Fetomaternal transfusion and pregnancy outcome after cordocentesis

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 bet ween 15 and 26 gestations of weeks, Complete follow-up was available in 221 (82.5%) of the cases. Cordocentesis was performed under continuous real-ti me ultrasound guidance. The duration of the procedure and the post-procedur al bleeding time was counted in seconds. Fetomaternal transfusion was calcu lated by using the measurements of the maternal serum levels of alpha -feto protein 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 perc ent or more alpha -fetoprotein elevation was in 35.4% of the cases. Positiv e correlation was found between bleeding time after cordocentesis and fetom aternal 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 tr ansfusion. Comparing the cordocentesis at the placental insertion site and at the free cord loop, a smaller amount of fetomaternal transfusion was obs erved (p < 0.0123) in the latter. Transplacental passage was associated wit h 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%. Conclusi ons: The extent of fetomaternal transfusion was influenced by the subsequen t four parameters: procedural time, bleeding time, puncture site and transp lacental penetration. The lack of the association between the degree of fet omaternal transfusion and the outcome of pregnancy, along with the low (0.5 0%) post-procedural fetal loss rate, suggest that cordocentesis is clinical ly a safe procedure. Copyright (C) 2001 S. Karger AG, Basel.