Pregnancy and obstetric outcomes of dichorionic triamniotic triplet pregnancies with selective foetal reduction after assisted reproductive technology

BACKGROUND

It is generally beneficial and recommended that dichorionic triamniotic (DCTA) triplet pregnancies be reduced to monochorionic (MC) twin or singleton pregnancies after assisted reproductive technology (ART). However, some infertile couples still have a firm desire to retain twins. For this reason, the best foetal reduction strategies need to be available for infertile couples and clinicians. Given that data on the elective reduction of DCTA triplet pregnancies to twin pregnancies are scarce, we investigated the outcomes of elective reduction of DCTA triplet pregnancies through the retrospective analysis of previous data.

METHOD

Patients with DCTA triplet pregnancies who underwent elective foetal reduction between January 2012 and June 2020 were recruited. A total of 67 eligible patients with DCTA triplet pregnancies were divided into two groups: a DCTA-to-dichorionic diamniotic (DCDA) twin group (n = 38) and a DCTA-to-monochorionic diamniotic (MCDA) twin group (n = 29); the basic clinical data of the two groups were collected for comparison.

RESULTS

Compared with the DCDA-to-MCDA twin group, the DCTA-to-DCDA twin group had lower rates of complete miscarriage (7.89% versus 31.03%, p = 0.014), early complete miscarriage (5.26% versus 24.14%, p = 0.034), late preterm birth (25.71% versus 65.00%, p = 0.009) and very low birth weight (0 versus 11.11%, p = 0.025). In addition, the DCTA-to-DCDA twin group had higher rates of full-term delivery (65.71% versus 25.00%, p = 0.005), survival (92.11% versus 68.97%, p = 0.023), and taking the babies home (92.11% versus 68.97%, p = 0.023) than did the DCTA-to-MCDA twin group. In terms of neonatal outcomes, a significantly greater gestational age (38.06 ± 2.39 versus 36.28 ± 2.30, p = 0.009), average birth weight (3020.77 ± 497.33 versus 2401.39 ± 570.48, p < 0.001), weight of twins (2746.47 ± 339.64 versus 2251.56 ± 391.26, p < 0.001), weight of the larger neonate (2832.94 ± 320.58 versus 2376.25 ± 349.95, p < 0.001) and weight of the smaller neonate (2660.00 ± 345.34 versus 2126.88 ± 400.93, p < 0.001) was observed in the DCTA-to-DCDA twin group compared to the DCTA-to-MCDA twin group.

CONCLUSION

The DCTA-to-DCDA twin group had better pregnancy and neonatal outcomes than the DCTA-to-MCDA twin group. This reduction approach may be beneficial for patients with dichorionic triamniotic triplet pregnancies who have a strong desire to have DCDA twins.

Retrospective validation of 11-13 weeks' gestation ultrasound characteristics as predictive tools for twin-twin transfusion syndrome and selective intrauterine growth restriction in monochorionic diamniotic twin pregnancies

Background

Twin to twin transfusion syndrome (TTTS) is a serious syndrome that can affect twin pregnancies involving a single placenta, impacts some of twin gestations with monochorionic diamniotic (MCDA) placentas. We validated the ultrasound characteristics of 11–13 weeks’ gestation to predict TTTS and selective intrauterine growth restriction (sIUGR) in MCDA pregnancies.

Methods

We retrospectively included all of the MCDA twin pregnancies with ultrasound characteristics, including the crown-rump length (CRL), ductus venosus pulsatility index for veins (DV PIV), and nuchal translucency (NT) thickness, at 11–13 weeks’ gestation, followed by mean difference and discordance comparison. Receiver operating characteristic (ROC) curves were constructed for the comparison of values of these predictive markers for identification of MCDA pregnancies with high-risk of adverse outcomes.

Results

A total of 98 MCDA pregnancies were included in this study. Among the 98, 34 (34.7%) developed sIUGR, whereas 10 (10.2%) expressed TTTS. Significant differences in NT discordance were found among the normal, sIUGR, and TTTS groups; moreover, a significant difference was found between pregnancies with normal outcomes and sIUGR (P<0.001), normal and TTTS (P<0.001), and sIUGR and TTTS (P<0.001). Difference in NT was determined to be the best predictive marker for sIUGR [area under the curve (AUC) =0.769; 95% confidence interval (CI): 0.591 to 0.992], and NT discordance was considered the best predictive marker for TTTS (AUC =0.802; 95% CI: 0.485 to 0.936).

Conclusions

Significant differences in NT discordance were found between the normal, sIUGR, and TTTS groups, while NT difference and NT discordance were identified as predictive markers for sIUGR and TTTS, respectively.