Emergency contraception

Emergency contraception
Emergency contraception
	An emergency contraception pill
Background
Type	Hormonal (progestin or others) or intrauterine
First use	1970s
Synonyms	Emergency postcoital contraception
Failure rates (per use)
Perfect use	ECP: see article text; IUD: under 1%
Typical use	% (please see Effectiveness of ECPs below)
Usage
User reminders	Pregnancy test required if no period seen after 3 weeks
Clinic review	Consider need for STI screening and ongoing birth control needs
Advantages and disadvantages
STI protection	No
Periods	ECP may disrupt next menstrual period by a couple of days. IUDs may make menstruation heavier and more painful
Benefits	IUDs may be subsequently left in place for ongoing contraception
Risks	As per methods
Medical notes
	Use as soon as possible.; Copper IUD within 5 to 10 days; Ulipristal acetate or mifepristone pill within 5 days; Levonorgestrel pill within 3 days; Yuzpe regimen (combined estrogen/progestin pills at higher doses) is no longer recommended unless other options are not available;

Emergency contraception (EC) is a birth control measure, used after sexual intercourse to prevent pregnancy.

There are different forms of EC. Emergency contraceptive pills (ECPs), sometimes simply referred to as emergency contraceptives (ECs), or the morning-after pill, are medications intended to disrupt or delay ovulation or fertilization, which are necessary for pregnancy.^[3]^[4]^[5]

Intrauterine devices (IUDs) – usually used as a primary contraceptive method – are sometimes used as the most effective form of emergency contraception.^[4]^[6] However, the use of IUDs for emergency contraception is relatively rare.^[1]

^ ^a ^b Cite error: The named reference Cle2014 was invoked but never defined (see the help page).
^ Cite error: The named reference Cle2012 was invoked but never defined (see the help page).
^ Leung VW, Levine M, Soon JA (February 2010). "Mechanisms of action of hormonal emergency contraceptives". Pharmacotherapy. 30 (2): 158–168. doi:10.1592/phco.30.2.158. PMID 20099990. S2CID 41337748.
^ ^a ^b Trussell J, Schwarz EB (2011). "Emergency contraception". In Hatcher RA, Trussell J, Nelson AL, Cates W Jr, Kowal D, Policar MS (eds.). Contraceptive technology (20th revised ed.). New York: Ardent Media. pp. 113–145. ISBN 978-1-59708-004-0. ISSN 0091-9721. OCLC 781956734. p. 121:
Mechanism of action
Copper-releasing IUCs
When used as a regular or emergency method of contraception, copper-releasing IUCs act primarily to prevent fertilization. Emergency insertion of a copper IUC is significantly more effective than the use of ECPs, reducing the risk of pregnancy following unprotected intercourse by more than 99%.^2,3 This very high level of effectiveness implies that emergency insertion of a copper IUC must prevent some pregnancies after fertilization.
Emergency contraceptive pills
To make an informed choice, women must know that ECPs—like the birth control pill, patch, ring, shot, and implant,⁷⁶ and even like breastfeeding⁷⁷—prevent pregnancy primarily by delaying or inhibiting ovulation and inhibiting fertilization, but may at times inhibit implantation of a fertilized egg in the endometrium. However, women should also be informed that the best available evidence indicates that ECPs prevent pregnancy by mechanisms that do not involve interference with post-fertilization events.
ECPs do not cause abortion⁷⁸ or harm an established pregnancy. Pregnancy begins with implantation according to medical authorities such as the US FDA, the National Institutes of Health⁷⁹ and the American College of Obstetricians and Gynecologists (ACOG).⁸⁰
Ulipristal acetate (UPA). One study has demonstrated that UP can delay ovulation.⁸¹... Another study found that UPA altered the endometrium, but whether this change would inhibit implantation is unknown.⁸²
p. 122:
Progestin-only emergency contraceptive pills. Early treatment with ECPs containing only the progestin levonorgestrel has been shown to impair the ovulatory process and luteal function.^83–87
p. 123:
Combined emergency contraceptive pills. Several clinical studies have shown that combined ECPs containing ethinylestradiol and levonorgestrel can inhibit or delay ovulation.^107–110
^ "Emergency Contraception". acog.org. Retrieved 2020-06-18.
^ Trussell J (2019). "Chapter 10 Emergency Contraception". Contraceptive technology. Cleland, K; Schwarz, EB (21st ed.). New York: Ardent Media. pp. 329–356. ISBN 978-1732055605. OCLC 1048947218.

[Cle2014-1] Cite error: The named reference Cle2014 was invoked but never defined (see the help page).

[Cle2012-2] Cite error: The named reference Cle2012 was invoked but never defined (see the help page).

[Leung_2010-3] Leung VW, Levine M, Soon JA (February 2010). "Mechanisms of action of hormonal emergency contraceptives". Pharmacotherapy. 30 (2): 158–168. doi:10.1592/phco.30.2.158. PMID 20099990. S2CID 41337748.

[Trussell_2011-4] Trussell J, Schwarz EB (2011). "Emergency contraception". In Hatcher RA, Trussell J, Nelson AL, Cates W Jr, Kowal D, Policar MS (eds.). Contraceptive technology (20th revised ed.). New York: Ardent Media. pp. 113–145. ISBN 978-1-59708-004-0. ISSN 0091-9721. OCLC 781956734. p. 121:
Mechanism of action
Copper-releasing IUCs
When used as a regular or emergency method of contraception, copper-releasing IUCs act primarily to prevent fertilization. Emergency insertion of a copper IUC is significantly more effective than the use of ECPs, reducing the risk of pregnancy following unprotected intercourse by more than 99%.^2,3 This very high level of effectiveness implies that emergency insertion of a copper IUC must prevent some pregnancies after fertilization.
Emergency contraceptive pills
To make an informed choice, women must know that ECPs—like the birth control pill, patch, ring, shot, and implant,⁷⁶ and even like breastfeeding⁷⁷—prevent pregnancy primarily by delaying or inhibiting ovulation and inhibiting fertilization, but may at times inhibit implantation of a fertilized egg in the endometrium. However, women should also be informed that the best available evidence indicates that ECPs prevent pregnancy by mechanisms that do not involve interference with post-fertilization events.
ECPs do not cause abortion⁷⁸ or harm an established pregnancy. Pregnancy begins with implantation according to medical authorities such as the US FDA, the National Institutes of Health⁷⁹ and the American College of Obstetricians and Gynecologists (ACOG).⁸⁰
Ulipristal acetate (UPA). One study has demonstrated that UP can delay ovulation.⁸¹... Another study found that UPA altered the endometrium, but whether this change would inhibit implantation is unknown.⁸²
p. 122:
Progestin-only emergency contraceptive pills. Early treatment with ECPs containing only the progestin levonorgestrel has been shown to impair the ovulatory process and luteal function.^83–87
p. 123:
Combined emergency contraceptive pills. Several clinical studies have shown that combined ECPs containing ethinylestradiol and levonorgestrel can inhibit or delay ovulation.^107–110

[5] "Emergency Contraception". acog.org. Retrieved 2020-06-18.

[:1-6] Trussell J (2019). "Chapter 10 Emergency Contraception". Contraceptive technology. Cleland, K; Schwarz, EB (21st ed.). New York: Ardent Media. pp. 329–356. ISBN 978-1732055605. OCLC 1048947218.

[1]

[2]

[3]

[4]

[5]

[6]