Initial investigations for NIHF include an indirect Coombs test to exclude immune causes, followed by the determination of routine blood counts and indices to exclude thalassemias; maternal blood chemistry testing for G6PD deficiency; Betke-Kleihauer testing for fetal-maternal transfusion; and screening for toxoplasmosis, other infections, rubella, CMV, and herpes simplex (TORCH) infection during intrauterine pregnancy.