What do systematic reviews say?

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

Intramuscular (IM) progesterone vs no treatment or placebo

Intramuscular (IM) 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 1.45 [0.6, 3.51]
  6 studies · 3089 participants
  Low

Intramuscular (IM) progesterone vs no treatment or placebo

Intramuscular (IM) progesterone may leads to higher 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 1.54 [1.06, 2.26]
  2 studies · 399 participants
  Low

Intramuscular (IM) 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

Intramuscular (IM) progesterone vs no treatment or placebo

Intramuscular (IM) 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 0.99 [0.9, 1.08]
  5 studies · 4071 participants
  Moderate

Intramuscular (IM) progesterone vs no treatment or placebo

Intramuscular (IM) progesterone showed no clear difference in preterm birth less than 28 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 1.08 [0.75, 1.55]
  5 studies · 1920 participants
  Moderate

Intramuscular (IM) progesterone vs no treatment or placebo

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

• Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy 2019 · Cochrane Headline outcomes only
  RR 1.05 [0.98, 1.13]
  5 studies · 2010 participants
  High

GnRH‐a + medroxyprogesterone acetate vs GnRH‐a ± placebo

The review found no eligible studies for this question.

• Add‐back therapy with GnRH analogues for uterine fibroids 2015 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

GnRH‐a + medroxyprogesterone acetate vs GnRH‐a ± placebo

• Add‐back therapy with GnRH analogues for uterine fibroids 2015 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 16 participants
  Low

GnRH‐a + medroxyprogesterone acetate vs GnRH‐a ± placebo

• Add‐back therapy with GnRH analogues for uterine fibroids 2015 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 32 participants
  Low

GnRH‐a + medroxyprogesterone acetate vs GnRH‐a ± placebo

The review found no eligible studies for this question.

• Add‐back therapy with GnRH analogues for uterine fibroids 2015 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

GnRH‐a + medroxyprogesterone acetate vs GnRH‐a ± placebo

The review found no eligible studies for this question.

• Add‐back therapy with GnRH analogues for uterine fibroids 2015 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

GnRH‐a + medroxyprogesterone acetate vs GnRH‐a ± placebo

GnRH‐a + medroxyprogesterone acetate may leads to lower rate of vasomotor symptoms ‐ compared with gnRH‐a ± placebo (low certainty).

• Add‐back therapy with GnRH analogues for uterine fibroids 2015 · Cochrane Headline outcomes only
  RR 0.13 [0.02, 0.84]
  1 study · 16 participants
  Low