The Suwa Maternity Clinic in Nagano Prefecture has carried out IVF for 110 couples using sperm from fathers of husbands, with 95 of the women becoming pregnant and 79 giving birth, reported the Kyodo news agency.
Among them, 17 gave birth twice, while others gave birth for a third or fourth time, the report said.
146 couples received sperm from close relatives at the hospital due to the husbands' infertility, said Yahiro Netsu, the clinic's director.
Netsu is expected to announce the outcome of the fertilisation at a meeting of the Japan Society of Fertilisation and Implantation in Tokyo on Thursday.
For more than sixty years, artificial insemination using sperms from anonymous donor has been conducted in Japan but such a fertility treatment using sperm provided by relatives remains controversial due to its potential to complicate family relationships, the report said.