Twin–Twin Transfusion Syndrome Resulting in Single Intrauterine Fetal Death and Subsequent Neonatal Death of the Surviving Twin: A Case Report

Abstract

Background: Twin–twin transfusion syndrome (TTTS) is a serious complication of monochorionic twin pregnancies and may result in significant morbidity and mortality for both fetuses. Single intrauterine fetal death (sIUFD) in a monochorionic pregnancy is particularly concerning because vascular anastomoses between the twins may expose the surviving co-twin to acute hemodynamic compromise, neurological injury, or death. Early determination of chorionicity and structured surveillance of monochorionic twin pregnancies are therefore essential but may be challenging in resource-limited settings.
Case report: A 26-year-old gravida 3 para 1 woman with a twin pregnancy underwent a detailed anomaly scan at 26 weeks 0 days of gestation. An earlier first-trimester ultrasound had reportedly demonstrated both embryos within a single gestational sac. The 26-week examination confirmed a monochorionic monoamniotic (MCMA) twin pregnancy with a single placenta. Fetus A was structurally normal on detailed ultrasound examination and appropriately grown, with a biparietal diameter of 5.32 cm, femur length of 4.77 cm, abdominal circumference of 21.46 cm, estimated fetal weight of 813 g, and cardiac activity of 152 beats/min. Fetus B had absent cardiac activity and fetal movement with a collapsed, crumpled contour, precluding reliable assessment of gestational age. The measured biparietal diameter, femur length, and abdominal circumference were 2.64 cm, 3.78 cm, and 9.75 cm, respectively, corresponding approximately to 20 weeks of gestation. The ultrasound impression was intrauterine fetal demise of Fetus B, with TTTS considered a possible underlying cause. No gross structural abnormality was identified in the surviving fetus.
Outcome: At approximately 33 weeks of gestation, the patient went into spontaneous labour and delivered vaginally, resulting in one macerated stillbirth and one live-born infant weighing 1200 g. Despite being born alive, the surviving neonate died on the seventh day of life. Approximately two months postpartum, the mother developed bilateral lower-limb oedema and mild generalized swelling; further evaluation was not documented.
Conclusion: This case highlights the diagnostic and management challenges associated with monochorionic twin pregnancies when early chorionicity assessment and structured antenatal surveillance are limited. The occurrence of sIUFD followed by neonatal death of the surviving co-twin underscores the potentially severe consequences of complications in monochorionic pregnancies. Standardized first-trimester determination of chorionicity, appropriate antenatal surveillance, and timely referral to specialized fetal medicine services are particularly important in resource-limited settings.

BJusg. vol. 27, no. 1, June 2026, Page: 70-78