The underlying causes of infertility are multiple and the current advanced technique followed in IVF (In-vitro fertilization) can successfully treat almost all causes of infertile conditions. However, the success rate of IVF is reasonable in most of the cases, which is approximately 30% with the live birth rate. This scope of success will cumulative with repeated IVF cycle.
The steps followed in the IVF process include oocytes retrieval (egg removal) from ovaries, oocyte fertilization with collected sperm in an embryology laboratory, and subsequent embryo transfer by selecting and placing the best quality embryos into the intended mother's womb for further growth of the embryo. All of these steps are standard and controlled.
But unfortunately, the IVF pregnancy rate is not 100% after the first or second attempt even after the commencement of all the steps in the IVF process with full dedication. Intended parents often become devastated after getting a negative pregnancy test in IVF. Although reproductive technology is improving continuously and try to search the underlying cause of the condition.
The common cause of failure of IVF treatment is the cessation of the growth of the embryo before implantation. Other possible reasons for IVF failure include negative uterine receptivity and the mechanism of embryo transfer does not match with uterine acceptability. However, in most cases, poor quality of the embryo is considered a common cause of the failure of the IVF cycle.
The common parameters for the selection of good quality embryos are referred to as the continuation of embryo growth after transferring them into the uterus and the ability to “stick” within the uterine line.
The embryologists have predicted the quality of embryo by considering certain features before selecting them for implantation. All formed embryos after fertilization is allocated grades depending upon their growth rate and certain other traits like cellular symmetry, fragmentation degree, etc.
Usually depending upon the assigned gradation, the high-quality grade of embryos is selected for implantation. But sometimes, perfectly looked embryos do not select for implantation.
The clinical experience of an embryologist is also a considerable factor as the selection is based on the prediction. The expert embryologist also considered the quality of egg of the women collected for fertilization from which embryo is produced.
Sperm quality also an important component in case of good quality embryo production along with infrastructure and availability of facilities of the embryology laboratory. However, the quality of the egg is a much more important factor than sperm quality, as the egg is responsible for a normal chromosomal component of the growing embryo.
Maternal age is a considerable factor for the quality of egg; however, that can not only vary with years but monthly variations are also significant. A different batch of eggs produced in women's ovary in every menstrual cycle, which are used for the IVF cycle.
The treatment plan referred by the IVF doctor has also significant effect, as the quality of selected egg for fertilization depends upon the preference of ovarian stimulation protocol, selection of hormonal therapy to achieve follicle development, and the ovulation trigger moment.
The IVF experts advice to try another cycle of IVF in case of first or second attempt failed, as the egg quality varies with cycle-to-cycle. Besides this, the idea of suitable ovarian stimulation protocol may achieve from the previous IVF attempt experience.
The scope of getting pregnant through the IVF process remains the same for the initial 3 to 4 attempts, then the scope gradually decreases. Although recent research results reported that the probability of obtaining pregnancy was outstanding even after six attempts, though the maternal age is an important factor. According to this research result, almost 86% of women within 35 years of age had achieved their pregnancy, whereas 40% of pregnancy was achievable over 40 years of women's age.