Infants are generally cleared of HDFN when weekly draws reveal that the hemoglobin or hematocrit is rising for 2-3 weeks in a row. At this point the infant no longer has issues with hyperbilirubinemia, and further blood draws for anemia are no longer necessary. Neutropenia and thrombocytopenia may persist beyond 12 weeks. In this case, they are simply managed as usual, there is nothing extra needed. The infant can be cleared of HDFN.
Long-term outcomes for infants with HDFN
Long-term outcomes for infants with HDFN are favorable. The largest predictor of reduced neurological outcomes was the appearance of fetal hydrops 88. The LOTUS study (the largest cohort study of children who received IUTs) followed 291 children ages 2-17 years old and found that “the overall incidence of neurodevelopmental impairment was 4.8% (14/291)90”. Previous studies show similar or improved neurological outcomes for infants treated with IUTs. In 1993 Doyle et al reported 35 of 38 infants (92%) treated with IUTs had no sensorineural disability at 2 years of age 91. In 1998 Hudon looked at 40 infants with HDFN due to anti-D who were treated with IUTs. All 40 showed normal neurodevelopmental outcomes at >5 years of age 94. In 1999 Grab et. al., also showed no moderate or severe neurological impairment in 35 infants who had received IUTs 93. This data stands in stark contrast to the findings from Harper et. al. where 22% (4/18) hydropic fetuses treated with IUT had major neurological morbidities or death, and 12% of the surviving infants had major neurologic sequelae 92. Severe hydrops may be associated with a higher risk of impairment 71, 72. For infants who did not develop hydrops and who were not treated with IUTs, normal outcomes should be expected.
