Abstract
Objective
To assess the predictive value of middle cerebral artery Doppler peak systolic velocity (MCA-PSV) for moderate-severe fetal anemia following one intrauterine transfusion (IUT) and test the performance of alternate cutoffs to the recommended threshold ≥1.69 multiples of the median (MoM).
Methods
This was a retrospective cohort study of patients with pregnancies affected by alloimmunization who underwent percutaneous umbilical blood sampling (PUBS) procedures from 2000 to 2020. An MCA-PSV ≥1.69 MoM was the indication for the second IUT. The primary outcome was recurrent moderate-severe fetal anemia. Receiver-operating characteristic (ROC) curves assessed the predictive ability of MCA-PSV for the primary outcome and the Youden index identified the “optimal” cutoff value. Predictive characteristics of MCA-PSV ≥1.69 MoM and the “optimal” cutoff were compared.
Results
Of the 58 patients who underwent IUT during the study period, 36 (62%) did not meet inclusion criteria. Of the remaining 22 patients who underwent a second PUBS, 12 (54.6%) fetuses had moderate or severe anemia. Following one IUT, the AUC for MCA-PSV was 0.86 (95% CI 0.70–1.00) for the primary outcome. The “optimal” cutoff MCA-PSV value was 1.74 MoM, which had a greater specificity than ≥1.69 MoM (90 vs. 50%, p = .05), but was not statistically significant. The sensitivity was similar between the two cutoff values of ≥1.69 and ≥1.74 MoM (83.3 vs. 75.0%, p = .65) (Table 2).
Conclusion
Raising the recommended MCA-PSV cutoff to ≥1.74 MoM for recurrent moderate-severe fetal anemia after one IUT would decrease the number of unnecessary procedures without significantly changing the sensitivity of this screening test.
Disclosure statement
The authors have no conflicts of interest to declare.