What do systematic reviews say?

300 mg vaginal progesterone vs vaginal progesterone

It is very uncertain whether 300 mg vaginal progesterone changes ongoing pregnancy rate compared with 600 mg vaginal progesterone (very low certainty).

• Luteal phase support for women trying to conceive by intrauterine insemination or sexual intercourse 2022 · Cochrane Headline outcomes only
  RR 1.58 [0.81, 3.09]
  1 study · 200 participants
  Very low

300 mg vaginal progesterone vs vaginal progesterone

It is very uncertain whether 300 mg vaginal progesterone changes multiple pregnancy rate compared with 600 mg vaginal progesterone (very low certainty).

• Luteal phase support for women trying to conceive by intrauterine insemination or sexual intercourse 2022 · Cochrane Headline outcomes only
  RR 0.5 [0.05, 5.43]
  1 study · 200 participants
  Very low

Vaginal progesterone vs GnRH agonist

It is very uncertain whether vaginal progesterone changes clinical pregnancy rate compared with gonadotropin‐releasing hormone (GnRH) agonist (very low certainty).

• Luteal phase support for women trying to conceive by intrauterine insemination or sexual intercourse 2022 · Cochrane Headline outcomes only
  RR 1 [0.51, 1.95]
  1 study · 242 participants
  Very low

Vaginal progesterone vs no treatment or placebo

Vaginal progesterone showed no clear difference in infant birthweight less than 2500 g compared with no treatment or placebo (moderate certainty).

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  RR 0.95 [0.84, 1.07]
  3 studies · 2640 participants
  Moderate

Vaginal progesterone vs no treatment or placebo

Vaginal progesterone showed no clear difference in preterm birth less than 37 weeks compared with no treatment or placebo (moderate certainty).

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  RR 0.97 [0.89, 1.06]
  6 studies · 1597 participants
  Moderate

Vaginal progesterone vs no treatment or placebo

Vaginal progesterone showed no clear difference in preterm birth less than 28 weeks compared with no treatment or placebo (low certainty).

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  RR 1.53 [0.79, 2.97]
  3 studies · 1345 participants
  Low

Vaginal progesterone vs no treatment or placebo

Vaginal progesterone showed no clear difference in perinatal death compared with no treatment or placebo (low certainty).

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  RR 1.23 [0.74, 2.06]
  3 studies · 2287 participants
  Low

Vaginal progesterone vs no treatment or placebo

Vaginal progesterone showed no clear difference in preterm birth less than 34 weeks compared with no treatment or placebo (low certainty).

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  RR 0.9 [0.66, 1.23]
  5 studies · 1503 participants
  Low

Vaginal progesterone vs no treatment or placebo

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported