Mode of delivery of Finnish dichorionic and monochorionic-diamniotic twins: A retrospective observational study including a risk score for intrapartum cesarean birth

Background and Aims

Trial of labor is considered safe also among twins, yet nearly 50% are born via cesarean section in Finland. While planned cesarean births have declined among twins, intrapartum cesarean deliveries have risen, postulating evaluation of criteria for trial of labor. The objective of this study was to create an outline of the mode of delivery of dichorionic and monochorionic-diamniotic Finnish twins. By evaluating risk factors for intrapartum cesarean delivery (CD), we aimed at creating a risk score for intrapartum cesarean birth for twins.

Methods

A retrospective observational study based on a cohort of dichorionic and monochorionic-diamniotic twin pregnancies considered as candidates for trial of labor in 2006, 2010, 2014, and 2018 (n = 720) was performed. Differences between parturients with vaginal delivery and intrapartum CD to identify potential risk factors for intrapartum CD were assessed. Logistic regression analysis (n = 707) was used to further define risk score points for recognized risk factors.

Results

A total of 23.8% (171/720, 95% confidence interval [CI] = 20.7-26.9) of parturients experienced intrapartum CD. Induction of labor, primiparity, fear of childbirth, artificial reproductive technology, higher maternal age, and other than cephalic/cephalic presentation independently associated with intrapartum CD. The achieved total risk score ranged from 0 to 13 points with significantly higher points among the CD group (6.61 vs. 4.42, p < 0.001). Using ≥8 points as a cut-off, 51.4% (56/109) were delivered by intrapartum CD (sensitivity = 33.73%, specificity = 90.20%, positive predictive value = 51.38%, negative predictive value = 81.61%). The total risk score had a fair predictive capability for intrapartum CD (area under the curve = 0.729, 95% CI = 0.685-0.773).

Conclusion

Fair-level risk stratification could be achieved with higher maternal age, primiparity, induction of labor, artificial reproductive technology, fear of childbirth, and other than cephalic/cephalic presentation increasing the risk. Parturients with low-risk score (0-7 points) appear to be the best candidates for trial of labor with acceptable CD rates in this group (18.4%).

Perinatal outcome of dichorionic and monochorionic-diamniotic Finnish twins: a historical cohort study

INTRODUCTION

Although the perinatal mortality of monochorionic twins has been reported to be higher, the role of chorionicity is debated and data from Finland are still lacking. To examine the effect of chorionicity on the main outcome measures, perinatal and neonatal mortality and neonatal morbidity of Finnish twins, a comprehensive population-based historical cohort study was performed at Helsinki University Hospitals.

MATERIAL AND METHODS

All 1034 dichorionic and monochorionic-diamniotic twin pregnancies managed at Helsinki University Hospital area during 2006, 2010, 2014 and 2018 were collected from patient databases. Information on chorionicity was retrieved from ultrasound reports and all relevant clinical information from patient records. Differences in perinatal and neonatal mortality and neonatal morbidity were analyzed by performing group comparisons between the twins and chorionicity. The role of chorionicity was also assessed in logistic regression analyses.

RESULTS

There were 1034 dichorionic-diamniotic (DCDA, n = 789, 76.3%, 95% confidence interval [CI] 73.6-78.9) and monochorionic-diamniotic (MCDA, n = 245, 23.7%, 95% CI 21.4-26.0) twin pregnancies during the studied years. Most (n = 580, 56.1%, 95% CI 52.8-59.2) twins were born at term, but 151 (61.6%, 95% CI 55.8-67.3) of MCDA twins were preterm and had lower birthweight and Apgar scores and higher risk of death of one twin. Perinatal and neonatal mortality did not differ between twins A and B, but the immediate outcome of twin B was worse, with lower arterial pH and Apgar scores and increased need of neonatal intensive care unit treatment.

CONCLUSIONS

Chorionicity contributes to the perinatal and neonatal outcome in favor of dichorionic twins. This disadvantage of MCDA twinning is likely explained by earlier gestational age at birth and inequal placental sharing. Irrespective of chorionicity, twin B faces more complications.

Correction to: Maternal complications in twin pregnancies in Finland during 1987–2014: a retrospective study

An amendment to this paper has been published and can be accessed via the original article.

Maternal complications in twin pregnancies in Finland during 1987-2014: a retrospective study

BACKGROUND

To investigate the trends and changes in the incidence and overall outcome of twin pregnancies in Finland, a retrospective study was conducted with emphasis on maternal complications, covering a 28-year study period.

METHODS

All 23,498 twin pregnancies with 46,363 live born and 633 stillborn children in Finland during 1987-2014 were included in the study. Data were collected from the national Medical Birth Register and the Care Register on Hospital Care (Finnish Institute for Health and Welfare, Finland) regarding the parturients' characteristics and incidences of several pregnancy and childbirth complications. The incidences of twin pregnancies and maternal complications during pregnancy and childbirth are the main outcome measures of the study. The results are expressed in percentages, means, medians, ranges and standard deviations (SD), when appropriate.

RESULTS

Twins comprised 1.4% of all births in Finland in 1987-2014. Parturients' mean age has remained stable, but the share of over 35 year-old parturients is increasing. The incidences of pre-eclampsia, intrahepatic cholestasis of pregnancy, gestational diabetes and postpartum haemorrhage have risen during the study period. Almost half (44.9%) of twins were born preterm, almost half via Caesarean section (47.1%), and 27.7% of twin labours were induced.

CONCLUSIONS

Several pregnancy complications increased during the study period. Advanced maternal age among twin parturients has risen, enhancing the risks for developing complications in a pregnancy already of a high-risk category, and predisposing to preterm delivery. National and international guidelines are necessary to improve the overall outcome of twin pregnancies.