AT ACOG 2016
WASHINGTON (FRONTLINE MEDICAL NEWS) – Monoamniotic-monochorionic twins can be safely delivered vaginally, with low rates of adverse fetal or maternal outcomes.
Despite seeing cord entanglement in almost every case, a small retrospective study found no safety signals that support pre-emptive cesarean deliveries for this class of twins, Dr. Meena Khandelwal said at the annual meeting of the American College of Obstetricians and Gynecologists. In fact, vaginal delivery was associated with a significantly lower rate of intracranial hemorrhage, which occurred in 27% of the cesarean-delivered infants and none of the infants delivered vaginally.
Dr. Khandelwal and her colleagues won third prize for the study among the 2016 ACOG research awards.
In 2014, an ACOG technical bulletin advised cesarean delivery for all monoamniotic twins, a recommendation in line with those in Canada and France. But the ACOG advice was based on level C evidence, said Dr. Khandelwal of Cooper University Hospital, Camden, N.J.
“These recommendations are fear based, not fact based,” she said. “It is felt that the risk of entrapment is too great. But cord entanglement is seen in virtually all of these cases, and a large study recently found that it contributed nothing to morbidity or mortality in the fetuses.”
That study, published in 2013, reviewed 114 monoamniotic twin pregnancies (228 fetuses). There were 26 perinatal fetal deaths, only two of which were related to cord entanglement. The author found no significant difference in mortality between the fetuses with entanglement (82) and those without ( Ultrasound Obstet Gynecol. 2013 Feb;41:131-5 ).
Dr. Khandelwal conducted her own retrospective study of 29 sets of monoamniotic-monochorionic twins that were born vaginally or by cesarean delivery at two tertiary care centers in New Jersey, from 1997 to 2014. Her cohort comprised 10 pregnancies at Thomas Jefferson Hospital, Philadelphia, which only offers cesarean delivery for these cases, and 19 at Cooper University Hospital, which offers the option of vaginal delivery if the first twin is in cephalic position, the fetal heart rate is reactive at the onset of labor, and there are no contraindications to vaginal delivery.
Cooper also manages these pregnancies on an outpatient basis with vaginal delivery offered from 32 to 36 weeks. Thomas Jefferson admits them to the antepartum unit from 24 to 28 weeks and offers cesarean delivery from 32 to36 weeks.
The mean age of the women in the series was 29 years; median parity was one. Almost half of the women having a planned cesarean had a history of a prior cesarean; none of the women who planned a vaginal delivery had a prior cesarean delivery.
Of the 19 women offered vaginal delivery, 14 accepted. Of these, 10 (71%) delivered both twins vaginally. The mean time between the twin deliveries was 3 minutes. Cesarean delivery was necessary for four neonates in the planned vaginal delivery group: three due to concerning heart rate tracings and one because of a failed internal version of a transverse presentation of a second twin.
Three fetuses died before birth – one in the planned vaginal delivery group (7%) and two in the planned cesarean delivery group (13%). There was one post partum hemorrhage, which occurred in the planned cesarean group. There were no cases of chorioamnionitis. Birth weight was similar (about 1,800 grams). Cords were entangled in 100% of the vaginal delivery group and 93% of the cesarean group. Apgar at 5 minutes was 6.6 in the vaginal delivery group and 8.3 in the cesarean group.
Respiratory distress syndrome was significantly more common among the planned cesarean group (86% vs. 65%). There were eight cases of intracerebral hemorrhage in that group and none in the planned vaginal delivery group (28% vs. 0%). These were all grade 1 or 2 bleeds. There were no neonatal deaths.
The length of stay was shorter in the planned vaginal delivery group, but not significantly so (median 18 vs. 25 days).
“This is a small study but it does add valuable data on the safety of vaginal delivery in [monoamniotic-monochorionic] twins,” Dr. Khandelwal said. “Vaginal delivery can be considered a safe option in tertiary care centers.
She reported having no financial disclosures.