Contraception

• There are different categories of contraception including sterilisation, hormonal, coitus interruptus, fertility awareness, and others.
• Hormonal contraception includes progestogen only and combined oestrogen & progestogen.
• COCP preparations are a type of hormonal contraception.
• Rang and Dale’s Pharmacology 9 th Edition Chapter 36
• FSRH Guidelines – Combined Hormonal Contraception (July 2019) https://www.fsrh.org/standards-and-guidance/documents/combined-hormonal-contraception/
• Trussell J
• Postcoital pills and copper-bearing IUCDs are widely used forms of emergency contraception.
• Contraceptive failure in the United States
• Contraception 2011;83:397–404.
• Emergency contraception is a method of emergency contraception.
• The perfect contraceptive would be 100% reliable, 100% safe, non user dependent, unrelated to coitus, visible to the woman, with no ongoing medical input, completely reversible within 24 hours, and with no discomfort.
• Hormonal contraceptives prevent pregnancy via the inhibition of ovulation, thinning of the endometrium, alteration of tubal motility and cervical mucus thickness.
• Combined oral contraceptive pills (COCPs) exist in different preparations: monophasic, biphasic and triphasic.
• Hormonal contraceptives exist in two formulations: the combined oestrogen and progestogen contraceptive, and the progestogen only contraceptive.
• There are three main categories of contraception: sterilisation, hormonal and pericoital contraception.
• Hormonal contraceptives also have non-contraceptive uses/benefits.
• Categories of contraception include sterilisation, vasectomy, tubal ligation, hormonal, coitus interruptus, fertility awareness, vas deferens, urethra, bladder, prostate, IUD, injection or pill, implant, vaginal ring, condoms, diaphragm, sponges, spermicide, and transdermal patch.
• The UK Family Planning Association (FPA) states that healthcare costs associated with unwanted pregnancies far outweigh the cost of making contraceptives free and widely available to the population.
• Hormonal contraception works by altering the ovarian steroid production responsible for cyclic changes within the endometrium.
• Oestrogen is responsible for the changes during the Follicular/Proliferative Phase of the menstrual cycle, including the thickening of the endometrium, the growth of endometrial glands, and the emergence of spiral arteries.
• Progesterone is responsible for the changes during the Luteal/Secretory Phase of the menstrual cycle, including increased growth of spiral arteries, increased secretion of mucus by endometrial glands, and endometrium receptive to implantation.
• Monophasic and multifaceted COCP preparations are types of hormonal contraception.
• The perfect contraceptive does not exist.
• The latest generation of Progestogens is derived from Spironolactone and is known as Drospirenone.
• Drug interactions with Progestogen-only contraceptives include increased metabolism/decreased efficiency with antibiotics, anti-seizure medication, HIV protease inhibitors, and St John’s wort.
• Progesterone acts on the Supra-physiological levels to cause “Pseudo-pregnancy”, suppressing the HPG axis.
• The risks/side effects of Progestogen-only contraceptives include breakthrough bleeding in some, and relative contraindications such as BMI>35, migraine without aura, hypertension, diabetes, hyperprolactinoma.
• Oestrogen acts on the Anterior pituitary & Hypothalamus to suppress GnRH and Gonadotrophins, inhibiting ovulation.
• Progesterone acts on the Endometrium to cause a constant dose of progesterone to result in endometrial thinning, making it unreceptive to implantation.
• The benefits of Progestogen-only contraceptives include reliability, safety, unrelatedness to coitus, woman in control, rapid reversibility, and ability to help conditions such as endometriosis, premenstrual syndrome, dysmenorrhoea, menorrhagia.
• Progestogens are older generation Progestogens such as Norethisterone (Norethindrone) and Levonorgestrel.
• Oestrogen is Ethinyloestradiol and it is available in doses of 20, 30, 35, 50mcg.
• Combined Oestrogen & Progestogen contraceptives include products such as Yasmin, Yaz, Marvelon, Loestrin, and Levlen.
• Progesterone acts on the Anterior pituitary & Hypothalamus to suppress GnRH and Gonadotrophins, inhibiting ovulation.
• Newer generation Progestogens include Desogestrel, Gestodene and Norgestimate (Noregestromin).
• Progesterone also acts on the Fallopian tubes to alter tubal ciliary action and tubal muscle contractility.
• Progesterone acts on the Cervical mucus to thicken it, serving to prevent sperm entry.
• Noristerat is a progestogen used in the NET and is released into circulation for about 5 years.
• Progestogen only contraceptives act on the anterior pituitary and hypothalamus, resulting in a decrease in GnRH and gonadotrophins.
• Norethisterone is a progestogen used in the Mini Pill and is released into circulation for about 5 years.