Monitoring IVF treatment cycle
There are several aims when monitoring the treatment cycle. These include: checking the development of follicles and lining of the uterus, to adjust the dose of the drugs if necessary and to time the hCG injection. Each patient is different, so the ovarian response varies between patients both in the number of follicles produced and the speed at which they mature. On average, you need to attend the clinic for two or three visits and occasionally more to see how well you have responded to the injection and adjust the dose of the injections accordingly.
The development of the follicles (fluid-filled sacs containing the eggs) is routinely monitored using serial ultrasound scans (preferably vaginal scan as it gives a better image than abdominal scan). In the majority of treatment cycles the patient will have approximately 4 scans. The number of follicles is counted and the diameters of the growing follicles are measured. The ultrasound is also used to measure the thickness of the endometrium and assess its quality for implantation of the embryo. Serial blood samples may also be taken to measure the levels of estrogen and sometimes LH and progesterone. Estrogen production increases as the follicles develop.
After about 10-12 days of the gonadotropin injections, the follicles will almost be mature. When the ultrasound scan indicates a reasonable size and number of follicles and the diameter of the leading follicles is greater than 18 mm. In addition, the lining of the womb is of good thickness and quality. The estrogen levels correspond to the number of growing follicle. You will be asked to stop both the GnRh agonist and the FSH/hMG injections and a different type of injection called human chorionic gonadotropin (hCG) is given in a dose of 5000-10000 iu (recombinant hCG is as effective as urinary hCG). The injection is essential because it simulates the woman’s natural LH surge. This surge also initiates the final growth spurt of the eggs. hCG injection is carefully timed and is usually given at night to allow egg collection to be performed at a convenient time, about 36 hours later. The number of follicles is no guarantee of the number of the eggs that will be collected.
HCG is given in a dose of 5000-10000 iu. There are two different types of HCG (recombinant hCG and urinary hCG). Recombinant hCG is as effective as urinary hCG but more expensive. HCG is essential because it simulates the woman’s natural LH surge. This surge also initiates the final growth spurt of the eggs. hCG injection is carefully timed and is usually given at night to allow egg collection to be performed at a convenient time, about 36 hours later. The number of follicles is no guarantee of the number of the eggs that will be collected.
How poor responder patient defined is based on number of mature follicles or eggs collected?
The majority of IVF centers defined poor responders patients as those with less then 4 follicles at the time of egg collection. However, there is a much variation between the centers (3 to 5 follicles). According to a recent ESHRE (the Bologna conference, 2011), it was determined that women whose egg yield was less than 3 qualified as 'poor responders'.