Management of monoamniotic twin pregnancies: Where, when, how?

Clinical Outcome of Monochorionic Diamniotic Twins with Intrauterine Growth Restriction

OBJECTIVE

This study investigated the clinical outcome of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR).

STUDY DESIGN

International Peace Maternal and Child Health Hospital of Shanghai ultrasound database was investigated to identify all MCDA delivered from January 2013 to December 2017. After identifying 43 pairs of MCDA twins with sIUGR and 282 pairs of normal MCDA twins, we compared clinical outcomes between the two groups.

RESULTS

Compared with normal twins, sIUGR fetuses had significantly shorter gestational age at delivery, smaller average birth weight of both twins, more significant intertwin difference in birth weight, lower Apgar scores, and higher intrauterine fetal demise (IUFD) rate, and smaller placental weight. The rate of abnormal umbilical cord insertions and abnormal blood flow in the ductus venosus (DV) and middle cerebral artery (MCA) is significantly higher in the sIUGR group. In addition, the subtype analysis of sIUGR groups indicated the poorest outcomes in type II with no significant difference between type I and III.

CONCLUSION

MCDA twins with sIUGR generally exhibited limited clinical outcomes than normal MCDA twins. These limitations are mainly associated with abnormal umbilical cord insertions and blood flow in the DV and MCA. Clinical outcomes differed among the three types of sIUGR, with type II having the worst prognosis and the highest IUFD rate.

KEY POINTS

· sIUGR generally exhibited limited clinical outcomes than normal MCDA twins.. · These limitations are mainly associated with blood flow of the DV and MCA.. · sIUGR with type II has the worst prognosis and the highest IUFD rate..

Outcomes of vertex-vertex vs. vertex-breech presentation in twin pregnancy after vaginal delivery in China

OBJECTIVE

To compare the maternal and neonatal outcomes of twin pregnancies between vertex and nonvertex presentations of the second twin in vaginal delivery.

METHODS

In this unicentric retrospective cohort study, we collected data from 213 cases of vaginal twin deliveries from January 2016 to July 2020. Participants were divided into the vertex-vertex presentation group (VV) and vertex-breech presentation group (VB). Data on maternal and neonatal outcomes were compared between groups.

RESULTS

Among the 213 mothers and 426 infants (213 twin pairs), there were 140 women in the VV group and 73 women in the VB group (65.73% vs. 34.27%). Infants in the VB group had a higher incidence of admission to NICU (51.43% vs. 68.49%, p = 0.017), lower 1-min (11.43% vs. 28.77%, p < 0.001) and 5-minute Apgar scores (1.43% vs. 4.11%, p = 0.043) for the second twin. However, after the adjustment for sex of the twin, birth weight, chorionicity, and gestational age, the greater risk of admission to NICU and low 5-min Apgar score was no longer significantly different.

CONCLUSION

VB twins are at no greater overall risk of a poor outcome due to breech presentation in the second twin. However, the presentation of the second fetus represents a risk factor for a low 1-min Apgar score. Obstetricians and midwives should consider appropriate interventions for second twins who present breech versus vertex.

[Comparison of foetal and neonatal mortality of monochorionic monoamniotic and monochorionic biamniotic twin pregnancies]

OBJECTIVES

To compare the mortality of monochorionic-monoamniotic (MCMA) and monochorionic-biamniotic (MCBA) twin pregnancies, from 14weeks of gestation to 28th day of life, before and after exclusion of major congenital malformations.

METHODS

We conducted a retrospective cohort study in two level 3 maternity units of the Hospices civils de Lyon (France) including all patients with a monochorionic twin pregnancy between January 2013 and December 2020. We excluded TRAP sequences and conjoined twins.

RESULTS

A total of 38 MCMA and 658 MCBA pregnancies were included. We showed an increase in overall mortality in the MCMA group compared to the MCBA group (31.6% versus 16.4%, P=0.03) even after exclusion of major congenital malformations (20.3% versus 9.5%, P=0.01). The main cause of mortality found in the MCMA group was the occurrence of unexpected IUGR.

CONCLUSIONS

MCMA pregnancies have a higher foetal and neonatal mortality rate than MCBA pregnancies even after exclusion of congenital malformations related to the occurrence of unexpected MFIU.

Excellent perinatal outcome of monoamniotic twin pregnancy with timely diagnosis and optimal management - a retrospective cohort study

OBJECTIVES

Monoamniotic twins represent a high-risk pregnancy requiring intense follow-up, elective birth and careful consideration of the mode and timing of delivery. We conducted this study to evaluate the perinatal and neonatal outcomes of monoamniotic twin pregnancies in the largest tertiary hospital in Finland.

METHODS

This was a retrospective cohort study including all monoamniotic twin pregnancies during a 17-year period (2002-2018) managed in Helsinki University Hospital. Data on mothers and children were collected from patient files. Chorionicity and amnionicity were defined in first-trimester ultrasound screening.

RESULTS

There were altogether 31 monoamniotic twin pregnancies during the study period, including four cases of conjoined twins which all underwent termination of pregnancy, and three miscarriages. In the remaining 24 pregnancies that continued past 24 weeks of gestation there was 97.9% survival (one intrauterine death). Three pregnancies were complicated with twin-to-twin transfusion syndrome. All children were delivered by cesarean section with a mean gestational age of 32 + 5 weeks (27 + 1-34 + 2 weeks). Respiratory distress syndrome (RDS) was observed in 57% (27/47) of neonates and grade I-II intraventricular haemorrhage (IVH) in 6.3% (3/47) of neonates. There were no neonatal deaths and no maternal complications.

CONCLUSIONS

Monoamniotic twinning is a rare form of pregnancy and carries risks for perinatal and neonatal complications. With timely diagnosis, close monitoring in specialized feto-maternal unit and elective delivery at 32-34 weeks the outcome is usually excellent.