Obstetric and perinatal outcomes following fetal death of a single twin in a biamniotic monochorionic pregnancy: case report and literature review

Abstract

BACKGROUND: Multiple gestations suggest an increased risk of perinatal mortality. Within these statistics, death of a single twin occurs in up to 6% of multiple pregnancies. The overall incidence after 20 weeks gestation (sdg) is estimated to be between 2.6% and 6.2% of all such pregnancies. Chorionicity, rather than zygosity, has been shown to influence the outcome of this complication, due to the placental angioarchitecture of the circulations in monochorionic pregnancies. Loss rates of up to 30-50% have been associated with monochorionic and monoamniotic pregnancies. If it occurs before 14 sdg, the embryo may disappear; between 14 and 20 sdg, the fetus is reduced in size and volume. And, if it occurs after 20 sdg, the fetus remains inside the uterus until the end of gestation.

CLINICAL CASE: 18-year-old female, who attended an obstetric check-up with an ultrasonographic report of a biamniotic monochorionic twin pregnancy of 30.4 sdg, and death of one of the twins. After demonstrating hemodynamic stability of the surviving fetus, as well as maternal stability, it was decided to hospitalize her for close monitoring. One week later she developed preterm labor and it was decided to terminate the pregnancy urgently. A male newborn was obtained with a gestational age suggestive of 32 sdg, with respiratory distress and required hospitalization for close monitoring of the premature newborn. Mother was discharged at 48 hours, never developed disseminated intravascular coagulation (DIC) and the newborn remained in hospital for approximately 3 and a half weeks until he was discharged due to adequate adaptation. No neurologic or other organ or system involvement was ever demonstrated.

CONCLUSIONS: The most important factors when considering the risk to the surviving twin are the gestational age at which the death of the other fetus occurs, and chorionicity. Management should include serial and scheduled ultrasounds for growth. Peripheral arterial/venous and intracardiac Doppler studies and MRI at least 3 weeks after fetal death to look for changes in the brain of the surviving twin. Although there are case reports of conservative management, close monitoring of maternal DIC data, as well as normoinsert placental abruption, is necessary.