The basic tests start with the evaluation of egg quality and growth. The human egg is too small to be seen by ultrasound. The follicle housing and nourishing the egg can be seen by ultrasound. Therefore tracking the follicle with ultrasound is the simplest and cost-effective way to assess the egg.
Transvaginal ultrasound (TVS)evaluation of the ovary, ( painless ) will detail follicle growth in response to drugs and will guide the time for fertilization. This will also identify specific problems of ovulation. This is also known as FOLLICULAR TRACKING or monitoring. It has to be done serially in the cycle usually starting on cycle day 13. The study has to be done during every month of treatment as the pattern may differ according to treatment. This gives a complete picture of the follicular growth which in turn reflects that of the egg. However, there can be disparities. The egg is not visible on ultrasound. However, the growth of the follicle parallels the maturity of the egg. The mature follicle measures 17 mm across.
The inner lining of the uterus, the endometrium grows in response to the estradiol hormone secreted by the follicle lining cells. Hence a three-layer appearance like leaf ensures a good follicular function.