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  • Nathan Riley, MD

Obgyno Wino Podcast Episode 89 - Emergency Contraception

“It is the mark of an educated mind to be able to entertain a thought without accepting it."

- Aristotle


2019 Cabernet Franc from Chateau Laroque

PB #152, Published September 2015 (Reaffirmed 2018)


Five Pearls

1. Copper IUD is the most effective means of emergency contraception (although oral levonorgestrel and ulipristal acetate are also >98% effective)

2. Emergency contraception is not a reliable means of terminating a pregnancy.

3. Levonorgestrel is high effective up to 72 hrs after unprotected intercourse; ulipristal acetate and copper IUD up to 5 days after

4. Risks are minimal with any form of emergency contraception. Most serious risk of uterine perforation with copper IUD placement (1 in 1000)

5. Stop lying to women about the efficacy or requirements to obtain emergency contraception.


Emergency contraception (EC)?

- yeah...postcoital means for preventing pregnancy

- COCs were the first agents investigated, then came progestin-only regimens (e.g. Plan B), followed by IUDs

- most recently, selective progesterone receptor modulators (e.g. ulipristal acetate) were introduced, approved in 2010 by FDA

- of the available regimens, progestin-only oral regimens are most popular

- COCs no longer sold for this purpose (available evidence suggests efficacy is 70-90%)

- there are no contraindications to emergency contraception (per: US Medical Eligibility Criteria for Contraceptive Use, 2016)



What's the difference between this stuff and medical abortion?

- these methods haven't been found to be super effective in terminating a pregnancy that has already implanted

- even at high doses, COCs haven't been to be detrimental to established pregnancies or the embryo


Levonorgestrel ("Plan B")

- one dose of 1.5 mg of levonorgestrel --> available OTC without age restriction since 2013

- one-dose regimen is just as effective as the two-dose 0.75 mg regimen

- advertised as useful up to 72 hrs after unprotected sex (but still moderately effective up to 5 days after)

- inhibits/delays ovulation by delaying follicular development, esp if administered before the LH surge has taken place

- ~98% effective


Source: Merck Manual

Ulipristal acetate

- one-time 30 mg dose

- requires prescription

- works by blocking progesterone

- effective up to 120 hrs after unprotected sex

- inhibits/delays ovulation by delaying follicular development, EVEN if LH surge has already taken place

- in theory, may also make a pregnancy unsustainable if sperm-meets-egg by blocking the effects of progesterone produced by corpus luteum (but this hasn't really panned out in the literature...)

- ~98% effective


Cooper IUD ("Paragard")

- useful for at least 5 days after unprotected (maybe even longer!)

- levonorgestrel-releasing IUDs are under investigation for this purpose

- works by messing with the sperm and inflaming the endometrium, making it inhospitable for sperm

- most effective at nearly 100%


Adverse effects? - nausea and headache are most common AEs (20% and 10%, respectively)

- COC regimens cause more nausea/vomiting than levonorgestrel or ulipristal acetate

- irregular bleeding for a week or month after treatment is not uncommon; 15% in patients treated with levonorgestrel experience non-menstrual bleeding but the majority of women who receive EC can expect their normal menstruation within a week of expected bleed

- less common symptoms from the oral regimens include breast tenderness, abdominal pain, dizziness, or fatigue

- copper IUD placement carries unique risk of uterine perforation (1:1000); also associated with uterine cramping that will resolve soon after placement, and dysmenorrhea/heavier bleeding during cyclical bleeds

- EC doesn't increase risk for ectopic pregnancy (actually decreases absolute risk due to decreased risk of conception)


Not every woman is able to access EC

- RCTs that have demonstrated that women are fully capable of responsibly using this medication without increasing "risky sexual behavior" whatever that is

- some studies have even looked at the utility of providing women with EC at routine gyn visits

- unfortunately, in many parts of the world, these options aren't readily available

- education for young women is lacking

- OBGYNs and other women's healthcare providers are also poorly informed

- women who are sexually assaulted are not always offered EC in the ER (70% are offered)

- nor are women offered it even after consensual, unprotected sex (20% are offered)

- even though the 1.5-mg levonorgestrel regimen is available over-the-counter without a provider's prescription, in one study women posing as adolescents made calls to pharmacies inquiring about EC. The findings sort of say it all:


"First, ethical terms (personal or religious) were used to explain institutional pharmacy policies on EC availability. Second, there was confusion about the dispensing regulations regarding EC, given recent changes in United States policies. Third, pharmacy staff often introduced false barriers to EC access. In some cases, pharmacy staff used these barriers as justification for refusing to dispense EC; however, in other cases, pharmacy staff helped the adolescents overcome these false barriers. Finally, the degree of confidentiality in providing EC was unpredictable, with some pharmacies guaranteeing strict confidentiality and others explicitly telling adolescents, incorrectly, that their parents had to be informed."

Is a clinical examination required before prescription?

- Nah

- nor is clinical follow-up required afterwards (unless they develop abdominal pain or persistent vaginal bleeding)


Oral regimens are less effective in women with higher BMI

- despite this fact, oral regimens should not be withheld from women with obesity or who are overweight

- if your patient is overweight or living with obesity, emergency contraception is not a great long-term plan: IUDs are great in this population (efficacy is not affected by BMI)

- having said this, no dangers with repeated use of oral emergency contraception

When is it cool to initiate regular contraception?

- start using barrier contraception right away (unless an IUD was placed...in which case a barrier contraceptive method would only be required as protection against STDs)

- in theory, starting progestins may disrupt ulipristal efficacy, but this hasn't panned out in trials

- you can start any contraceptive 5 days after ulipristal acetate, but you should still use a barrier for 14 days (or until next menses or abstain altogether )

- no need to delay after levonorgestrel or COCs (use barrier contraception or abstain for 7 days)



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