Once fertility treatment has been initiated, transvaginal sonographic monitoring of both the endometrium and follicular development starts.
Your endometrium is evaluated for both the thickness and morphologic pattern.
Endometrium evolves from a thin less than 4 mm echogenic linear appearance early in the menstrual cycle to a trilaminar or multilayered striated appearance measuring up to 12-14 mm in the periovulatory stage.
Endometrial thickness increases on each subsequent sonogram st during the 1 half of the cycle. Clinical pregnancy rates are reported to be highest when the endometrium measures more than 9-10mm in thickness at the time of embryo transfer. Endometrium of <6mm correlates with decreased likelihood of full term pregnancy.
Patients undergoing transfer of embryos frozen during a prior stimulated cycle, only require targeted endometrial evaluation with attention to morphologic appearance and thickness to determine optimal timing of the transfer.
It is preferred to transfer embryos when the endometrium demonstrates a trilaminar appearance and is 7mm or more in diameter.