Clonal dynamics of monozygotic twinning in early human embryogenesis

Monochorionic triplet gestation after in vitro fertilization using donor oocytes: Case report and review

When is the actual splitting time of the embryo to develop a monozygotic dichorionic diamniotic (DD) twins following a single embryo transfer?

Monozygotic triplet pregnancy following egg donation and transfer of single frozen-thawed embryo

Background Monochorionic twins have higher perinatal morbidity and mortality than dichorionic twins. However, there is conflicting data on outcomes of uncomplicated monochorionic twins. Purpose of the Study The aim of this study is to compare the outcomes of apparently uncomplicated monochorionic twins to dichorionic twins. Methods This is a prospective study conducted from August 2019 to December 2020 at a specialized twin clinic. All twins, whose chorionicity was determined before 14 weeks with two live fetuses at 24 weeks, were recruited. Complicated monochorionic diamniotic (MCDA) twins with twin-to-twin transfusion syndrome, twin anemia polycythemia syndrome, selective fetal growth restriction before 24 weeks and single or double fetal demise before 24 weeks were excluded. Other exclusion criteria were major congenital and chromosomal abnormalities, higher order multiples, monoamniotic twins, and twins with undetermined chorionicity antenatally. Both the groups were followed till delivery and neonates followed till 28 days. Maternal and neonatal outcomes were studied and compared. Results One-hundred forty-eight mothers with dichorionic diamniotic (DCDA) and 74 with uncomplicated MCDA were studied. Mean gestational age at delivery was 35 weeks in both the groups. Maternal, fetal, and neonatal morbidities were similar in both, except early onset preeclampsia that was higher in the DCDA group. Prospective risk of stillbirth for DCDA and MCDA after 24 weeks was 1.35 and 4.05%, respectively. Prospective risk of stillbirth for DCDA and MCDA after 30 weeks was 1.49 and 0%, respectively. Conclusion The maternal and perinatal outcomes in uncomplicated MCDA twins are similar to DCDA twins. Prospective risk of stillbirth after 30 weeks is extremely low. Hence, uncomplicated MCDA twins should not be delivered electively before 36 weeks.

Introduction: Monochorionic monoamniotic (MCMA) twins are rare, and information is lacking on pregnancy outcomes from the first trimester onward. This study compares the pregnancy and neonatal outcomes between MCMA and monochorionic diamniotic (MCDA) twin pregnancies from the first trimester onward. We also report on the outcomes of MCMA twin pregnancies continuing after 28 weeks and on the neurodevelopmental outcomes of MCMA twins. Methods: A retrospective single-center cohort study of MCMA and MCDA twin pregnancies followed from the first trimester with a fortnightly ultrasound scan. We excluded pregnancies with a major anomaly diagnosed on the first-trimester ultrasound scan. MCMA twin pregnancies were offered inpatient monitoring from 28 weeks onward, and an elective cesarean section was advised between 32 and 33 weeks. MCDA pregnancies were managed as inpatients only if medically indicated, and an elective birth between 36 and 37 weeks was recommended. Results: We analyzed the outcomes of 52 MCMA and 671 MCDA twin pregnancies. In MCMA twins, the fetal and neonatal survival rate was 81/104 (78%) versus 1,192/1,342 (89%) in MCDA twins (p = 0.016). Double intrauterine demise (IUD) was more common in MA than in DA pairs (13% vs. 3%) (p = 0.002). No IUD occurred in the 40 MCMA pregnancies that continued after 28 weeks, but five women (13%) required an urgent cesarean section for fetal distress. Thirty-eight of 52 eligible infants (73%) underwent a neurodevelopmental assessment. Thirty-three (87%) had cognitive and motor development scores within normal limits. Four infants had mild cognitive or motor impairment, and one infant was diagnosed with spastic diplegia. Conclusion: MCMA twins are associated with decreased survival rates compared to MCDA due to increased rates of double IUD. After 28 weeks, about one in eight women required an urgent delivery for fetal distress. Most infants had normal neurodevelopmental outcomes.

