Risk factors for fetomaternal bleeding after laser therapy for twin-twin transfusion syndrome
To quantify and assess potential risk factors for transplacental passage of fetal red blood cells (RBCs) into the maternal circulation (fetomaternal bleeding, FMB) after laser surgery for twin-twin transfusion syndrome (TTTS).Study Design
A retrospective study of Rhesus-D negative patients that underwent laser surgery for TTTS. Patients with and without postoperative detectable fetal RBCs on Kleihauer-Betke (KB) testing were compared to determine risk factors for FMB. Patients were further sub-classified into those with a FMB < 20% and ≥20% of estimated fetoplacental blood volume.Results
Of 60 studied patients, 26/60 (43%) had a positive postoperative KB test. The median fetal:adult RBC ratio was 0.00125, estimated to be a FMB volume of 6.25 mL. There were 17/26 (65%) of patients with FMB < 20% and 9/26 (35%) patients with ≥20% of the fetoplacental blood volume. Stage III-Recipient and III-Recipient/Donor patients were more likely to have a positive KB test (14/21 [66.7%] vs 12/39 [30.8%], OR = 4.50 [1.27–16.54], P = 0.0162). No other risk factors for FMB were apparent.Conclusions
Fetomaternal bleed appears to be a common finding after laser surgery for TTTS. TTTS Stage, particularly stage III-Recipient and III-Recipient/Donor, appears to be a risk factor for FMB.