What is the most appropriate investigation before prescribing contraception to a 41-year-old woman with no abnormal uterine bleeding or menstrual irregularities?

No Routine Investigation Required Before Prescribing Contraception

A pelvic examination or any imaging study is not necessary before prescribing most forms of contraception to this 41-year-old woman with no abnormal uterine bleeding or menstrual irregularities. 1

Guideline-Based Approach

No Investigation Needed for Most Contraceptive Methods

• The American Academy of Pediatrics explicitly states that a speculum or bimanual examination is unnecessary before prescribing most forms of contraception, including oral contraceptive pills, the contraceptive patch, ring, progestin-releasing implant, and medroxyprogesterone injections. 1

• The package insert for oral contraceptive pills specifically states that a gynecologic examination is not necessary, as there is nothing that would be found on pelvic examination that would contraindicate prescribing oral contraceptive pills. 1

• A urine-based pregnancy test and STI screen can be performed if indicated, but imaging or hormonal testing is not required. 1

Exceptions Requiring Examination

• The only two contraceptive methods requiring examination are an intrauterine device (IUD) or diaphragm, for which anatomic variation could affect insertion or appropriate sizing of the device. 1

Why the Listed Options Are Inappropriate

FSH (Option A)

• FSH is not routinely recommended in the initial workup for reproductive-age women requesting contraception. 2
• FSH may be relevant only for perimenopausal assessment, which is not indicated in this asymptomatic 41-year-old woman. 2

TSH (Option B)

• TSH should be checked as part of the diagnostic workup for abnormal uterine bleeding, not for routine contraception prescription. 2, 3
• This patient has no AUB or menstrual irregularities, making TSH testing unnecessary. 2

Transvaginal Ultrasound (Option C)

• Transvaginal ultrasound is the first-line imaging study to identify structural causes of abnormal uterine bleeding, such as polyps, adenomyosis, leiomyomas, and endometrial pathology. 1, 2, 4
• This investigation is indicated only when AUB is present or suspected, not for routine contraception prescription. 2, 4

Endometrial Biopsy (Option D)

• Endometrial biopsy should be performed in perimenopausal women with risk factors for endometrial cancer or when ultrasound findings warrant tissue diagnosis. 2
• This is not a first-line investigation for asymptomatic women requesting contraception. 2

Clinical Algorithm for Contraception Prescription

For this asymptomatic 41-year-old woman:

1. Perform pregnancy test (urine β-hCG) if clinically indicated based on sexual activity and contraceptive history. 2

2. Take focused history regarding contraindications to specific contraceptive methods (smoking, cardiovascular disease, thrombotic risk, migraine with aura). 1

3. Prescribe appropriate contraception without requiring pelvic examination, imaging, or hormonal testing. 1

4. Reserve examination/imaging only if the patient chooses an IUD or diaphragm, or if she develops abnormal bleeding or other gynecologic symptoms. 1

Common Pitfalls to Avoid

• Do not delay contraception by ordering unnecessary investigations in asymptomatic women, as this creates barriers to access and increases unintended pregnancy risk. 1

• Do not confuse the workup for abnormal uterine bleeding (which requires transvaginal ultrasound, TSH, and potentially endometrial sampling) with routine contraception prescription. 2, 3

• Do not perform routine pelvic examinations before hormonal contraception, as this outdated practice is not evidence-based and may deter women from seeking contraception. 1

Answer: None of the above options (A, B, C, or D) are appropriate investigations before prescribing contraception to this asymptomatic woman.