What is the function of estrogen in preparing the uterine lining during the menstrual cycle?

Correct Answer: B

Rationale: The correct answer is B. Estrogen plays a crucial role in thickening and vascularizing the endometrium to prepare for potential implantation of a fertilized egg. Estrogen does not prevent ovulation (choice A), as it actually promotes ovulation. It also does not directly stimulate egg release (choice C), as that is primarily controlled by luteinizing hormone. Estrogen indirectly influences progesterone production by triggering ovulation, but it does not directly increase progesterone production (choice D).

Correct Answer: B

Rationale: The correct answer is B because luteal phase deficiency is caused by insufficient progesterone to maintain the uterine lining, which is crucial for implantation of a fertilized egg. This deficiency can lead to difficulty in sustaining a pregnancy. A is incorrect because estrogen levels are more related to follicular phase than luteal phase. C is incorrect because luteal phase deficiency can occur in women without PCOS. D is incorrect because immature eggs are more related to ovulation issues rather than luteal phase deficiency.

Correct Answer: B

Rationale: The correct answer is B because embryo freezing allows for future pregnancy attempts without additional egg retrieval. This is important as it saves time, cost, and reduces physical burden on the patient. Choice A is incorrect as success rates are similar for frozen and fresh embryos. Choice C is incorrect because hormonal support is still required during IVF with frozen embryos. Choice D is incorrect as genetically unmodified embryos can also be frozen.

Correct Answer: A

Rationale: Correct Answer: A Rationale: 1. Transferring multiple embryos increases the chance of multiple pregnancies, which can lead to complications such as preterm birth and low birth weight. 2. This is an important consideration for the couple undergoing IVF to understand the potential risks involved. 3. Single embryo transfers reduce the risk of multiples and associated complications. 4. Choices B, C, and D are incorrect as they provide inaccurate information that contradicts the known risks associated with multiple pregnancies.

Correct Answer: B

Rationale: The correct answer is B because sperm count, motility, and morphology are indeed critical factors in male fertility. Sperm count refers to the number of sperm present, motility is the ability of sperm to move effectively, and morphology relates to the shape and structure of sperm. These factors directly impact a man's fertility potential. Choice A is incorrect because male infertility can have various causes, not solely low testosterone levels. Choice C is incorrect as male infertility can impact the success of fertility treatments. Choice D is incorrect because semen analysis is a key diagnostic tool for identifying male factor infertility.