Reproductive Health Set-6

Q1. A couple simultaneously uses a male condom and a combined oral contraceptive. Typical‑use annual failure rates are $p_1=0.15$ for the condom and $p_2=0.05$ for the pill. Assuming the failures are independent, the annual probability of pregnancy for this couple is closest to:

Q2. In an IVF cycle two embryos are transferred and each embryo implants independently with probability $p=0.35$. The probability that at least one embryo implants equals:

Q3. A fertility clinic estimates the per‑embryo implantation probability for a 40‑year‑old woman as $p=0.20$. If the clinic transfers two embryos instead of one, calculate (i) the increase in the chance of at least one implantation (in percentage points) and (ii) the probability of a twin pregnancy (both implanting). Choose the pair that is closest to the correct values.

Q4. Under normal conditions (both fallopian tubes patent) a woman's probability of conception per cycle is $p=0.20$. Ovulation occurs equally likely from left or right ovary. If the left tube is completely blocked but the right tube can capture an ovum released from the left ovary with probability $c=0.10$ (contralateral pickup), and if whenever an ovum is captured the chance of conception in that cycle remains $p$, the new probability of conception per cycle is approximately:

Q5. An intrauterine insemination (IUI) treatment confers a per‑cycle conception probability $p=0.12$, independent between cycles. Couples aim for at least an $80\%$ cumulative probability of conceiving with repeated IUI cycles. What is the minimum integer number $n$ of cycles required so that $1-(1-p)^n \ge 0.80$?

Q6. A contraceptive method reduces the number of sperm reaching the ovum by $80\%$. If without contraception the probability of conception per cycle is $0.30$, what is the expected probability of conception per cycle when this method is used (assume the reduction acts multiplicatively)?

Q7. A 32‑year‑old woman with regular ovulation and normal ovarian reserve is investigated for primary infertility. Her husband's semen analysis is normal, but hysterosalpingography shows bilateral blockage of both fallopian tubes. Which assisted reproductive technique is the most appropriate to achieve pregnancy in this couple?

Q8. A 29‑year‑old woman, breastfeeding at 6 weeks postpartum, requests an oral contraceptive. She reports a past history of deep vein thrombosis (DVT) while taking a combined (estrogen–progestin) oral contraceptive. Which oral contraceptive is the safest and most appropriate choice for her now?

Q9. Assertion (A): Copper‑bearing intrauterine devices (Cu‑IUDs) prevent pregnancy primarily by preventing implantation of a fertilized ovum.
Reason (R): Copper ions released from the IUD are toxic to sperm and the device induces a local inflammatory response in the uterus that impairs sperm motility and viability.

Q10. In an antenatal screening population the ELISA test for HIV has sensitivity $Se=99.5\%$ and specificity $Sp=98.5\%$. If the prevalence of HIV in this population is $P=1\%$, compute the positive predictive value (PPV), where $PPV=\dfrac{Se\times P}{Se\times P + (1-Sp)\times(1-P)}$. Approximately what is the probability that a pregnant woman with a positive ELISA is truly infected?

Q11. A couple uses a male condom as contraception. If the per‑act probability of condom failure (breakage/slippage leading to potential exposure) is $p=0.02$ and they have $n=20$ acts of intercourse, then assuming independence between acts the probability of at least one failure is $1-(1-p)^n$. What is this probability (approximately)?

Q12. A couple has been trying to conceive for 2 years. Semen analysis of the male partner shows sperm concentration = 80 million/ml and normal morphology = 60%, but progressive motility = 0% (no motile sperm detected). The female partner has regular ovulation and normal reproductive evaluation. Which assisted reproductive technique is the most appropriate to achieve fertilization using the couple’s own gametes?

Q13. Assertion (A): Levonorgestrel‑based emergency contraceptive pills prevent pregnancy primarily by inhibiting or delaying ovulation and do not terminate an established pregnancy. Reason (R): Levonorgestrel’s main contraceptive effect is mediated by causing significant endometrial changes that prevent implantation of a fertilised ovum.

Q14. Typical‑use annual failure rates are: male condom $p_1=0.18$ and combined oral contraceptive pill $p_2=0.09$. Assuming failures of the two methods are independent and that pregnancy occurs only if both methods fail simultaneously, the annual probability of pregnancy when both are used together is given by $p_{\text{preg}}=p_1\times p_2$. What is the approximate annual probability of pregnancy in this case?

Q15. A couple are both carriers of a severe autosomal recessive disorder. They want a genetically related child but are strongly opposed to termination of pregnancy at any stage. Which reproductive option best minimises the chance of having an affected child while respecting their wish to avoid termination and retain genetic relatedness?