JUMODA, a prospective study sponsored by the Paris public hospitals (AP–HP) and conducted between 2014 and 2015 by teams of researchers and clinicians from Inserm, Université Paris Descartes and AP–HP, has shed new light on the mode of delivering twins.

According to the coordinators of JUMODA (“MOde D’Accouchement des JUmeaux”), Professors Thomas Schmitz and François Goffinet, vaginal delivery is associated with decreased neonatal morbidity and mortality rates for both twins.

These results were published in the June issue of the journal Obstetrics & Gynecology.

While considerable progress has been made in recent years in perinatal healthcare, carrying and giving birth to twins are still high–risk situations. Indeed, sometimes serious complications can arise in both mother and children during pregnancy (hypertension, delayed growth, premature birth) and during the birth itself – especially that of the second twin (placental abruption, poor umbilical cord positioning, brutal uterine contractions during labor, etc.). Whereas the French neonatal mortality rate (death within 27 days of birth) is 2.3 per 1,000 live births for singletons (according to an Inserm study from 2013), it is 5 to 10 times higher for twins.

Until very recently, the practices of some French obstetricians were guided by the results of Anglo–Saxon retrospective studies that went against vaginal delivery in twin pregnancies, and particularly that of the second twin. In these studies, second twins enjoyed better neonatal health following Cesarean section than following vaginal delivery. Such data have contributed to the increased rate of Cesarean sections performed in France in this population over the past 20 years, and which in 2010 was 45%.

According to Prof. Schmitz, the methods of delivery, which differ considerably between France and Anglo–Saxon countries, may indeed be behind certain complications. It was therefore necessary to rigorously evaluate the obstetric practices involved in delivering twin pregnancies in France.

JUMODA, which stands for “Etude prospective comparative nationale sur le MODe D’Accouchement des femmes enceintes de JUmeaux” (national prospective and comparative study on the mode of delivery of twins), was initiated in 2014 by researchers from CRESS –Inserm/Université Paris Descartes/Paris public hospitals (AP–HP)– and coordinated by Professors Schmitz and Goffinet. Its objective was to measure the neonatal morbidity and mortality of twins, according to the planned mode of delivery (vaginal or Cesarean). To achieve this objective, the teams analyzed twin births in 176 French maternity units between February 2014 and March 2015. Approximately 8,800 women were enrolled, representing 75% of the total number of twin births in France during that period.

All in all, the study has shown that, in France, out of those women with twin pregnancies in the participating maternity units, 75% had an attempted vaginal delivery and 25% a planned Cesarean section. Most importantly, the attempted vaginal deliveries were associated with a low neonatal morbidity and mortality rate when the first baby was in the head–down position. For the first time, this rate of complications was even reported as being higher after a planned Cesarean section than after attempted vaginal delivery for children born at between 32 and 37 weeks.

In addition to avoiding the surgical and psychological complications associated with Cesarean sections, vaginal delivery may also – thanks to the fetus coming into contact with the mother’s vaginal bacteria – trigger a number of protective immune mechanisms that are important for the child’s long–term health and development.