Genetic evaluation for twin pregnancies using karyotyping and single nucleotide polymorphism array analysis

The rate of multiple pregnancies is showing a significant increase in Western countries. Twin gestations should be considered a high-risk condition because they are responsible for a disproportionate amount of overall perinatal morbidity and mortality. We used a specialised ultrasound protocol based on chorionicity to monitor 44 twin pregnancies (61% dichorionic diamniotic (DD) and 39% monochorionic diamniotic (MD)). Adverse pregnancy outcomes and pre-term deliveries were more common in MD pregnancies than in DD pregnancies; the rate of extreme pre-term delivery (< 32 weeks) was almost three-times higher in MD than in DD pregnancies (41% vs 15%) and perinatal complications were more frequent in MD than in DD pregnancies (59% vs 22%), but fetal anomalies were more frequent in DD than in MD pregnancies (30% vs 24%). Periodic ultrasound follow-up would predict the pregnancies that are at greater risk for fetal and neonatal complications and these should be monitored more closely.

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BackgroundTo evaluate the perinatal outcomes in women with selective termination using ultrasound-guided radiofrequency ablation (RFA).MethodsComplicated monochorionic (MC) twin pregnancies and multiple pregnancies with an indication for selective termination by ultrasound-guided coagulation of the umbilical cord with RFA under local anesthesia between July 2013 and Jan 2020 were reviewed. We analyzed the indications, gestational age at the time of the procedure, cycles of RFA, duration of the procedure, and perinatal outcome.ResultsThree hundred and thirteen patients were treated during this period. Seven of whom were lost of follow-up. The remaining 306 cases, including 266 pairs of monochorionic diamniotic (MCDA) twins (86.93%), two pairs of monoamniotic twins (0.65%), 30 dichorionic triamniotic (DCTA) triplets (1%), and three monochorionic triamniotic (MCTA) triplets (0.98%), were analyzed. Indications included twin-to-twin transfusion syndrome (TTTS) (n = 91), selective fetal growth restriction (sFGR) (n = 83), severe discordant structural malformation (n = 78), multifetal pregnancy reduction (MFPR) (n = 78), twin reverse arterial perfusion sequence (TRAPS) (n = 19), and twin anemia-polycythemia sequence (TAPS) (n = 3). Upon comparison of RFA performed before and after 20 weeks, the co-twin loss rate (20.9% vs. 21.5%), the incidence of preterm premature rupture of membranes (PPROM) within 24 h (1.5% vs. 1.2%), and the median gestational age at delivery [35.93 (28–38) weeks vs. 36 (28.54–38.14) weeks] were similar (p > 0.05).ConclusionsRFA is a reasonable option when indicated in multiple pregnancies and complicated monochorionic pregnancies. In our experience, the overall survival rate was 78.76% with RFA in selective feticide, and early treatment increases the likelihood of survival for the remaining fetus because the fetal loss rate is similar before and after 20 weeks.

Monozygotic twinning: A 5 year experience in a large IVF center doing blastocyst transfers on day 5

Monochorionic monoamniotic (MCMA) twins are rare but are associated with higher morbidity and mortality rates than monochorionic diamniotic (MCDA) twins. Although the prenatal prognosis of MCMA pregnancy has improved with advanced prenatal care, no consensus has been reached for the management for MCMA twins. Here, the authors report two cases of MCMA twin pregnancies diagnosed at 30 weeks of gestation and complicated with congenital heart disease, respectively, with a review of literature on MCMA twin pregnancies.

