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Fetus

Poster Session 1

(367) Intrauterine transfusion before and after 34 weeks: procedure-related complications and gestational age at delivery

Tuesday, February 13, 2024
10:30 AM – 12:00 PM  
Location: Prince George's Exhibit Hall CDE, Lower Atrium Level
Objective: Maternal red blood cell alloimmunization may be treated with serial intrauterine transfusions (IUT). Few studies are available regarding the safety profile of IUT performed after 34 gestational weeks as a strategy to postpone delivery until term. In patients undergoing their final IUT before and after 34 weeks, the following were assessed: (1) the frequency and type of procedure-related (PR) complications; (2) gestational age (GA) at delivery.

Study Design: This was a retrospective study of pregnancies complicated by alloimmunization with suspected fetal anemia treated with IUT at a single center. PR-complications were defined as any of the following within 48 hours of IUT: 1) rupture of membranes or preterm delivery, 2) intrauterine infection, 3) fetal death, 4) fetal compromise resulting in emergency cesarean, or 5) neonatal death. The secondary outcome was GA at delivery. Study outcomes were compared between patients with final IUT before and after 34 gestational weeks.

Results:

In total, 94 pregnancies with 237 IUT met inclusion criteria. Among the 94 pregnancies, 59 (62.8%) had their last IUT before and 35 (37.2%) had their last IUT after 34 gestational weeks. Maternal age, parity, GA at first IUT, and the presence of hydrops were similar between the groups. Patients with the last IUT after 34 weeks underwent more IUT per pregnancy (mean 3.2 versus 2.1, p < 0.01). There were 3 PR-complications identified (1.3% of procedures and 3.2% of pregnancies); 2 were in the group with their last IUT after completing 34 weeks. There was no difference in PR-complications when comparing pregnancies with their last IUT before and after 34 weeks (p = 0.28). Pregnancies with the last IUT after 34 weeks delivered at a later GA (mean 37.1 versus 36.0 weeks, p < 0.01).

Conclusion:

IUT PR-complications were rare. IUT beyond 34 gestational weeks did not appear to pose additional risk to the pregnancy and may mitigate the risk of premature delivery. Future studies are needed to validate these findings and examine cost effectiveness and patient tolerability of additional IUT.