CLINICAL QUESTION

What is the incidence of pregnancy with same-day-start contraception compared with usual care?

BOTTOM LINE

Same-day-start contraception, regardless of the timing with the menstrual cycle, was associated with low pregnancy rates—0.4% for all methods—compared with 0.1% for traditional start. The cohort study provides evidence to support an any time, any method approach to contraception. Same-day initiation of oral or vaginal hormonal contraceptive methods had the highest incidence of pregnancy within the first month (1%). (Level of Evidence = 2b)

SYNOPSIS

Traditionally, contraception is initiated within the first 7 days of the menstrual cycle. In this prospective cohort of 3,568 individuals seeking contraception, 72% (n = 2,575) initiated their method outside of the traditional 7-day window. The cohort included patients 18 to 45 years of age who were fluent in English or Spanish, reported their intention of pregnancy prevention for at least 1 year, had a working mobile phone, and had an income of less than 300% of the poverty level. The investigators excluded individuals who had abortion care in the previous 2 weeks. The participants who reported having unprotected or underprotected intercourse in the previous 5 days received emergency contraception. The available contraceptive methods were etonogestrel implants, copper intrauterine devices, levonorgestrel intrauterine devices, medroxyprogesterone injections, oral hormonal contraception (combined or progestin only), and vaginal combined hormonal contraception. The researchers obtained data about pregnancy through telephone follow-up at 1 month, 3 months, and 6 months, and via electronic medical records. The main outcome (pregnancy within the first 30 days) occurred in 11 same-day starters (0.4%; 95% CI, 0.2 to 0.7) compared with 1 in 993 traditional-start users (0.1%; 95% CI, 0.0 to 0.6). Analysis by contraceptive method showed that most pregnancies (9 out of 11) were in patients who used oral or vaginal hormonal contraception and occurred in a total of 1% (9 out of 890) of those patients. There were four pregnancies (2.3%) among the 174 participants who received emergency contraception due to unprotected or underprotected intercourse.

Study design: Cohort (prospective)

Funding source: Industry and government

Setting: Outpatient (primary care)

Reference: Torres E, Carter G, Gero A, et al. Frequency of same-day contraceptive initiation, recent unprotected intercourse, and pregnancy risk: a prospective cohort study of multiple contraceptive methods. Am J Obstet Gynecol. 2024;230(6):661.e1-661.e7.