In a 41-year-old asymptomatic woman requesting contraception, what is the most appropriate investigation before prescribing contraception?

Blood Pressure Measurement Only

For a healthy 41-year-old asymptomatic woman requesting contraception, blood pressure measurement is the only essential investigation required before prescribing combined hormonal contraceptives, and no investigations are needed for progestin-only methods. 1

Essential Investigations by Contraceptive Method

Combined Hormonal Contraceptives (Pills, Patch, Ring)

• Blood pressure measurement is the sole mandatory examination (Class A - essential and mandatory in all circumstances) before initiating combined hormonal contraceptives 1, 2, 3
• Women with severe hypertension (≥160/100 mmHg) should not use combined hormonal contraceptives (U.S. MEC 4), and those with less severe hypertension (140-159/90-99 mmHg) generally should not use them (U.S. MEC 3) 1
• Blood pressure can be obtained in non-clinical settings (pharmacy, fire station) and self-reported if healthcare access is limited 1, 2
• Weight/BMI measurement is optional but may be useful for baseline monitoring 1, 4

Progestin-Only Methods

• No examinations or laboratory tests are required before initiating progestin-only pills, implants, or injectable contraceptives 1, 4, 3

Intrauterine Devices (IUDs)

• Bimanual examination and cervical inspection are required for proper IUD placement 2, 4, 3

Investigations That Are NOT Needed

The CDC explicitly classifies the following as Class C examinations/tests (not contributing substantially to safe and effective contraceptive use) 1:

• FSH testing - Not required or recommended 1
• TSH testing - Not required or recommended 1, 4
• Transvaginal ultrasound - Not required 1
• Endometrial biopsy - Not required 1
• Pelvic examination (except for IUD insertion or diaphragm fitting) 1, 2
• Cervical cytology (Pap smear) 1, 2
• Clinical breast examination 1, 2
• Laboratory tests including glucose, lipids, liver enzymes, hemoglobin, and thrombogenic mutations 1, 4
• HIV screening 1, 4
• STI screening (unless clinically indicated by risk factors) 1, 2, 4

Critical Clinical Pitfalls to Avoid

Requiring unnecessary examinations creates significant barriers to contraceptive access, particularly for adolescents and low-income women who have high rates of unintended pregnancies 1, 2

The American Academy of Family Physicians specifically recommends not requiring a pelvic exam or other physical exam to prescribe oral contraceptive medications 2

A 2021 national survey found that 16-23% of providers incorrectly required unnecessary pelvic examinations before non-intrauterine hormonal method initiation, and 14-33% required unnecessary clinical breast examinations, Pap smears, or STI screening 5

Answer to the Question

None of the listed options (FSH, TSH, transvaginal ultrasound, or endometrial biopsy) are appropriate investigations before prescribing contraception to this healthy, asymptomatic 41-year-old woman. The only essential investigation would be blood pressure measurement if combined hormonal contraceptives are being considered 1, 2, 4