A patient asks about the mechanism of emergency contraception. What should the nurse explain?

Adolescentsrequire tailored contraceptive counseling due to high rates of unintended pregnancy, variable adherence, limited knowledge, and developmental factors. They often face barriers such as lack of access, confidentiality concerns, and misinformation. The adolescent pregnancy rate remains significantly higher than other age groups, with unintended pregnancy rates exceeding 80% in some populations. Normal menstrual cycles may be irregular in early adolescence, complicating fertility awareness methods. Cognitive and emotional maturity also influences decision-making and consistency in contraceptive use. Long-acting reversible contraceptives (LARCs) are recommended due to their high efficacy and low maintenance.

Rationale for correct answers

2.Adolescents have the highest rates of unintended pregnancy due to inconsistent contraceptive use, limited access, and developmental factors. Tailored counseling improves method selection, adherence, and understanding, reducing risk.

Rationale for incorrect answers

1.Postmenopausal women are not at risk of pregnancy due to cessation of ovulation. Their counseling focuses on hormone replacement therapy and other health concerns, not contraception.

3.Women over 50 years typically have declining fertility due to reduced ovarian reserve and anovulatory cycles. While contraception may be needed until menopause is confirmed, their risk of unintended pregnancy is much lower than adolescents.

4.Nulliparous women may have specific considerations for method selection (e.g., IUD insertion technique), but they do not inherently have higher unintended pregnancy risk. Counseling may be individualized but not necessarily tailored due to elevated risk.

Take home points

• Adolescents have the highest unintended pregnancy risk
• Tailored counseling improves contraceptive adherence and understanding
• Postmenopausal and older women have low fertility risk
• Nulliparity affects method choice, not pregnancy risk

Emergency contraception works by interfering with ovulation, fertilization, or implantationdepending on the type and timing of administration. The most common forms include levonorgestrel and ulipristal acetate. Levonorgestrel inhibits LH surge, preventing ovulation, while ulipristal delays follicular rupture. Normal serum LH levels range from 5–25 IU/L during the mid-cycle surge. These agents do not affect an already implanted embryo and are ineffective once pregnancy is established. Side effects include nausea, headache, and menstrual irregularities. Contraindications include known pregnancy and hypersensitivity to components.

Rationale for correct answers

2.Emergency contraception prevents ovulation or fertilization. Levonorgestrel inhibits the luteinizing hormone surge, blocking ovulation if taken before the peak. Ulipristal acetate delays follicular rupture. These mechanisms act before fertilization, making this the correct explanation.

Rationale for incorrect answers

1.Emergency contraception does not terminate an established pregnancy. It is ineffective once implantation has occurred. Agents like mifepristone are used for termination, not levonorgestrel or ulipristal. Emergency contraception is not abortifacient.

3.Endometrial shedding is not the primary mechanism. While some thinning of the endometrium may occur, it is not reliable or consistent enough to prevent implantation. The dominant action is inhibition of ovulation.

4.Emergency contraception does not immobilize sperm permanently. Sperm motility is unaffected by these agents. Barrier methods or spermicides are used to impair sperm movement, not hormonal emergency contraception.

Take home points

• Emergency contraception prevents ovulation or fertilization, not implantation.
• It is ineffective once pregnancy is established.
• It does not cause permanent sperm immobilization.
• It must be differentiated from abortifacients like mifepristone.