Is progesterone after IVF transfer safe during pregnancy?

What does the evidence say about progesterone after IVF transfer during pregnancy?

1. The ESHRE ovarian-stimulation guideline updated in 2025 and published in 2026 recommends progesterone for luteal support after IVF/ICSI and continuation at least until the pregnancy test. This is a minimum within its stimulation-cycle scope, not a universal stop instruction. 1
2. A Cochrane review found evidence supporting luteal-phase support in assisted reproduction, but comparisons involved varied medicines, routes, protocols, and evidence quality. Results do not establish one formulation as best for every transfer. 2
3. A meta-analysis of seven randomized trials in fresh IVF compared shorter with extended progesterone. The three studies reporting live birth found no statistically significant difference, but uncertainty remained and the findings do not apply automatically to programmed frozen transfers. 3
4. A review of luteal support describes substantial variation in practice, including duration after a positive test. Differences between protocols help explain why another patient’s stop week cannot determine your own prescription. 4
5. The ESHRE guideline recognizes several non-oral progesterone routes. Dose schedules differ by product and route, so an injection, vaginal capsule, gel, or suppository is not interchangeable milligram for milligram. 1

Is progesterone after IVF transfer safe in each trimester?

• First trimester. Before and after transfer, confirm the exact progesterone formulation, administration times, missed-dose instructions, pregnancy-test date, and whom to contact outside office hours. Fresh-transfer research does not establish a schedule for a programmed frozen transfer.
• Second trimester. If pregnancy continues, the fertility team sets the transition and stop plan. Persistent bleeding or pelvic pain needs assessment rather than assuming progesterone explains every symptom or guarantees a continuing pregnancy.
• Third trimester. Later pregnancy progesterone for a short cervix or another indication is a separate question. Do not continue an IVF prescription indefinitely or restart leftover medicine for contractions without obstetric advice.