Hormones and medications are administered to stimulate egg development in the ovaries, depending on the needs of the individual. Ovarian response to the stimulating hormones is assessed by measuring levels of hormones in the blood and monitoring the number and size of the follicles in the ovaries, Endometrium thickness by ultrasound scan.
The first scan will be“carried out on day 2 or 3 of menstrual period, and the second scan is usually done 6-7 days after starting the injections, and serial scan will be monitored until the leading follicle is at certain size and the hormones are at the appropriate level, you will have a single trigger injection of human chorionic gonadotropin HCG to trigger ovulation. Egg collection will be scheduled within 34-36 hours after HCG administration.
The timing of this injection is crucial. The eggs will not be mature and are unlikely to fertilize if they are collected too soon. On the other hand if the collection takes place too long after the HCG injection, you may have already ovulated and released the eggs before collection. Treatment cycle may be cancelled from a poor ovarian response to stimulation or ovarian hyper stimulation syndrome (OHSS)