As we all know IVF has its limitations and a variety of factors influence the outcome. Some of them are under our control and some of them are not.
Outcome of an IVF cycle depends on the quality of the embryo which in turn depends on the egg quality and the sperm quality. Egg quality is mainly dependent on the age of the woman. As the age increases , particularly in the late thirties , the chances of having aneuploid/ abnormal eggs increases. ICSI( intracytoplasmic sperm injection) can overcome most of the sperm related problems but severely abnormal semen samples can give rise to poor quality embryos, thereby compromising the IVF success rates. Egg numbers are equally important. Studies show that the IVF success increases as the number of eggs retrieved increases upto about 15 eggs. Thereafter there is no further increase in the success.
About 10-15% of IVF failures could be because of implantation failure as well. Mechanical factors like fibroids especially the submucous variety ( one which grows into the uterine cavity) and large intramural fibroids, adhesions inside the uterine cavity, adenomyosis, abnormally swollen tubes (hydrosalphinx), endometrial polyps, uterine anomalies like septate uterus. Very few of them can have immunological dysregulation of the NK cells which causes rejection of the embryo.
Optimal selection of IVF stimulation protocol is very important. As already mentioned egg numbers are important. Depending on the ovarian reserve tests patients can be categorised into Hyperresponders, normoresponders or poor responders.Giving the right dose of gonadotrophins helps in retrieving a good number of eggs(# 8-15) without subjecting the patient to the undue risk of ovarian hyperstimulation syndrome. Most of them fit into short protocols which takes about 10-12 days and long protocols are reserved for conditions like endometriosis or adenomyosis.
The most critical element in the IVF success is the culture conditions provided in the ivf laboratory. A clean room with optimal VOC (volatile organic compounds) and particulate count is an absolute requirement. Strict quality control measures should be in place. Good incubators and culture conditions along with the experience of the embryologist makes a huge difference in the success of an IVF program. Freezing and survival rates of the embryos after thawing should be good for the centre if you are considering a frozen embryo transfer. The implantation of the embryo is compromised in a fresh IVF cycle because of the excessive estrogen hormone from the multiple eggs. This effect can be overcome by freezing all embryos in a fresh cycle and transferring them in a frozen cycle. Frozen embryo transfers are more physiological and implantation is very good. But a good freezing and vitrification program is a must to carry out an ‘all freeze’ cycle.
Technique of embryo transfer is again an important aspect. 30% of all IVF failures could be due to faulty transfers. It should be very gentle and meticulous. Where ever there is difficulty, its a must to do a hysteroscopy or a mock transfer or cervical dilatation before starting the cycle.
Adequate luteal phase support with progesterone and estrogen is equally important after embryo transfer.
So choosing the best IVF centre with a good clinical and embryological expertise and a clean room IVF lab with strict quality control measures goes a long way in determining the success of an IVF program.