Ectopic pregnancy (risk with respect to diff contraception)

• Mirena coil 0.02 per 100 woman-years
  • overall rates lower than with no contraception. But if a woman becomes pregnant with IUS in situ, risk is about 1 in 20 so she should seek advice to exclude it (1)
• Copper coil 0.25 per 100 woman-years
  • overall rates lower than with no contraception. But if a woman becomes pregnant with IUD in situ, risk is about 1 in 20 so she should seek advice to exclude it (1)

Depo-Provera inhibits ovulation - therefore the risk of ectopic pregnancy is very small (2).

A study (n=963,964 followed up for 7.8m person-years) found use of any levonorgestrel IUS linked to significantly increased risk of ectopic pregnancy vs other hormonal contraceptives, with highest risk for 13.5-mg IUS, including when compared with other doses (3)

• adjusted absolute rate (per 10,000 person-years) of ectopic pregnancy was 2.4 with other hormonal contraceptives, 7.7 with 52-mg (difference, 5.3), 7.1 with 19.5-mg (difference, 4.8), and 15.7 with 13.5-mg levonorgestrel IUS (difference, 13.4)
• corresponding relative rate ratios were 3.4 (95% CI, 2.4-4.8), 4.1 (95% CI, 2.9-5.9), and 7.9 (95% CI, 6.3-10.1). Ectopic pregnancy rate for each levonorgestrel IUS dose also increased with duration of use

Reference:

1. NICE (October 2005). Long-acting reversible contraception
2. Drugs and Therapeutics Bulletin (1996); 34 (12): 93-5
3. Meaidi A et al.Ectopic Pregnancy Risk in Users of Levonorgestrel-Releasing Intrauterine Systems With 52, 19.5, and 13.5 mg of Hormone. JAMA. 2023;329(11):935–937. doi:10.1001/jama.2023.0380