Hormonal contraceptives

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 hormonal contraceptives ^[1][2][3]

Intrauterine devices ^[5]

General

• Small, t-shaped birth control devices inserted into a woman's uterus to prevent pregnancy
• In the United States, they are available in two forms: nonhormonal copper-containing devices and plastic devices with progestogen hormones.
• Inserted through a quick clinical procedure
• Individuals must be tested for pregnancy and STIs before insertion.

Types

• Copper intrauterine device: see “Intrauterine device” in “Nonhormonal contraception.”
• Progestin intrauterine device: a progestin-releasing (e.g., levonorgestrel-releasing) contraceptive device that is placed into the uterus
  • Mechanisms ^[6]
    • Produces local inflammatory reaction → prevents fertilization and implantation
    • Interferes with sperm function and transport
    • See “Progestin” in “Pharmacodynamics” below.
  • Characteristics
    • ≥ 99% effective in preventing pregnancy ^[7]
    • Provides long-term, reversible contraception: contraceptive activity lasts up to 5 years if kept in place after insertion.
    • Less menstrual bleeding or amenorrhea compared to copper IUDs

Adverse effects

• Abnormal uterine bleeding and/or menstrual changes
• Dysmenorrhea
• Pelvic pain following insertion
• Uterine perforation

Contraindications

• Active PID
• Known or suspected pregnancy
• Anatomical uterine abnormalities
• Gestational trophoblastic disease
• Cervical or endometrial precancerous lesions or carcinoma
• Symptomatic STIs within the last 3 months
• Breast cancer (progestin IUD)

Emergency contraception

See “Emergency contraception” for more information.

Mechanisms of action depend on the hormones used in the formulation.

• Estrogen
  • Hypothalamus: supresses release of GnRH
  • Pituitary: suppresses release of gonadotropins
    • Decreased LH production and release leads to inhibition of ovulation.
    • Decreased FSH level prevents ovarian folliculogenesis.
• Progestin: synthetic progesterone
  • 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 causes inhibition or delay of ovulation, suppression of endometrial maturation, and pregnancy termination

Common side effects

• Estrogen:
  • Venous thromboembolism (VTE): increased rate due to estrogen-mediated coagulopathy ^[8]
  • Cardiovascular events
  • Hypertension: increased risk in patients with a history of HTN during pregnancy and/or family history of HTN
  • Headaches
  • Hepatic adenoma development
  • Mastopathy and mastodynia
  • Nausea, GERD ^[9]
• Progestin:
  • Breakthrough bleeding
  • Follicular cysts
• Weight gain is not a side effect of hormonal contraceptives

Indications for immediate discontinuation ^[10]

• Sensory disorders (e.g., impaired vision)
• Detection of masses
  • Fibroid growth
  • Breast lump growth
• New or enhanced migraine-like headaches (especially with aura)
• New or enhanced epilepsy
• Jaundice
• Pregnancy
• Suspected thromboembolism or thrombophlebitis

Studies have shown that women taking estrogen-progestin combination OCPs before menopause have an increased risk of cervical carcinoma but a decreased risk of endometrial and ovarian carcinoma.

We list the most important adverse effects. The selection is not exhaustive.

Contraceptive indications

• Patients desiring pregnancy in 1–2 years
  • Short-acting reversible options include OCPs, patches, and vaginal rings
  • DMPA provides relatively long protection (up to 3 months) but is not appropriate for patients who wish to regain fertility quickly.
  • 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.
  • OCPs containing estrogen should not be given if breastfeeding (estrogen may reduce breast milk production and enter the milk itself).
  • Combination OCPs may only be used after 4–6 weeks postpartum.

Non-contraceptive indications ^[5]

• Symptomatic treatment in abnormal uterine bleeding
• Polycystic ovary syndrome (PCOS)
• Hyperandrogenism
  • Acne
  • Hirsutism
• Pelvic pain due to endometriosis
• Menstrual migraine
• Premenstrual dysphoric disorder (PMDD)
• Benign breast cysts
• Dysmenorrhea
• Mittelschmerz

Absolute contraindications for estrogen-containing OCPs

• Cardiovascular
  • Thromboembolism
  • Coagulopathy, antiphospholipid antibodies
  • Coronary heart disease
  • Stroke
  • Arterial hypertension (> 160/95 mm Hg)
  • Heart defects
• Metabolic
  • Pronounced hypertriglyceridemia
  • Metabolic disorders of the liver
  • Insulin-dependent diabetes mellitus with vascular complications or duration greater than 20 years
• Oncologic
  • Hepatic tumors
  • Estrogen-dependent tumors (e.g., breast cancer)
• Inflammatory
  • Acute pancreatitis
  • Lupus erythematosus
  • Vasculitis
  • After herpes gestationis
• Other
  • Smoking > 35 years of age (due to significant increase in the risk of VTE)
  • Genital bleeding of unknown cause
  • Pregnancy
  • Migraine with aura

Women who smoke and are > 35 years old should not be prescribed OCPs because of increased risk of cardiovascular side effects!

Relative contraindications for estrogen-containing OCPs

• Cardiovascular
  • Superficial venous thrombosis
  • Thrombophlebitis
  • Severe varicosis
• Metabolic
  • Hypercholesterolemia
  • Morbid obesity
  • Diabetes mellitus
• Other
  • Age > 40 years
  • Migraines
  • Uterine leiomyomas (especially intracavitary)
  • Epilepsy
  • Smoking
  • Lactation (progestin-only preparations permitted): otherwise ↑ risk of thromboembolism due to estrogen excess
  • Ulcerative colitis

We list the most important contraindications. The selection is not exhaustive.

Minors

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.