Effectiveness of timing strategies for delivery of monochorionic diamniotic twins

Timing of Delivery for Twins

The optimal gestational age for delivery of twin gestations balances the risk to the mother with the risks to the fetus and newborn. Primary considerations should include chorionicity and the presence or absence of other obstetrical complications such as fetal growth restriction or hypertensive disorders of pregnancy. More than half of twin gestations will deliver preterm, and a significant portion will be due to spontaneous labor or medical indications, such that the timing of delivery for twins is typically less determined by the provider discretion. Future studies are needed to assist in clarifying the optimal timing for delivery of twin pregnancies.

The High-Risk Profile of Selective Growth Restriction in Monochorionic Twin Pregnancies

The present review aims to provide a critical appraisal of the sonographic diagnosis and follow-up and to evaluate the optimal clinical management of monochorionic twin pregnancies where one of the twins is complicated by selective fetal growth restriction (sFGR). The classification is based on the umbilical artery (UA) diastolic flow reflecting the outcome. If the sFGR twin has positive diastolic flow (Type I) then the prognosis is good, and it does not require close surveillance. Biweekly or weekly sonographic and Doppler surveillance and fetal monitoring are recommended strategies to detect unpredictable complications in type II and type III forms, which are defined by persistently absent/reverse end-diastolic flow (AREDF) or cyclically intermittent absent/reverse end-diastolic flow (iAREDF) in the umbilical waveforms, respectively. The latest forms are associated with an increased risk of unexpected fetal demise of the smaller twin and 10-20% risk of neurological injury in the larger twin in addition to the overall risk of prematurity. The clinical course can be affected by elective fetal therapy ('dichorinization' of the placenta with laser or selective fetal reduction) or elective delivery in the presence of severe fetal deterioration. The prediction of the clinical outcome in complicated cases of type II and III sFGR cases remains elusive. Novel routines in fetal and placental scans in order to predict neurological impairments and unexpected fetal death to optimize the delivery time-point are needed.

Induction of Labour. Guideline of the DGGG, OEGGG and SGGG (S2k, AWMF Registry No. 015-088, December 2020)

Aim The aim of this official guideline published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG) in cooperation with the Austrian Society of Gynaecology and Obstetrics (OEGGG) and the Swiss Society of Gynaecology and Obstetrics (SGGG) is to provide a consensus-based overview of the indications, methods and general management of induction of labour by evaluating the relevant literature. Methods This S2k guideline was developed using a structured consensus process which included representative members from various professions; the guideline was commissioned by the guidelines commission of the DGGG, OEGGG and SGGG. Recommendations The guideline provides recommendations on the indications, management, methods, monitoring and special situations occurring in the context of inducing labour.

Prospective risk of intrauterine death of monochorionic twins: update

OBJECTIVE

To calculate an updated prospective risk of fetal death in monochorionic-biamniotic (MCBA) twins.

STUDY DESIGN

We evaluated 520 MCBA twin pregnancies that had intensive prenatal surveillance and delivered in a single Portuguese referral center. The prospective risk of fetal death was calculated as the total number of deaths at the beginning of the gestational period divided by the number of continuing pregnancies at or beyond that period. Data were compared to the 2006 previous report.

RESULTS

Nearly 80% of the neonates weighed <2500 g, including 13.5% who weighed <1500 g. Half were born at <36 weeks, including 13.8% who were born at <32 weeks. The data indicate an increased IUFD rate over time - 16 fetal deaths per pregnancy (3.1%) and 22 IUFDs per fetus (2.1%). The rate of IUFD after 32-33 weeks, however, was halved (1/187 pregnancies and 1/365 fetuses, 0.5 and 0.3%, respectively).

CONCLUSION

Intensive prenatal surveillance might decrease the unexpected fetal death rates after 33 week's gestation and our data do not support elective preterm birth for uncomplicated MCBA twins.

Gestational age at delivery and neonatal outcome in uncomplicated twin pregnancies: what is the optimal gestational age for delivery according to chorionicity?

Objective

To investigate the neonatal outcome according to the gestational age at delivery and to determine the optimal timing for delivery in uncomplicated monochorionic and dichorionic twin pregnancies.

