Purpose or Case Report: Monochorionic multiple gestations are at risk for complications related to a shared placenta. In utero therapies such as fetoscopic laser and radiofrequency ablation (RFA) are used to treat these complications. Previous work at our institution demonstrated a low rate of neuroanatomical abnormalities on post-therapy fetal imaging. The purpose of this study was to evaluate postnatal neurological outcomes within the same cohort.

Methods & Materials: This was an IRB-approved retrospective study of postnatal neurological outcomes among fetuses exposed to either laser or RFA for complicated monochorionic multiple gestations. Inclusion required post-intervention fetal imaging. A review of postnatal clinical neurological examination and neuroimaging findings on head ultrasound (US) and brain magnetic resonance imaging (MRI) was performed.

Results: From our original cohort, 34 fetuses of the laser therapy group and 15 fetuses of the RFA therapy group had postnatal follow-up. In the laser group, the mean gestational age (GA) was 34 wks, with the majority (33/34) born premature. 13 neonates had a normal clinical neurological exam without further imaging. Head US (n = 21) or MRI (n = 2) was obtained in 21 neonates. Abnormal findings on US were seen in 7 neonates, including echogenic periventricular white matter (n = 1), germinal matrix hemorrhage (GMH) (n = 3) and prominent ventricles (n = 3). Two abnormal US cases went on to have MRI, which showed cystic encephalomalacia in one and periventricular infarcts and leukomalacia in the other. In the RFA group, the mean GA was 35 wks. 6 of 15 patients were premature (mean GA 30 wks). 10 neonates had a normal clinical neurological exam without further imaging. Head US (n = 5) or MRI (n = 1) was obtained in 5 neonates. Head US was normal in 4 cases, including one with a previously seen GMH on fetal MRI. One abnormal head US showed echogenic periventricular white matter with a follow-up MRI showing a small hemorrhage/ calcification in the periatrial white matter.

Conclusions: The postnatal neuroimaging abnormalities in neonates of complicated monochorionic gestation treated by in utero therapy are 20% in the laser group and 7 % in the RFA group. Given the high rate of prematurity in these groups, it is unclear if outcomes are due to in utero therapy or prematurity. There is little prior work examining postnatal imaging findings of this patient population, therefore these results can aid in prenatal counseling and guide postnatal care.