Question 1: In Vitro Fertilisation (IVF) is a process used to assist couples struggling with infertility. It involves fertilising an egg outside the body and then implanting the embryo into the uterus. Explain the main scientific principle behind IVF.

Answer: IVF relies on fertilising an egg outside the body using sperm in a laboratory setting, then transferring the resulting embryo into the uterus to achieve pregnancy.

Question 2: Describe the primary steps involved in the IVF process from egg retrieval to embryo implantation.

Answer: The main steps include stimulating the ovaries to produce multiple eggs, retrieving the eggs, fertilising them with sperm in the laboratory, culturing the embryos, selecting the healthiest embryo(s), and implanting them into the woman's uterus.

Question 1: Define 'embryo culture' in the context of IVF.

Answer: Embryo culture is the process of growing fertilised eggs in a laboratory environment until they reach a suitable stage for implantation.

Question 2: What is ovarian hyperstimulation, and why is it used in IVF?

Answer: Ovarian hyperstimulation involves using hormones to produce multiple eggs in a cycle, increasing the chances of successful fertilisation and pregnancy in IVF.

Question 1: If the success rate of IVF per cycle is 30%, how many cycles are needed on average to have a 90% chance of at least one successful pregnancy? (Use the formula: P = 1 - (1 - success rate)^number of cycles).

Answer: Number of cycles = log(1 - desired probability) / log(1 - success rate). For 90% success, number of cycles = log(0.1) / log(0.7) ≈ 4.95, so approximately 5 cycles.

Question 1: Identify three safety precautions that should be observed during the laboratory handling of eggs and sperm in IVF.

Answer: Using sterile techniques to prevent contamination, maintaining correct temperature and pH levels, and wearing protective clothing to avoid biological contamination.

Question 2: Describe a key variable that must be controlled during embryo culture and explain its importance.

Answer: Temperature must be precisely controlled, typically around 37°C, to ensure proper embryo development.

Question 1: A clinic reports that out of 200 IVF cycles performed, 60 resulted in successful pregnancies. Calculate the success rate per cycle and comment on its implications for prospective patients.

Answer: Success rate = (Number of successful pregnancies / Total cycles) × 100 = (60 / 200) × 100 = 30%. This indicates that approximately 30% of cycles result in pregnancy, so patients should consider multiple cycles for higher chances.

Question 1: Discuss the ethical considerations associated with IVF, including both benefits and potential concerns. Your answer should consider societal, moral, and medical perspectives.

Answer: Ethical considerations of IVF include the moral debate over embryo selection and disposal, access and affordability, and potential for genetic modification. Benefits include giving infertile couples the opportunity to have children and advancing reproductive technology. Concerns involve the ethical implications of manipulating human embryos, possible exploitation, and societal impacts such as increased genetic 'selection'. It is important to balance scientific progress with ethical responsibility.

Question 1: Describe two ways in which IVF technology has influenced modern reproductive healthcare and society.

Answer: IVF has enabled many infertile couples to conceive, reducing childlessness. It has also advanced genetic research and embryo preservation techniques, shaping ethical debates and policies on reproductive rights.