Sellier P, et al. – This retrospective study aimed to evaluate the Hepatitis B Virus (HBV)/Hepatitis D Virus (HDV) mother–to–child (MTC) co–transmission. The physicians proposed that HBV/HDV MTC co–transmission was exceptional. Studies were required, chiefly in developing countries.

• The physicians performed this monocentric retrospective study, after informed consent in HBV/HDV co-infected women pregnant between 01/01/2004 and 01/01/2015 in Paris, France.
• They tested the children when they were 24 months of age or older.

• During the study period, 22 (3%) out of 742 HBV infected women, HDV co-infected, gave birth to 54 children.
• With HDV RNA of less than 2.3 Log₁₀ I.U/mL, HBV DNA was above 5 Log₁₀ I.U/mL in 10 pregnancies previous any treatment.
• With HBV DNA of less than 1.5 Log₁₀ I.U/mL, HDV RNA was above 5 Log₁₀ I.U/mL in 8 pregnancies previous any treatment.
• The physicians observed inverse patterns of HBV DNA and HDV RNA in 17 of 35 (49%) pregnancies: 13 (76%) received no HBV treatment; four (24%) were treated.
• At birth, HBV DNA was under 5 Log₁₀ I.U/mL in 46 of the 50 assessed women (92%).
• Among the 36 assessed children, given passive-active immunization, 24 (66%) were protected, 10 (28%) were neither infected nor protected, 1 was chronically HBV infected, and 1 had a past HBV infection.
• In the 36 children, HDV Ab was negative.