Hormonal contraceptives involve the use of estrogen and progestin analogs to prevent pregnancy. The contraceptive effect is mediated by negative feedback at the hypothalamus, ultimately leading to reduced pituitary follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion. Without an LH surge, ovulation does not occur. Progestin also makes implantation less likely, as it causes a thickening of cervical mucus, a decrease in tubal motility, and the inhibition of endometrial proliferation. Oral contraceptives (OCs) are the most common form of hormonal contraception, but other forms of hormone delivery, including patches, injections, and implants, also exist. In combination monophasic OCs, the dose of estrogen and progestin remains constant, while in combination multiphasic OCs it varies over the course of one cycle. The decreased total hormone doses of multiphasic OCs mitigate certain associated side effects and risks. These include bothersome symptoms such as breast tenderness, nausea, bloating, and breakthrough bleeding as well as medical emergencies such as venous thromboembolism. Because of the complications associated with hormonal contraceptives, their use is contraindicated in patients with certain medical conditions and histories, e.g., significant hypertension, ischemic heart disease, venous thromboembolism, and stroke.
Types of oral contraceptives
|Overview of different types of hormonal contraceptives|
|Type||Description||Pregnancy rate in first year with typical use (with perfect use) ||Indications|
|Oral contraceptive pill||Combined oral contraceptive (COC)|| |
|Progestin-only contraceptive pills (minipill)|| |
|Contraceptive patch|| |
|Vaginal ring|| || |
|Injectable progestin|| || || |
|Intrauterine device with progestin|| || |
|Subdermal progestin implant|| || |
Non-hormonal methods: copper-containing
- Added benefit of long-term contraception
- Requires brief, clinical procedure
- Most effective when taken within 3 days of intercourse
- Typically administered as a single dose or as two doses over one day
- Significantly less effective in patients who are obese or overweight
Mechanisms of action depend on the hormones used in the formulation.
- Inhibits GnRH and LH secretion and thus suppresses ovulation (main contraceptive mechanism)
- Inhibits endometrial proliferation, thereby preventing the implantation of the embryo
- Changes cervical mucus (↓ volume and ↑ viscosity) and impairs fallopian tube peristalsis, thereby inhibiting sperm ascension and egg implantation
- Inhibits follicular maturation
- Antiprogestin: inhibition of the progesterone receptor cause inhibition or delay of ovulation, suppression of endometrial maturation, and pregnancy termination
Common side effects
- Weight gain is not a side effect of hormonal contraceptives
Indications for immediate discontinuation
- Sensory disorders (e.g., impaired vision)
- New or enhanced migraine-like headaches (especially with aura)
- New or enhanced epilepsy
- Detection of masses
- Suspected thromboembolism or thrombophlebitis
We list the most important adverse effects. The selection is not exhaustive.
Patients desiring pregnancy in 1–2 years
- Short-acting reversible options include OCPs, patches, and vaginal rings
- DMPA (progestin-only contraceptive that is typically injected and provides relatively long (up to 3 months) but reversible protection) is not appropriate for patients who wish to regain fertility soon.
- Implants and IUDs can be used but may not be cost-effective
- Postpartum contraception: All contraceptive options except for combination OCPs can be considered in the postpartum period.
Women who smoke and are > 35 years old should not be prescribed OCPs because of increased risk of cardiovascular side effects!
We list the most important contraindications. The selection is not exhaustive.
Special patient groups
In the United States, laws allowing minors to consent to contraceptive health care are determined by individual states. Most states allow adolescents to receive medical care related to pregnancy prevention without parental consent.