Can this new method of emergency contraception provide more protection for women?

When an accident occurs, emergency contraception is an important way for women to protect themselves.

Wearing condoms correctly and taking birth control pills scientifically can reduce the risk of unwanted pregnancy from the beginning. However, accidents are inevitable - when unprotected intercourse occurs, male condoms break or slip, birth control pills are missed, or even sexual assault occurs, women may face risks and harm such as unwanted pregnancy and sexually transmitted diseases, and emergency contraception is an important remedy.

Since they were introduced to the market in the 1970s, oral emergency contraceptive pills and copper intrauterine devices have become the mainstays of emergency contraception. Now, women may have a new option. A new study in the authoritative medical journal The New England Journal of Medicine shows that progesterone-containing intrauterine devices, which are usually used for long-term contraception, also work well in emergency contraception.

New options for emergency contraception

Between 2016 and 2019, scientists at the University of Utah tracked more than 700 women aged 18 to 35 who had regular menstrual cycles and had unprotected sex within five days before their visit. After randomization, 317 women had a hormone-containing (levonorgestrel) intrauterine device implanted, and 321 had a copper intrauterine device implanted.

After 1 month, there were no unplanned pregnancies among women using copper IUDs, and one pregnancy among women using hormonal IUDs, with a contraceptive failure rate of 0.3%. Although the failure rate of the latter was slightly higher than that of the former, the difference was not statistically significant.

In other words, compared with the most effective emergency contraceptive method currently available - the copper intrauterine device, the emergency contraceptive effect of using a hormonal intrauterine device is not much different, which may become a new option for emergency contraception in the future.

Two types of intrauterine devices have their own advantages

In addition to contraceptive effectiveness, side effects are also an important consideration.

The copper IUD acts like a roadblock. Before the sperm and egg meet, some chemical reactions caused by copper affect the sperm motility and function, preventing fertilization. After the copper IUD is placed, women may experience varying degrees of prolonged menstruation, increased menstrual flow, or abnormal uterine bleeding between periods. This type of IUD itself can also cause abdominal pain or worsening dysmenorrhea, and is not suitable for women who are allergic to copper. In the above trial, 4.9% of women experienced side effects within 1 month after the copper IUD was placed.

A copper intrauterine device | Ceridwen / Wikimedia Commons

The drug ingredient of the hormonal IUD is levonorgestrel, a progestin that can inhibit ovulation. Due to the different mechanisms of action, the hormonal IUD can avoid some of the side effects of the copper IUD. Long-term use of hormonal IUDs can also help reduce the duration and amount of menstrual bleeding (especially perimenopause, menstrual irregularities caused by uterine fibroids), reduce abdominal pain or dysmenorrhea, and treat endometriosis and endometrial hyperplasia. In these aspects, compared with the copper IUD, the hormonal IUD is a better choice.

However, this type of IUD contains progesterone, which can also cause some side effects similar to birth control pills, such as headaches, dizziness, breast pain, back or abdominal pain, nausea, etc. One month after the placement of the hormone-containing IUD, the proportion of patients experiencing side effects was 5.2%. In addition, compared with the copper-containing IUD, which can be used for more than 10 years, the hormone-containing IUD can only be used for 3 to 5 years and is more expensive.

Intrauterine device or emergency contraception pill?

In addition to intrauterine devices, oral emergency contraceptive pills are also common emergency contraceptive methods. Both need to be used as soon as possible within 5 days after the event. If the fertilized egg has already implanted, it will not be effective in preventing pregnancy. Only by understanding the usage and pros and cons of various measures and considering your own needs can you choose the best solution.

Intrauterine devices are more effective than emergency contraceptive pills and can be used for long-term contraception and can be removed at any time when contraception is no longer needed.

