According to Buddhism, what is the cause and effect of pregnancy without fetal heart?

Scientifically speaking, there is no embryo and fetal heart in the gestational sac, but there is something wrong with the quality of the embryo. There are many reasons for abortion, such as embryonic hypoplasia, abnormal pregnancy eggs, etc. Placental dysplasia, maternal-fetal blood group incompatibility; Female endocrine dysfunction and reproductive organ diseases; Female pregnancy trauma, emotional mutation; Taking medicine or viral infection during pregnancy; Male sperm quality problems; Both men and women have chromosomal abnormalities.