Background
Nationwide antenatal human T‐cell leukemia/lymphoma virus type‐1 (HTLV‐1) antibody screening has been conducted in Japan. The purpose of our study was to clarify the issues related to feeding options to prevent postnatal mother‐to‐child transmission.
Methods
Of the pregnant carriers at 92 facilities in Japan between 2012 and 2015, 735 were followed prospectively. Among the children born to them, 313 (42.6%) children were followed up to the age of 3 and tested for HTLV‐1 antibodies. The mother‐to‐child transmission rate was calculated for each feeding option selected before birth.
Results
Among the 313 pregnant carriers, 55.0, 35.1, 6.1, and 3.8% selected short‐term breast‐feeding (≤3 months), exclusive formula feeding, frozen‐thawed breast‐milk feeding, and longer‐term breast‐feeding, respectively. Despite short‐term breast‐feeding, 8–18% of the mothers continued breast‐feeding for 4–6 months. The mother‐to‐child transmission rate with short‐term breast‐feeding was 2.3% (4/172), and its risk ratio compared with that of exclusive formula feeding was not significantly different (0.365; 95% CI: 0.116–1.145). Because of the small number of children who were fed by frozen‐thawed breast‐milk, their mother‐to‐child transmission rate was not statistically reliable.
Conclusions
Pregnant HTLV‐1 carriers tended to select short‐term breast‐feeding in Japan. While short‐term breast‐feeding was not always easy to wean within 3 months, it may be a viable option for preventing postnatal mother‐to‐child transmission because the vertical transmission rate with short‐term breast‐feeding was not significantly higher than that with exclusive formula feeding. Increasing the follow‐up rates for children born to pregnant carriers may provide clearer evidence of preventative effects by short‐term breast‐feeding and frozen‐thawed breast‐milk feeding.