HIGHLIGHTS Monochorionic monoamniotic (MCMA) twin pregnancy has a significant risk of perinatal morbidity and mortality, including intrauterine fetal death (IUFD). The risk of prematurity, the risk of death due to MCMA complications, the availability of the NICU, also high costs on preterm care were factors in deciding to terminate the pregnancy. The ideal time to deliver monochorionic twins in order to reduce the risks of cord entanglement, growth discrepancies, and intrauterine fetal death is still a point of controversy. Early diagnosis, intensive antenatal monitoring, patient and family decision would contribute to antenatal mortality reduction. ABSTRACT Objectives: To present the management of monochorionic monoamniotic (MCMA) twin pregnancy. Case Report: Advanced prenatal treatment has improved the prognosis for Monochorionic Monoamniotic (MCMA) pregnancies; however, there is still no agreement on how to handle MCMA twins. The authors report 2 cases of monoamniotic monochorionic twin pregnancies. In the first case, a 30-years-old primi pregnant woman detected MCMA at 14 weeks of gestation; no complications related to MCMA were found; she planned delivery at 32 weeks, but one of the babies died in the womb at 31/32 weeks pregnant, a live baby born by cesarean section. The second case was a 36-year-old pregnant woman, on her third pregnancy, diagnosed with MCMA after 12 weeks of pregnancy, no complications related to MCMA, the baby was born at 32 weeks pregnant, and both babies survived. The management was the same in both cases, but different outcomes were obtained; in case 1, the baby died allegedly due to cord entanglement, which could not be detected during pregnancy.

Twins are a source of curiosity, both for the family and the scientific community. Genetic similarities between twins have been the preferred choice to study the heritability of traits. The fact that nature and nurture play a significant role in shaping one’s phenotype has prompted Geneticists to use twins as a proxy to address this fact. Based on the similarities, twins are of two types, monozygotic twins (MZ) and Dizygotic twins (DZ). Identical or monozygotic twins are formed when one fertilized egg (ovum), fertilized by one sperm, splits and develops into two embryos with precisely the same genetic information. The combined ratio of MZ and DZ to singleton delivery is approx 1: 100. On the other hand, fraternal or dizygotic twins are formed when two eggs (ova) are fertilized by two sperm and produce two genetically unique children in the same pregnancy. Monochorionic twins are genetically identical, sharing the same placenta. If more than two twins share the placenta, these are monochorionic multiples. Monochorionic twins occur in 0.3% of all pregnancies. Monozygotic (identical) twins share all their genes, while dizygotic (fraternal) twins only share about 50%. Hence, any similarity seen between identical twins when comparing the similarity between sets of fraternal twins for a trait or condition is most probablydue to genes rather than environment. TWIN REGISTRIESProgress in twin research worldwide is carried out by establishing Twin registries or consortia based on collaborations of several twin families. These registries are a rich source of materials for Twin research. It is much needed to establish such Twin registries in India. With its 1.5 Billion population, Indian Twin registries can be a source of materials for Twin Research for the whole world.

OC62 The impact of chorionicity and assisted reproductive therapies in obstetric and neonatal outcomes: a retrospective study in 1783 portuguese twins

We present a case report of a congenital malformation of the uropoetic tract in one of the monoamniotic twins. A 24-year-old primigravida with male monochorionic monoamniotic twins was dia-gnosed with congenital malformation in fetus A at 24 weeks of gestation. Ultrasound verified macrocystic dysplasia and contralateral renal agenesis. Planned caesarean section was performed after the observational management of the patient in the 34th gestational week. In fetus B, a physiological finding was confirmed on the postpartum ultrasonography. In fetus A, CT examination of the abdomen confirmed the finding of left kidney agenesis and polycystic degeneration of the right kidney. Exitus letalis was stated on the newborns 5th day. The occurrence of the described combination of congenital malformation in monoamniotic twins is rare. When dysplasia significantly affects the function of the parenchyma, renal agenesis with multicystic dysplasia of the other kidney is a condition incompatible with life. For the intrauterine survival of the affected fetus, the normal renal function of the twin was important and thus the normal volume of amniotic fluid was maintained. As a result, the fetus did not develop extrarenal symptoms of the Potter sequence in the described case - especially pulmonary hypoplasia and the newborn was able to ventilate spontaneously. The death was caused by the consequences of renal failure associated with anuria.