Methods

This is a retrospective cohort study of women with uncomplicated twin pregnancies delivered at or beyond 35 weeks of gestation from 1995 to 2013. The primary outcome was neonatal composite morbidity, which was defined as when either one or both twins have one or more of the followings: fetal death after 35 weeks gestation, admission to neonatal intensive care unit, mechanical ventilator requirement, respiratory distress syndrome and neonatal death. To determine the optimal gestational age for delivery according to chorionicity, we compared the neonatal composite morbidity rate between women who delivered and women who remained undelivered at each gestational week in both monochorionic and dichorionic twin pregnancies.

Results

A total of 697 twin pregnancies were included (171 monochorionic and 526 dichorionic twins). The neonatal composite morbidity rate significantly decreased with advancing gestational age at delivery and its nadir was observed at 38 and ≥39 weeks of gestation in monochorionic and dichorionic twins, respectively. However, the composite morbidity rate did not differ between women who delivered and women who remained undelivered ≥36 and ≥37 weeks in monochorionic and dichorionic twins, respectively.

Conclusion

Our data suggest that the optimal gestational age for delivery was at ≥36 and ≥37 weeks in uncomplicated monochorionic and dichorionic twin pregnancies, respectively.

The North American Fetal Therapy Network Consensus Statement: prenatal management of uncomplicated monochorionic gestations

Owing to vascular connections within a single placenta, monochorionic gestations present distinctive prenatal management challenges. Complications that can arise as a result of unbalanced hemodynamic exchange (twin-twin transfusion syndrome and twin anemia polycythemia sequence) and unequal placental sharing (selective fetal growth restriction) should be kept in mind while prenatal management is being planned. Because of unique monochorionic angioarchitecture, what happens to one twin can directly affect the other. Death of one twin can result in death or permanent disability of the co-twin. Early detection of these unique disease processes through frequent ultrasonographic surveillance may allow the opportunity for earlier referral, intervention, or both and potentially better outcomes. Therefore, monochorionic gestations should be managed differently than dichorionic gestations or singletons. The purpose of this document is to present in detail methods for monitoring and management of uncomplicated monochorionic gestations and to review the evidence for the roles of these methods for detection of complications in clinical practice. Finally, we present evidence-based and expert opinion-supported recommendations developed by the North American Fetal Therapy Network for the diagnosis, surveillance, and delivery of uncomplicated monochorionic gestations.

A population-based cohort study of stillbirth among twins in Lusaka, Zambia

OBJECTIVE

To determine rates of stillbirth and the associated risk factors for stillbirth among twins delivered in Lusaka, Zambia.

METHODS

A retrospective cohort analysis was conducted of singletons and twins delivered at 26 public sector facilities between February 1, 2006, and May 31, 2013. Data were obtained from the Zambian Electronic Perinatal Record System. Risk of stillbirth was estimated using logistic regression.

RESULTS

Overall, 260 657 singletons and 4021 twin pairs were included. There were 5105 stillbirths; 317 twins were stillborn. The crude stillbirth rate for twins was 39.4 per 1000 births (95% confidence interval [CI] 35.2-43.7) whereas the rate for singletons was 18.4 per 1000 births (95% CI 17.9-18.9; P<0.001). Factors associated with stillbirth among twins were increased interval between delivery (>60 minutes), low birth weight (<2500 g), birth order (being the second-born), and difference in birth weights (>30% discordance).

CONCLUSION

Twins were at an increased risk of stillbirth. Improved understanding of factors associated with stillbirth in this population could help to improve perinatal outcomes globally.

Clinical factors affecting the timing of delivery in twin pregnancies

OBJECTIVE

To investigate clinical factors affecting the timing of delivery in twin pregnancies in order to minimize perinatal complications.

METHODS

A retrospective study involved 163 twin pregnancies delivered from January 2006 to September 2011 at Gachon University Gil Medical Center. These cases were divided into three groups based on the delivery timing: less than 32 weeks' gestation (group A), between 32 and 35+6 weeks' gestation (group B), and over 36 weeks' gestation (group C). Clinical factors including maternal age, parity, presence of premature uterine contraction, presence of premature rupture of membrane, white blood cell, high sensitive C-reactive protein level, cervical dilatation, maternal complication, chorionicity, twin specific complication, and perinatal complication were analyzed for each group.

