Genetics and Reproduction: IVF and ICSI with PGD

Based on Reproductive genetics understanding, therapies are developed and used to maximize outcomes.

Specifically, increased pregnancy rates,decreased incidence of obstetric complications and miscarriage, and the avoidance of fetuses affected by birth defects or other deficiencies are the stated goal of much of the current research in reproductive medicine. The role of genetic testing to guide medical decision making in this regard is sizable and will likely continue to grow in the future.

Genetic evaluations within reproductive medicine may be subdivided into 4 main categories:

1. Preconception genetic testing: The genetic evaluation of prospective parents before pregnancy.

2. Antenatal genetic testing: The genetic evaluation of women who are currently pregnant to determine  the genetic makeup of the developing fetus.

3. Preimplantation genetic testing ( PGD and PGS): The genetic evaluation of an embryo, before uterine transfer, via an embryo biopsy during an in-vitro fertilization (IVF) procedure.

4. Genetic analysis following fetal demise: The genetic evaluation  of the product of conception following a failed pregnancy.

 

IVF and Endometriosis

Endometriosis is a common gynecological condition that affect approximately 10-15% of the female population.

Endometriostic ovarian cysts may be present in up to 20-40% of women with endometriosis scheduled for IVF and on both sides in 19-28% of the cases.

The best medical approach to treat endometriotic ovarian cysts is controversial, as it may delay the fertility, the lady desires.

Should we remove the endometriosis by surgery is matter of debate.

With surgery , there are great chances that it may affect the ovarian reserve and impairs the responsiveness to treatment, and also does not offer any additional benefit in terms of fertility outcomes.

In addition, surgery is great risk to women, as it is mostly a complicated surgery.

The laparoscopic removal of bilateral endometriomas prior to IVF should be limited to those cases with normal ovarian reserve, presence of pain symptoms, rapid growth or sonographic features of malignancy.

Conversely., in the absence of the above-mentioned features, patients with bilateral endometriomas should be encouraged to proceed directly to IVF to reduce time to pregnancy, to avoid potential surgical complications and to limit costs.

The retreival of oocytes may be less in endometriotic cases, compared to normal, but the quality of oocytes may be same and pregnancy rates may be comparable, if lady goes for IVF as early as possible, when all conservative approaches are exhausted

Blastocyst transfer may help in repeated IVF failure cases

Recurrent implantation failure may identified after three failed IVF cycles or after transfer of 10 high grade embryos. There are many different factors which may contribute for this recurrent IVF failure, such as parental chromosomal translocations, abnormal uterine anatomy , hydrosalpinx, or inadequate  culture conditions or embryo transfer techniques.

Failure may be due to factors with the “Seed,Soil or the Cultivator”

Some studies have suggested that local injury of the endometrium by means of a catheter or hysteroscopy can induce an inflammatory response that may facilitate the preparation for implantation.

Artificial rupture of the covering of the embryo ( Zona pellucida) may improve implantation: Assisted Hatching, but is still not proved.

Pre-implantation genetic screening of the embryos is now a day used to get and select best embryos. But this strategy did not show any improvement in patient outcome  and did not show any significant difference on clinical pregnancy rates.

A few studies have reported that congenital and acquired prothromotic conditions are more prevalent in women with recurrent implantation failure. Therefore use of low molecular weight heparin (LMWH) and mini dosage of aspirin on patients with thrombophilia and recurrent implantation failure has been discussed, but large studies are required to prove them .

Finally, another possible strategy is to extend embryo culture to blastocyst stage, aiming to improve embryo selection and uterine receptivity