What do systematic reviews say?

Summary of findings table ‐ Progestogens vs placebo or no pretreatment

Progestogen showed no clear difference in pregnancy loss (Prog + Ant vs Ant) compared with placebo or no pretreatment (low certainty).

• Oral contraceptive pill, progestogen or oestrogen pretreatment for ovarian stimulation protocols for women undergoing… 2017 · Cochrane Headline outcomes only
  OR 0.36 [0.06, 2.09]
  1 study · 47 participants
  Low