A pre-coital pill? A preliminary in vitro study

Abstract

Summary

FSRH Guideline (April 2019) Overweight, Obesity and Contraception

“…Data from an exploratory in vitro study of 16 women123 found that a single tablet of LNG 30 μg (n=8) or NET 350 μg (n=8) prevented sperm migration in cervical mucus 12 hours after ingestion, including in the three women who had a BMI >35 kg/m 2 123. As this study only examined the impact of a single POP dose, further evidence is required before conclusions can be drawn about the impact of weight or BMI on the cervical mucus effect of POPs.…”

FSRH Guideline (August 2022) Progestogen-only Pills

“…The changes in cervical mucus – reduced volume, increased viscosity and cellularity – and altered molecular structure7–9 are unfavourable to sperm penetration into the upper reproductive tract. This ‘hostile’ mucus is achieved rapidly after starting a POP9,10 even if cervical mucus is initially very favourable at the time that the POP is taken 9. It is accepted practice that 2 days of pill-taking is sufficient to achieve this element of contraceptive protection.…”

FFPRHC Guidance (July 2005): The use of contraception outside the terms of the product licence

“…35 Sixteen women were randomly allocated to take levonorgestrel pills or norethisterone pills 2-3 days before ovulation. 36 Cervical mucus quality and sperm contraceptive efficacy. Studies in primates have shown that the COC can effectively inhibit ovulation even when started up to and including Day 6.…”