What do systematic reviews say?

Cerclage vs no cerclage

Cerclage leads to lower preterm birth before 34 completed weeks compared with no cerclage (high certainty).

• Cervical stitch (cerclage) for preventing preterm birth in singleton pregnancy 2017 · Cochrane Headline outcomes only
  RR 0.77 [0.66, 0.89]
  9 studies · 2415 participants
  High

Main comparison (FFN knowledge vs no knowledge)

Main comparison (FFN knowledge showed no clear difference in preterm birth < 37 weeks compared with no knowledge) (low certainty).

• Fetal fibronectin testing for reducing the risk of preterm birth 2019 · Cochrane Headline outcomes only
  RR 0.72 [0.52, 1.01]
  5 studies · 434 participants
  Low

Main comparison (FFN knowledge vs no knowledge)

Main comparison (FFN knowledge showed no clear difference in preterm birth < 34 weeks compared with no knowledge) (low certainty).

• Fetal fibronectin testing for reducing the risk of preterm birth 2019 · Cochrane Headline outcomes only
  RR 1.09 [0.54, 2.18]
  4 studies · 357 participants
  Low

Main comparison (FFN knowledge vs no knowledge)

It is very uncertain whether main comparison (FFN knowledge changes preterm birth < 32 weeks compared with no knowledge) (very low certainty).

• Fetal fibronectin testing for reducing the risk of preterm birth 2019 · Cochrane Headline outcomes only
  RR 0.79 [0.16, 3.96]
  4 studies · 357 participants
  Very low

Intervention not reported

The intervention leads to lower preterm birth less than 34 weeks' gestation (high certainty).

• Home uterine monitoring for detecting preterm labour 2017 · Cochrane Headline outcomes only
  RR 0.78 [0.62, 0.99]
  3 studies · 1596 participants
  High

Intervention not reported

It is very uncertain whether the intervention changes preterm birth less than 37 weeks' gestation (very low certainty).

• Home uterine monitoring for detecting preterm labour 2017 · Cochrane Headline outcomes only
  RR 0.85 [0.72, 1.01]
  8 studies · 4834 participants
  Very low

Intervention not reported

It is very uncertain whether the intervention changes any preterm birth (birth < 37 weeks) (very low certainty).

• Care prior to and during subsequent pregnancies following stillbirth for improving outcomes 2018 · Cochrane Headline outcomes only
  RR 0.42 [0.04, 4.06]
  1 study · 24 participants
  Very low

Intervention not reported

The intervention showed no clear difference in any preterm birth (birth < 37 weeks) (low certainty).

• Care prior to and during subsequent pregnancies following stillbirth for improving outcomes 2018 · Cochrane Headline outcomes only
  RR 1.01 [0.58, 1.74]
  3 studies · 114 participants
  Low

SOF Immunological sealant vs usual care

It is very uncertain whether SOF Immunological sealant changes preterm birth less than 37 weeks' gestation compared with standard care (very low certainty).

• Sealing procedures for preterm prelabour rupture of membranes 2016 · Cochrane Headline outcomes only
  RR 0.48 [0.34, 0.68]
  1 study · 94 participants
  Very low

SOF Cervical adapter vs usual care

• Sealing procedures for preterm prelabour rupture of membranes 2016 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

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

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

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

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

Oral betamimetic vs placebo

Oral betamimetic showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo (low certainty).

• Prophylactic oral betamimetics for reducing preterm birth in women with a twin pregnancy 2015 · Cochrane Headline outcomes only
  RR 0.85 [0.65, 1.1]
  4 studies · 276 participants
  Low

Cervical cerclage in combination with antibiotics and tocolytics vs cervical cerclage

It is very uncertain whether cervical cerclage in combination with antibiotics and tocolytics changes preterm birth < 34 completed weeks of pregnancy compared with cervical cerclage alone (very low certainty).

• Cervical stitch (cerclage) in combination with other treatments for preventing spontaneous preterm birth in singleton… 2020 · Cochrane Headline outcomes only
  RR 0.78 [0.44, 1.4]
  1 study · 50 participants
  Very low

Intervention not reported

It is very uncertain whether the intervention changes preterm birth < 34 weeks (very low certainty).

• Cervical assessment by ultrasound for preventing preterm delivery 2019 · Cochrane Headline outcomes only
  RR 0.62 [0.3, 1.25]
  1 study · 125 participants
  Very low

Intervention not reported

It is very uncertain whether the intervention changes preterm birth < 37 weeks (very low certainty).

• Cervical assessment by ultrasound for preventing preterm delivery 2019 · Cochrane Headline outcomes only
  RR 0.59 [0.26, 1.32]
  2 studies · 242 participants
  Very low