The endometrium must be in perfect condition and with an adequate thickness to favor embryo implantation at the time of the embryo transfer. For this reason, the doctor will most likely prescribe estrogens and progesterone to the patient. These hormonal drugs will cause the endometrium to grow until it reaches a thickness of 7-10 mm and a trilaminar aspect, that is, the ideal characteristics for pregnancy to occur.
About 12 days after the embryo transfer, the patient will undergo a pregnancy test. If the result is positive, doctors usually recommend continuing with progesterone until approximately 10-12 weeks of gestation.