Genetics_of_Abortion_and_Infertility.pptx

- Summary of genetic factors in abortion and infertility
- Importance of genetic screening and counseling
- Role of nurses in patient education and support
- Future of reproductive genetics and emerging technologies

1. Genetics of Abortion and Infertility B.Sc. Nursing (Hons) - 2nd Year Lecture Presentation Duration: 60 minutes

2. Introduction - Definition of Abortion and Infertility - Importance of Genetics in Reproductive Health - Role of Genetic Factors in Abortion and Infertility

3. Genetics of Abortion - 50-60% of first-trimester abortions are due to genetic abnormalities - Chromosomal abnormalities, single-gene mutations - Role of parental genetic factors

4. Types of Genetic Abnormalities in Abortion - Aneuploidy (Trisomy 21, Trisomy 18, Monosomy X) - Structural chromosomal abnormalities (translocations, deletions) - Polyploidy (Triploidy, Tetraploidy) - Single-gene disorders and epigenetic factors

5. Chromosomal Abnormalities in Miscarriages Prevalence: Chromosomal abnormalities are found in over 50% of first-trimester miscarriages. Less common in second- and third-trimester losses. Types of Abnormalities: Numerical abnormalities (aneuploidy): Caused by chromosomal nondisjunction during meiosis. Examples: Autosomal trisomies (30%–60%, e.g., trisomy 21). Triploidy (11%–13%). Monosomy X (10%–15%, Turner syndrome). Tetraploidy (9%). Structural abnormalities: Translocations, deletions, duplications (2%–6%). Mosaicism: Presence of two or more cell lines with different chromosomal makeup (8%).

6. Chromosomal Abnormalities in Miscarriages Origin of Abnormalities: Most arise  de novo  (spontaneously) during gametogenesis. Errors include nondisjunction, translocations, deletions, duplications, or insertions. Impact on Embryos: Chromosomal imbalances in oocytes or sperm lead to abnormal embryos, often resulting in miscarriage. Some abnormalities (e.g., trisomy 21, monosomy X, balanced translocations) are compatible with life. Genetic and Epigenetic Factors: Defects in genes regulating meiosis, DNA repair, or cell proliferation can impair gamete and embryonic development. Epigenetic modifications and imprinting disorders during gametogenesis may also contribute to miscarriage. Clinical Relevance for Nurses: Understanding these mechanisms aids in counseling and supporting families experiencing pregnancy loss.

7. Parental Age and Miscarriage Risk Female Age: Strongest risk factor for miscarriage. Highest risk at extremes of reproductive age (<20 and ≥40 years). In women ≥40, genetic abnormalities in oocytes and embryos are the leading cause of pregnancy loss. Paternal Age: Risk of miscarriage increases with age. Men ≥40 have 69% higher odds of miscarriage compared to men aged 20–29. Contributing factors: Decline in reproductive function (e.g., lower testicular activity, hormonal changes). Increased sperm chromosomal abnormalities, DNA damage, gene mutations, and epigenetic defects. Elevated reactive oxygen species and impaired DNA repair mechanisms.

8. Genetic Testing for Pregnancy Loss - Karyotyping (Chromosomal Analysis) - Chromosomal Microarray Analysis (CMA) - Next-Generation Sequencing (NGS) - Preimplantation Genetic Testing (PGT-A, PGT-M, PGT-SR)

9. Nursing Role in Genetic Counseling for Abortion - Psychological support for patients - Preconception screening and education - Referral for genetic counseling - Ethical considerations in pregnancy loss

10. Genetics of Infertility - 30-50% of infertility cases have a genetic basis - Male vs. Female genetic infertility factors - Advances in reproductive genetics

11. Genetic Causes of Male Infertility - Klinefelter Syndrome (47,XXY) - Y-chromosome microdeletions (AZFa, AZFb, AZFc) - Androgen Insensitivity Syndrome - Cystic Fibrosis-related infertility

12. Genetic Causes of Female Infertility - Turner Syndrome (45,X0) - Fragile X Premutation (FMR1 gene expansion) - Polycystic Ovary Syndrome (PCOS susceptibility genes) - Mitochondrial DNA mutations

13. Genetic Testing for Infertility - Karyotyping (Detects chromosomal abnormalities) - Y-chromosome microdeletion testing - CFTR gene testing (Cystic Fibrosis) - Preimplantation Genetic Testing (PGT)

14. Case Studies and Discussion - Case 1: Recurrent miscarriages due to balanced translocation - Case 2: Azoospermia and Y-chromosome microdeletion - Case 3: Early menopause and Fragile X Premutation - Ethical considerations and nursing interventions

15. Conclusion - Summary of genetic factors in abortion and infertility - Importance of genetic screening and counseling - Role of nurses in patient education and support - Future of reproductive genetics and emerging technologies