RESULTS

In group B, the timing of delivery was postponed for 14 days or more from the time of admission, and there were fewer numbers of babies with low Apgar score at birth compared with other groups. The frequency of uterine contraction (P<0.001), presence of premature rupture of membranes (P=0.017), dilatation of cervix (P<0.001), increased white blood cell and high sensitive C-reactive protein levels (P=0.002, P<0.001) were important clinical factors during decision making process of delivery timing in twin pregnancies. Twin specific fetal conditions, such as twin-twin transfusion syndrome and discordant growth (over 25% or more) were shown more frequently in group A. However, there were no significant statistical differences among three groups (P=0.06, P=0.14).

CONCLUSION

Proper management for preventing premature contraction and inflammation can be essential in twin pregnancies until 32 weeks' gestation, and may decrease maternal and perinatal complications.

Abdominal delivery in the intact amniotic sac in twin pregnancy

OBJECTIVE

There has been an increasing trend for Caesarean deliveries in twin pregnancies over the last decades; preferred mode of delivery is still unclear. The article presents the mode of twin delivery within intact amniotic sac.

METHODS

The intrapartum courses in 70 matched twin pairs extracted by Caesarean section were analysed. Neonates were distributed to two groups - main (delivered "en caul") and control (delivered by conventional Caesarean section) groups, and subdivided according to gestational age at the time of delivery: 28-30 weeks, 31-33 weeks and 34-37 weeks. Neonates delivered first and second were matched by pairs.

RESULTS

The duration of Caesarean section was higher in the main group (delivered "en caul"). Apgar score at 5-th min depend on the gestational age at birth and was higher in main group. Mechanical ventilation term and length of hospital stay were lower in main group. Postnatal neurological examination showed lower incidence of brain damage in the main group. During the first year of life, neonates extracted within intact amniotic sac showed lower morbidity rate. This was correct also for pairs of neonates matched by delivery order.

CONCLUSIONS

Presented method improves neonates' Apgar score, reduces the need for resuscitation and influence of intrapartum negative factors. The length of hospital stay and hospitalisation rate for the first year of life were also lower in neonates delivered "en caul", providing an economical benefit.

The cost-effectiveness of a trial of labor accrues with multiple subsequent vaginal deliveries

OBJECTIVE

The purpose of this study was to estimate costs and outcomes of subsequent trials of labor after cesarean delivery (TOLAC) compared with elective repeat cesarean deliveries (ERCD).

STUDY DESIGN

To compare TOLAC and ERCD, maternal and neonatal decision analytic models were built for each hypothetic subsequent delivery. We assumed that only women without previa would undergo TOLAC for their second delivery, that women with successful TOLAC would desire future TOLAC, and that women who chose ERCD would undergo subsequent ERCD. Main outcome measures were maternal and neonatal mortality and morbidity rates, direct costs, and quality-adjusted life years. Values were derived from the literature. One-way and Monte-Carlo sensitivity analyses were performed.

RESULTS

TOLAC was less costly and more effective for most models. A progression of decreasing incremental cost and increasing incremental effectiveness of TOLAC was found for maternal outcomes with increasing numbers of subsequent deliveries. This progression was also displayed among neonatal outcomes and was most prominent when neonatal and maternal outcomes were combined, with an incremental cost and effectiveness of -$4700.00 and .073, respectively, for the sixth delivery. Net-benefit analysis showed an increase in the benefit of TOLAC with successive deliveries for all outcomes. The maternal model of the second delivery was sensitive to cost of delivery and emergent cesarean delivery. Successive maternal models became more robust, with the models of the third-sixth deliveries sensitive only to cost of delivery. Neonatal models were not sensitive to any variables.

CONCLUSION

Although nearly equally effective relative to ERCD for the second delivery, TOLAC becomes less costly and more effective with subsequent deliveries.