Foetal heart rate pattern after complete cord occlusion by radiofrequency ablation for selective reduction in the complicated monochorionic twin pregnancies

Background: The purpose of the present study was to assess foetal heart rate (FHR) pattern after complete cord occlusion by radiofrequency ablation (RFA) for selective reduction in the complicated monochorionic twin pregnancies. Materials and Methods: A prospective cohort study was done at an Iranian Hospital in 2016–2017 on 85 pregnant women candidate for selective reduction by RFA. Umbilical vein was cauterised two times (power 100 Watt) for 2 min. Cease of blood flow was confirmed by colour Doppler and FHR was recorded. Then, the pattern of FHR after cord blood occlusion was assessed and recorded with certain intervals until cardiac asystole. Results: Of all 85 participants who entered the study, 59 cases with normal heart echocardiography were eligible. After about 4-min post-RFA, FHR steeply dropped to <80 beats/min. In 10 min, FHR deceased to about 60 beats/min, and in 20 min, it reached to 40 beats/min. At the 15th min after RFA, the majority of foetuses and at 85th min, all the foetuses showed cardiac asystole. Conclusion: We found that about 4 min after complete cord occlusion by RFA, FHR steeply decreased to problematic ranges. Our results indicated that in similar conditions such as foetal hypoxia and time for rescuing of foetus was too limited. Moreover, it is supposed that such a pattern of heart rate in preterm foetuses may be presented in terms, so tight monitoring of FHR trend, presence of an expert surgery team and advanced hospital facilities seems necessary.