Ethical considerations of maternal-fetal intervention in a twin pregnancy discordant for anomalies

Recent evidence suggests prenatal fetoscopic tracheal occlusion (FETO) may improve the survival and long-term morbidity of neonates with congenital diaphragmatic hernia, yet little guidance exists in the medical literature as to the ethical permissibility of performing a maternal-fetal surgical intervention in a twin pregnancy discordant for a structural abnormality.

Here, we present a case of a twin pregnancy with an unaffected twin (Twin A) and a twin diagnosed with severe congenital diaphragmatic hernia (Twin B). A proposed fetoscopic tracheal occlusion (FETO) procedure may improve the likelihood of survival and postnatal outcome of Twin B; however, balloon placement may also initiate very preterm birth at 28 weeks of gestation. The Fetal Ethics Advisory Board was asked to provide guidance on the permissibility of FETO in this pregnancy.

A literature review identified one brief mention of FETO in a 34-week dichorionic twin pregnancy in the medical literature, which resulted in the rupture of fetal membranes in the sac of the nonsurgical twin. Only one paper specifically addressed the question of whether it would be ethically permissible to subject a healthy twin to the risks of maternal-fetal surgery for the benefit of a compromised twin, finding that any risk to the unaffected twin would be an ethical contraindication. We offer our own analysis of moral weight and risk/benefit considerations of this proposed intervention, and present our findings on the circumstances in which it may be ethically permissible to perform a maternal-fetal intervention in a twin pregnancy.

While FETO was not ethically advisable in this pregnancy, we find that in limited circumstances, certain maternal-fetal surgical interventions may be ethically permissible in a twin pregnancy discordant for a structural abnormality if the risks to the unaffected twin are minimal and the procedure would improve the likelihood of survival and postnatal outcome of a critically compromised co-twin.