Does Preimplantation Genetic Diagnosis for Sex Selection Affect the Pregnancy and Miscarriage Rates in Women With an Expected Good Ovarian Response Undergoing IVF/ICSI Cycles?

Records of women who had PGD over the last 3 years will be reviewed and its outcome will be compared to other records of women who had IVF/ICSI without PGD Before starting the PGD process couples were seen by a geneticist to assess the feasibility of the procedure for each couple. Couples were then counselled by a gynaecologist specialised in IVF to assess their fertility status and explain the whole procedure including the expected success rates and risks of IVF.

Women had standard pituitary down-regulation with GnRHa (Triptorelin 0.1mg, Decapeptyl® Ferring, Germany) day 7 after ovulation of previous cycle or on day 21 of the oral contraceptive cycles. GnRHa was continued for 2 weeks. Human menopausal gonadotrophin(HMG) (Merional ®IBSA) 150-300 IU/day was administered until the day of HCG administration, Transvaginal oocyte retrieval will be performed 34-36 h after the administration of HCG.

After fertilization, biopsy was obtained from cleavage stage embryos. FISH analysis was used to distinguish embryos with balanced and unbalanced chromosomal abnormalities for carriers of structural chromosomal aberrations. In the analysis of translocations, unique FISH probes that flank the breakpoints of each translocation or that require the use of subtelomeric probes (specific to the chromosome ends of the translocated segments) for each affected individual must be designed and validated to detect normal and balanced products in embryonic tissue.

The principle of PGD by FISH is that target-specific DNA probes labelled with different fluorochromes or haptens can be used to detect the copy number of specific loci, and thereby to detect chromosome imbalance associated with meiotic segregation of chromosome rearrangements which includes the Robertsonian translocations, reciprocal translocations, inversions, and complex rearrangements. FISH can also be used to select female embryos in families with X-linked disease Polymerase chain reaction (PCR) has been used to diagnose monogenic disorders. PCR is used to amplify sufficient DNA from embryo cells . A blastomere is placed in a solution that lyses the cell and releases the DNA and the PCR reaction mix is then added to begin the PCR. Because of its high sensitivity, contamination of the study sample with extraneous DNA is a danger and has led to the adoption of rigorous laboratory procedures and standards, such as the use of intracytoplasmic sperm injection.

PGD analysis results were available on day 5 after oocyte retrieval. If possible, 2 unaffected embryos were transferred and the rest of the unaffected embryos were cryopreserved.