferring the procedure until the third trimester can be considered in settings where it is legal.

OBJECTIVE

To determine whether perinatal outcomes were more favorable following deferred rather than immediate selective termination.

STUDY DESIGN

A French multicenter retrospective study from 2012 to 2023 on dichorionic twin pregnancies with selective termination for fetal conditions, which were diagnosed before 24 weeks gestation. Pregnancies with additional risk factors for late miscarriage were excluded. We defined 2 groups according to the intention to perform selective termination within 2 weeks after the diagnosis of the severe fetal anomaly was established (immediate selective termination) or to wait until the third trimester (deferred selective termination). The primary outcome was perinatal survival at 28 days of life. Secondary outcomes were pregnancy losses before 24 weeks gestation and preterm delivery.

RESULTS

Of 390 pregnancies, 258 were in the immediate selective termination group and 132 in the deferred selective termination group. Baseline characteristics were similar in both groups. Overall survival of the healthy co-twin was 93.8% (242/258) in the immediate selective termination group vs 100% (132/132) in the deferred selective termination group (P<.01). Preterm birth <37 weeks gestation was lower in the immediate than in the deferred selective termination group (66.7% vs 20.2%; P<.01); preterm birth <28 weeks gestation and <32 weeks gestation did not differ significantly (respectively 1.7% vs 0.8%; P=.66 and 8.26% vs 11.4%; P=.36). In the deferred selective termination group, an emergency procedure was performed in 11.3% (15/132) because of threatened preterm labor, of which 3.7% (5/132) for imminent delivery.

CONCLUSION

Overall survival after selective termination was high regardless of the gestational age at which the procedure was performed. Postponing selective termination until the third trimester seems to improve survival, whereas immediate selective termination reduces the risk of preterm delivery. Furthermore, deferred selective termination requires an expert center capable of performing the selective termination procedure on an emergency basis if required.

Effect of cannula insertion site during fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia on preterm prelabor rupture of membranes

OBJECTIVE

To assess whether the cannula insertion site on the maternal abdomen during fetal endoscopic tracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH) was associated with preterm prelabor rupture of membranes (PPROM) before balloon removal.

METHODS

This was a multicenter retrospective study of consecutive pregnancies with isolated left- or right-sided CDH that underwent FETO in four centers between January 2009 and January 2021. The site for balloon insertion was categorized as above or below the umbilicus. One propensity score was analyzed in both groups to calculate an average treatment effect (ATE) by inverse probability of treatment weighting. Logistic regression and Cox proportional hazard regression including the ATE weights were performed to examine the effect size of entry point on the frequency and timing of PPROM before balloon removal.

RESULTS

A total of 294 patients were included. The mean ± SD gestational age at PPROM was 33.45 ± 2.01 weeks and the mean rate of PPROM before balloon removal was 25.9% (76/294). Gestational age at FETO was later in the below-umbilicus group (mean ± SD, 29.47 ± 1.29 weeks vs 29.00 ± 1.25 weeks; P = 0.002) and the duration of FETO was longer in the above-umbilicus group (median, 14.49 min (interquartile range (IQR), 8.00-21.00 min) vs 11.00 min (IQR, 7.00-14.49 min); P = 0.002). After balancing for possible confounding factors, trocar entry point below the umbilicus did not increase the risk of PPROM before balloon removal (adjusted odds ratio, 1.56 (95% CI, 0.89-2.74); P = 0.120) and had no effect on the timing of PPROM before balloon removal (adjusted hazard ratio, 1.56 (95% CI, 0.95-2.55); P = 0.080).

CONCLUSION

There was no evidence that uterine entry site for FETO was correlated with the risk of PPROM before balloon removal. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Outcomes of fetal reduction versus expectant management in dichorionic triamniotic triplets

OBJECTIVE

To compare the outcomes of dichorionic triamniotic (DCTA) triplets who underwent fetal reduction (FR) to singletons or twins with those managed expectantly.

METHODS

We conducted a retrospective study of DCTA triplets with three living fetuses at 11-14 weeks over a 7-year period. Pregnancy outcomes were compared following different management strategies.

RESULTS

Of 108 included patients, 22 underwent expectant management (EM), 28 were reduced to dichorionic diamniotic twins, and 58 to singletons. The median gestational age at birth for EM, FR to twins, and singletons was 33.1 weeks, 37.0 weeks, and 38.6 weeks, respectively (P < 0.001). Prematurity before 37 and 34 weeks was less common following FR to singletons and twins than in ongoing triplets (18.9%, 46.2% and 90.5%, P < 0.001; 13.2%, 26.9% and 57.1%, P < 0.001). Neonatal birth weight was higher in triplets reduced to singletons and twins compared with EM cases (3140g, 2315g, and 1860g, P < 0.001). However, rates of miscarriage, pregnancies with ≥1 survivor, maternal complications, and adverse neonatal outcomes were comparable among the three groups.

CONCLUSIONS

In our experience, FR in DCTA triplets could reduce prematurity risk compared to EM, but it confers no survival advantage. Fetal reduction to singletons may result in more favorable outcomes than those reduced to dichorionic twins.