The most important factor that determines IVF success is female age. After the age of 35 egg quality begins to decline. Unfortunately, this decline continues with advancing age and picks up pace after 38. After 43 years this decline in egg quality can reach up to 80-90%. Not only egg quality declines, but egg count also tends to decrease biologically with age.
Embryos carry the genetics of both eggs and sperm. Therefore, sperm quality is one of the important factors. DNA material found in the head of the sperm activates from the third day of embryo development. It is important to closely trace embryo development to day 5 or 6 days while it reaches the blastocyst stage to better understand how both sperm and egg quality affect embryo development.
The success rate in subsequent treatments continues to decline for the couples that had 3 or more IVF failures despite the transfer of good-quality embryos.
The internal membrane of the womb is called the endometrium. This membrane is vital for the baby to implant and grow. The embryo may not implant properly if the thickness of this membrane is less than 7 mm on the day of planned embryo transfer, or if there are polyps, myomas, or adhesions present.
A woman has two fallopian tubes, one on the left and one on the right side of the uterus. It is the organ in which an egg meets sperms during the natural pregnancy process, the embryo grows and develops here in one of the tubes before moving further into the womb. In some cases fluid builds up in one or in both tubes, this is called hydrosalpinx. This pathological fluid then flows into the womb, preventing the embryo from implantation or development.
Apart from these medical factors, maintaining a healthy life, weight control, paying attention to nutrition, and abstaining from smoking and alcohol are also crucial.