Hypercoiled cord can cause a reversible abnormal Doppler in ductus venosus in cases of fetal growth restriction

Aim: Although an absent or reversed a-wave in ductus venosus (DV-RAV) is reported to be the terminal finding of fetal growth restriction (FGR), we have seen DV-RAV that disappears within a short span of time in some FGR cases with a hypercoiled cord. The purpose of this study was to investigate the relationship between hypercoiled cord and reversible DV-RAV in FGR.

Methods: This was a retrospective study of 499 FGR cases, including 14 with DV-RAV. Transabdominal amnioinfusion (AI) was performed when oligohydramnios was severe (maximum vertical pocket <2 cm) and/or variable deceleration was detected. DV-RAV that disappeared quickly was defined as 'temporary DV-RAV'. DV-RAV that continued until delivery or fetal death (FD) was defined as 'persistent DV-RAV'. A hypercoiled cord was defined as one with an umbilical coiling index >0.6 antenatally or >0.3 postnatally. Clinical characteristics and clinical courses of the two types of DV-RAV were compared.

Results: DV-RAV disappeared after AI in all five cases in which temporary DV-RAV was identified. The incidence of a hypercoiled cord was significantly higher among temporary DV-RAV cases (100%) than among persistent DV-RAV cases (14.3%; P = 0.015). The time from detection of DV-RAV to delivery or FD was significantly longer among temporary DV-RAV cases (4.5 weeks) than among persistent DV-RAV cases (0.7 weeks; P = 0.027).

Conclusion: Temporary DV-RAV is suspected to be related to the combination of a hypercoiled cord and oligohydramnios. DV-RAV may not be always be a terminal finding in FGR with a hypercoiled cord.