Perinatal outcomes of monochorionic triplet pregnancies: multicenter cohort study

• Published in: Ultrasound in obstetrics & gynecology
• Main Authors: Sileo, F G, Accurti, V, Baschat, A, Binder, J, Carreras, E, Chianchiano, N, Cruz-Martinez, R, D'Antonio, F, Gielchinsky, Y, Hecher, K, Johnson, A, Lopriore, E, Massoud, M, Nørgaard, L N, Papaioannou, G, Prefumo, F, Salsi, G, Simões, T, Umstad, M, Vavilala, S, Yinon, Y, Khalil, A
• Format: Journal Article
• Language: English
• Published: England 19-05-2023
• Subjects: triamniotic; monochorionic; triplet; growth restriction; miscarriage; outcomes; TAPS; pregnancy; TTTS; multiple
• ISSN: 1469-0705

Monochorionic triplet pregnancies are extremely rare and information on these pregnancies and their complications are limited. We aimed to investigate the risk of early and late pregnancy complications, perinatal outcomes, and the timing and methods of fetal intervention in monochorionic triplet pregnancies.
This was a multicenter retrospective cohort study including monochorionic triamniotic (MCTA) triplet pregnancies. The exclusion criteria were twins, or multiple pregnancies with higher order than triplets (e.g. quadruplets, quintuplets), and dichorionic or trichorionic triplet pregnancies. Data on maternal age, mode of conception, diagnosis of major fetal structural anomalies or aneuploidy, gestational age (GA) at diagnosis of anomalies, twin to twin transfusion syndrome (TTTS), twin anemia polycythemia syndrome (TAPS), twin reversed arterial perfusion sequence (TRAP), or selective fetal growth restriction (sFGR) were ascertained from the patient records. Data on antenatal interventions were collected, including selective (fetal) reduction (3 to 2 or 3 to 1), laser surgery, or any active fetal intervention (including amniodrainage). Finally, perinatal outcomes included livebirth, intrauterine demise (IUD), neonatal death (NND), perinatal death (PND) and termination of pregnancy (TOP). Neonatal data such as GA at birth, birthweight, neonatal intensive care unit (NICU) admission, and neonatal morbidity were also collected.
In our cohort of MCTA triplet pregnancies (n=153 after excluding early miscarriages, TOP and loss to follow-up), the majority (90%) were managed expectantly. The incidence of fetal abnormalities and TRAP was 13.7% and 5.2%, respectively. The most common antenatal complication related to chorionicity was TTTS, which complicated just over a quarter (27.6%) of the pregnancies, followed by sFGR (16.4%), while TAPS (both spontaneous and post-laser) occurred in only 3.3%; no antenatal complication was recorded in 49.3% of pregnancies. Survival was largely associated with the development of these complications: 85.1%, 100% and 47.6% of pregnancies had at least one surviving newborn in those without antenatal complications, complicated by sFGR, or complicated by TTTS, respectively. The overall rates of preterm birth prior to 28 weeks and prior to 32 weeks' gestation were 14.5% and 49.2%, respectively.
MCTA triplet pregnancies represent a challenge in counseling, surveillance and management as monochorionicity-related complications occur in almost half of these pregnancies, which negatively impact their perinatal outcomes. This article is protected by copyright. All rights reserved.