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).
It is very uncertain whether vaginal progesterone changes clinical pregnancy rate compared with gonadotropin‐releasing hormone (GnRH) agonist (very low certainty).
Vaginal progesterone showed no clear difference in infant birthweight less than 2500 g compared with no treatment or placebo (moderate certainty).
Vaginal progesterone showed no clear difference in preterm birth less than 37 weeks compared with no treatment or placebo (moderate certainty).
Vaginal progesterone showed no clear difference in preterm birth less than 28 weeks compared with no treatment or placebo (low certainty).
Vaginal progesterone showed no clear difference in perinatal death compared with no treatment or placebo (low certainty).
Vaginal progesterone showed no clear difference in preterm birth less than 34 weeks compared with no treatment or placebo (low certainty).
The review found no eligible studies for this question.
It is very uncertain whether oral progesterone changes ongoing pregnancy rate compared with vaginal progesterone (very low certainty).
It is very uncertain whether oral progesterone changes miscarriage rate per clinical pregnancy compared with vaginal progesterone (very low certainty).
It is very uncertain whether oral progesterone changes clinical pregnancy rate compared with vaginal progesterone (very low certainty).
The review found no eligible studies for this question.
The review found no eligible studies for this question.
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).
The review found no eligible studies for this question.