Fetal brain hemodynamic changes in intrauterine transfusion: influence of needle puncture site.

OBJECTIVES: Previous research has suggested that hemodynamic changes after in utero transfusion may be related to fetal stress. We tested the hypothesis that these hemodynamic changes are more pronounced when the needle is inserted in the fetal abdomen compared with the umbilical cord root.

METHODS: Most intrauterine transfusions are performed by inserting a needle either in the umbilical cord root at the placental surface (PCI) or in the intrahepatic portion of the umbilical vein (IHV). We analyzed prospectively collected data of all intrauterine blood transfusions (IUT) for fetal alloimmune anemia (from 2000 to 2003), for which complete data were available on needling site and middle cerebral artery (MCA) Doppler flow velocity measurements before and immediately after the procedure.

RESULTS: Data of 57 IUTs were included. In 32 patients, the transfusion was performed through the PCI and in 25 patients through the IHV. Mean pulsatility index (PI) in the PCI group was 2.0 before and 1.7 after IUT (p = 0.011), and in the IHV group 1.9 before and 1.5 after IUT (p = 0.001). In both groups, MCA PI decreased significantly, but there was no difference in decrease between the two groups (p = 0.99).

CONCLUSIONS: In anemic fetuses undergoing transfusion, the observed fetal brain hemodynamic changes were independent of the site of needle insertion. The decrease in fetal MCA PI is therefore likely to be caused by the volume expansion.