Progesterone probably leads to lower miscarriage compared with placebo or no treatment (moderate certainty).
Progesterone showed no clear difference in preterm birth compared with placebo or no treatment (low certainty).
It is very uncertain whether progesterone changes congential abnormalities compared with placebo or no treatment (very low certainty).
It is very uncertain whether progesterone changes benzodiazepine discontinuation, end of intervention compared with placebo (very low certainty).
It is very uncertain whether progesterone changes live birth or ongoing pregnancy compared with placebo/no treatment (very low certainty).
Progesterone may leads to higher clinical pregnancy compared with placebo/no treatment (low certainty).
The review found no eligible studies for this question.
Progesterone showed no clear difference in live birth or ongoing pregnancy compared with hCG regimens (low certainty).
Progesterone showed no clear difference in clinical pregnancy compared with hCG regimens (moderate certainty).
Progesterone may leads to lower OHSS compared with hCG regimens (low certainty).
It is very uncertain whether 300 mg vaginal progesterone changes ongoing pregnancy rate compared with 600 mg vaginal progesterone (very low certainty).
It is very uncertain whether 300 mg vaginal progesterone changes multiple pregnancy rate compared with 600 mg vaginal progesterone (very low certainty).
The review found no eligible studies for this question.
It is very uncertain whether intramuscular (IM) progesterone changes ongoing pregnancy rate compared with vaginal progesterone (very low certainty).
It is very uncertain whether intramuscular (IM) progesterone changes miscarriage rate compared with vaginal progesterone (very low certainty).
It is very uncertain whether intramuscular (IM) progesterone changes clinical pregnancy rate compared with vaginal progesterone (very low certainty).