However, the IUD is a foreign body to the human body, which may repeatedly irritate the uterine mucosa, causing inflammation, erosion or ulceration, and may also increase the risk of pelvic inflammatory disease or uterine perforation. It is also not suitable for patients with cervical cancer. IUDs are also not suitable for women who have unfortunately been sexually assaulted. Victims may face the risk of sexually transmitted infections such as chlamydia and gonorrhea, and the use of IUDs may further increase the risk of infection.

IUDs are not easily available and require inspection before use, which may make them difficult to become a popular emergency contraceptive method at present | Pixabay

Emergency contraceptive pills can only have a short-term effect, mainly through estrogen and progesterone to prevent or delay ovulation. At present, the emergency contraceptive pills recommended by the World Health Organization mainly include 3 types:

Combined oral contraceptives (ethinyl estradiol + levonorgestrel): Contains low doses of estrogen and progestin, with a failure rate of 2.7%.

Levonorgestrel: Progesterone reduces ovulation, with a failure rate of 1.2% to 2.4%. If emergency contraception fails, the development of the fetus is usually not affected.

Ulipristal acetate: It works by regulating progesterone receptors, with a failure rate of 1.2% to 1.9%. This drug is more effective than levonorgestrel within 3 to 5 days of sexual intercourse; however, it is not known whether Ulipristal acetate will affect the fetus after contraceptive failure.

Generally speaking, the later you take emergency contraceptive pills, the higher the failure rate. Moreover, emergency contraceptive pills cannot be used for long-term contraception. They only have a protective effect on sexual intercourse before taking the pills. After taking the pills, you still need to take reliable contraceptive measures such as condoms.

Even within the same menstrual cycle, oral emergency contraceptive pills can be used multiple times, and there is no such thing as "emergency contraceptive pills can only be taken three times a year." However, due to the effects of estrogen and progesterone, emergency contraceptive pills may have side effects such as nausea, vomiting, headache, abdominal pain, irregular vaginal bleeding, or changes in the menstrual cycle.

Emergency contraceptive pills are not a long-term method of contraception | Ceridwen / Wikimedia Commons

No matter which emergency contraceptive measure is used, there is still a risk of failure and may also bring corresponding side effects. After taking emergency contraceptive measures, if menstruation is delayed by more than 1 week than expected, or if symptoms such as lower abdominal pain and continuous irregular vaginal bleeding occur, you should go to the hospital for treatment in time.

Every year, there are about 85 million unplanned pregnancies worldwide, of which more than 50% end in artificial abortion; in 2014, there were as many as 9.62 million artificial abortions in my country. Whether it is artificial abortion or becoming a mother without any preparation, if there is a lack of emergency contraception, women will suffer great harm from unprotected sexual intercourse.

The World Health Organization's recommendations on emergency contraception state: "All women and girls at risk of unintended pregnancy have the right to access emergency contraception." New emergency contraceptive measures also mean that women will have more options for self-protection.

References

[1] David K. T, Alexandra G, Rebecca G. S, et al. Levonorgestrel vs. Copper Intrauterine Devices for Emergency Contraception. N Engl J Med 2021; 384:335-344.DOI: 10.1056/NEJMoa2022141

[2] Yuzpe AA, Thurlow HJ, Ramzy I, Leyshon JI. Post coital contraception--A pilot study. J Reprod Med. 1974 Aug;13(2):53-8. PMID: 4844513.

[3] Lippes J, Malik T, Tatum HJ. The postcoital copper-T. Adv Plan Parent. 1976;11(1):24-9. PMID: 976578.

[4] World Health Organization. Emergency contraception. Available from: https://www.who.int/news-room/fact-sheets/detail/emergency-contraception

[5] Emergency contraception. Practice Bulletin No. 152. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;126:e1–11. Available from: https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2015/09/emergency-contraception

[6] Cheng Linan, Di Wen, Ding Yan, et al. Chinese expert consensus on the clinical application of female contraceptive methods[J]. Chinese Journal of Obstetrics and Gynecology, 2018, 53(7):433-447.

Author: CHENG KT

Editor: Mai Mai