In vitro fertilization is not allowed for coital sperm retrieval. This is because if you have intercourse for sperm retrieval before egg retrieval, it can easily lead to ovarian tibial torsion, and in severe cases, the ovaries may have to be removed. Intercourse before egg retrieval may also lead to early ovulation in those with few follicles, resulting in a situation where no eggs are retrieved. If you have intercourse for sperm retrieval after egg retrieval, it may cause infection and bleeding from the vaginal puncture site, etc. Therefore, you should not have intercourse for sperm retrieval on the day of egg retrieval. If the male partner has difficulty retrieving sperm, he can take oral medication such as Viagra or have a surgical puncture to retrieve sperm. If the sperm cannot be retrieved even by surgical puncture, the eggs can be frozen. Alternatively, the sperm can be frozen in advance as a backup because after freezing the sperm, the male partner will have very little psychological stress and the sperm retrieval may go smoothly. If it is difficult to retrieve sperm on the day of egg retrieval, the frozen sperm can be revived and used for fertilization.