122: Timing of delivery of uncomplicated monochorionic monoamniotic twins

OBJECTIVE: To determine the impact of routine hospitalization of monoamniotic twins for fetal monitoring on perinatal survival and neonatal morbidity; and to determinate the fetal and neonatal death rate according to gestational age in non-anomalous monoamniotic twins who reached viability. STUDY DESIGN: The MONOMONO study was a multinational, cohort study. Clinical records of all consecutive monochorionic monoamniotic twin pregnancies, who were referred to 22 University Hospitals in Italy, United States, United Kingdom, and Spain, were included in the study. Management of monoamniotic twins was different in the different included centers. In 11 centers all monoamniotic twins were routinely managed as inpatient. In 11 centers all monoamniotic twins were routinely managed as outpatient. In both group delivery was scheduled via planned cesarean delivery usually at 32 0/7 - 34 6/7 weeks. The primary outcome was intrauterine fetal death comparing inpatient versus outpatient group. RESULTS: 270 non-anomalous uncomplicated monoamniotic twin gestations (540 fetuses) were included. Of them, 150 (55.6%) were managed as inpatient and 120 (44.4%) were managed as outpatient. Twins managed inpatient had a significantly lower intrauterine fetal death (3.3% vs 10.8%; aOR 0.27, 95% CI 0.07 to 0.94), neonatal death (0.7% vs 4.2%: aOR 0.19, 95% CI 0.10 to 0.84), and perinatal death (4.0% vs 15.0%; aOR 0.24, 95% CI 0.09 to 0.62), and their babies stayed in NICU about 10 days less (MD -10.70 days, 95% CI -14.33 to -7.07). Maternal LOS in the hospital was 42.1 days in the inpatient group, and 7.4 days in the outpatient group (MD 34.70 days, 95% CI 31.31 to 38.09). From 32 0/7 to 35 6/7 weeks, no fetal death or neonatal death in either group was recorded. CONCLUSION: On the basis of these data, we recommend inpatient management of monoamniotic twin pregnancies with NST 2-3 times daily starting from around 26 weeks of gestations. Our data also suggested that in case of non-anomalous uncomplicated monoamniotic twins the fetal death rate and the neonatal death rate after 31 6/7 weeks do not increase even up to 35 6/7 weeks, and therefore planned cesarean delivery 33 0/6 - 34 6/7 is a reasonable alternative to discuss with the patient.