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).
Progesterone showed no clear difference in miscarriage per clinical pregnancy compared with no treatment or placebo (route of progesterone administration) (low certainty).
The review found no eligible studies for this question.
It is very uncertain whether intramuscular (IM) progesterone changes adverse events  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.
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.
It is very uncertain whether aqueous subcutaneous (Sc) progesterone changes ongoing pregnancy rate compared with vaginal progesterone gel (very low certainty).
Progesterone may leads to higher clinical pregnancy per woman compared with no treatment or placebo (route of progesterone administration) (low certainty).
It is very uncertain whether aqueous subcutaneous (Sc) progesterone changes clinical pregnancy rate compared with vaginal progesterone gel (very low certainty).
The review found no eligible studies for this question.
It is very uncertain whether subcutaneous (Sc) gonadotropin‐releasing hormone (GnRH) agonist changes ongoing pregnancy rate compared with placebo/no treatment (very low certainty).
It is very uncertain whether subcutaneous (Sc) gonadotropin‐releasing hormone (GnRH) agonist changes miscarriage rate compared with placebo/no treatment (very low certainty).
It is very uncertain whether subcutaneous (Sc) gonadotropin‐releasing hormone (GnRH) agonist changes clinical pregnancy rate compared with placebo/no treatment (very low certainty).