ABSTRACT
OBJECTIVE: To study the extent of fetomaternal transfusion and the outcome of pregnancy after cordocentesis. MATERIAL AND METHODS: 268 women underwent percutaneous fetal umbilical cord blood sampling for fetal karyotyping between 15 and 26 gestations of weeks. Complete follow-up was available in 221 (82.5%) of the cases. Cordocentesis was performed under continuous real-time ultrasound guidance. The duration of the procedure and the post-procedural bleeding time was counted in seconds. Fetomaternal transfusion was calculated by using the measurements of the maternal serum levels of alpha-fetoprotein before and after the procedure. The data were analyzed by Student's t and multiple regression tests. RESULTS: The maximum and mean amounts of fetomaternal transfusion were 1.067 and 0.061 ml, respectively. Twenty percent or more alpha-fetoprotein elevation was in 35.4% of the cases. Positive correlation was found between bleeding time after cordocentesis and fetomaternal transfusion (r = 0.174, p < 0.0129) as well as between the duration of the procedure (r = 0.165, p < 0.0171) and the amount of fetomaternal transfusion. Comparing the cordocentesis at the placental insertion site and at the free cord loop, a smaller amount of fetomaternal transfusion was observed (p < 0.0123) in the latter. Transplacental passage was associated with a higher amount of fetomaternal transfusion (p < 0.0067). No association was found between the extent of fetomaternal transfusion and the outcome of pregnancy. The fetal loss related to the cordocentesis was 0.50%. CONCLUSIONS: The extent of fetomaternal transfusion was influenced by the subsequent four parameters: procedural time, bleeding time, puncture site and transplacental penetration. The lack of the association between the degree of fetomaternal transfusion and the outcome of pregnancy, along with the low (0.50%) post-procedural fetal loss rate, suggest that cordocentesis is clinically a safe procedure.
