A comprehensive analysis of chromosomal polymorphic variants in females and males in the outcome of ICSI

Ralapanawe, Madara Sapumal Bandara ORCID: 0000-0003-1798-7115 (2022). A comprehensive analysis of chromosomal polymorphic variants in females and males in the outcome of ICSI. University of Birmingham. Ph.D.

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Abstract

Infertility affects approximately one in eight couples worldwide. Intra cytoplasmic sperm injection (ICSI) is an assisted reproduction procedure in which a single sperm cell is injected directly into the cytoplasm of an egg and is first line treatment for many infertile couples. The live birth rate per ICSI cycle remains low, with over half a million couples remaining childless. Chromosomal polymorphisms are up to five times more common in couples with infertility compared to the general population. Although chromosomal polymorphisms are considered normal variations, some studies suggest they may be associated with adverse fertility outcomes.

To synthesise the existing evidence, I carried out a systematic review and meta-analysis of ten observational studies. I found that there was a slightly higher miscarriage rate observed in female carriers of chromosomal polymorphic variations compared to male carriers. However, the review did not find any adverse effects on rates of pregnancy, clinical pregnancy, on-going pregnancy at study end, pre-term birth and live birth. My main study analysed the chromosomal polymorphic variations of 942 ICSI and frozen embryo transfer (FET) cycles in Sri Lanka. Further, an analysis of types of chromosomal polymorphic variations based on gender, number of polymorphisms and their variants appear to have no adverse effect on reproductive outcomes compared to the couples without chromosomal polymorphism. Hence, my work concluded that chromosomal polymorphisms are unlikely to be associated with adverse reproductive outcomes.

Apart from chromosomal polymorphic variations with routine karyotyping, I found structural chromosomal abnormalities that were important to diagnose before the ICSI procedure. Hence, routine karyotyping before the ICSI procedure may still have a role outside the research context.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):