Women who have undergone an intrauterine transfusion due to hemolytic disease of the fetus and newborn (HDFN) have an increased risk of requiring an intrauterine transfusion in subsequent pregnancies, according to a recently published study in The International Journal of Obstetrics and Gynecology.
An intrauterine transfusion is an invasive procedure in which red blood cells are injected into the fetus. The procedure requires the administration of antibiotics and sedation and is associated with risks such as premature labor, fetal distress, infection and bleeding.
HDFN is thought to worsen with each pregnancy. After undergoing intrauterine transfusions due to HDFN, patients are commonly warned that in a subsequent pregnancy, they could require another intrauterine transfusion earlier in the pregnancy.
Read more about HDFN causes and risk factors
Although the increased risk of requiring an intrauterine blood transfusion earlier in pregnancy is treated as common knowledge, few studies have been published that quantify how severe the risk actually is. More data on this subject could help physicians make therapeutic decisions and aid them in assessing whether a patient should be treated for HDFN.
“We found no adequately sized studies quantifying the risk of severe HDFN in pregnancies following a pregnancy in which treatment with [intrauterine transfusions] to the fetus was necessary,” the authors wrote.
The authors aimed to quantify the risk of requiring intrauterine transfusion in subsequent pregnancies using an electronic patient database, including information from all patients who received intrauterine blood transfusion between 1999 and 2017.
The search yielded 321 cases of pregnancies requiring intrauterine blood transfusions during the required time, of which 69 had a subsequent pregnancy. Of those, more than 86% required an intrauterine transfusion. On average, the transfusion was administered three weeks earlier than in each patient’s previous pregnancy.
The authors observed that when intrauterine transfusion was not needed in the second pregnancy, the baby was more likely to be delivered preterm and have anemia at birth, suggesting that an intrauterine transfusion could have been required if the pregnancy had lasted longer.
In light of the findings, the authors recommended that pregnant patients with a history of a previous intrauterine transfusion due to HDFN could benefit from receiving advanced treatment.
“Our study provides additional evidence to support who should be considered for IVIg or new immunomodulatory agents, such as FcRn-targeted inhibitors,” the authors wrote.
