What do systematic reviews say?

Antibiotics vs placebo or no treatment

Any antibiotics leads to lower infected episiotomy/laceration (deep perineal wound infection № of… compared with placebo or no treatment (high certainty).

• Antibiotic prophylaxis for operative vaginal delivery 2020 · Cochrane Headline outcomes only
  RR 0.46 [0.31, 0.69]
  Studies not reported
  High

Labour induction vs expectant management

Labour induction showed no clear difference in perineal trauma (severe perineal tear) compared with expectant management (maternal outcomes) (low certainty).

• Induction of labour at or beyond 37 weeks' gestation 2020 · Cochrane Headline outcomes only
  RR 1.04 [0.85, 1.26]
  5 studies · 11589 participants
  Low

Probiotics vs placebo

• Probiotic treatment for women with gestational diabetes to improve maternal and infant health and well‐being 2020 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Immersion in water vs no immersion during second stage of labour

The review found no eligible studies for this question.

• Immersion in water during labour and birth 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Immersion in water vs no immersion during first stage of labour

Immersion in water showed no clear difference in perineal trauma (third‐ or fourth‐degree tears) compared with no immersion during first stage of labour (moderate certainty).

• Immersion in water during labour and birth 2018 · Cochrane Headline outcomes only
  RR 1.36 [0.85, 2.18]
  4 studies · 2341 participants
  Moderate

Selective vs routine episiotomy: all vaginal births where operative vaginal delivery was not anticipated

Selective may leads to lower severe perineal/vaginal trauma compared with routine episiotomy: all vaginal births where operative vaginal… (low certainty).

• Selective versus routine use of episiotomy for vaginal birth 2017 · Cochrane Headline outcomes only
  RR 0.7 [0.52, 0.94]
  8 studies · 5375 participants
  Low

Selective vs routine episiotomy: all vaginal births where operative vaginal delivery was not anticipated

Selective showed no clear difference in perineal infection compared with routine episiotomy: all vaginal births where operative vaginal… (low certainty).

• Selective versus routine use of episiotomy for vaginal birth 2017 · Cochrane Headline outcomes only
  RR 0.9 [0.45, 1.82]
  3 studies · 1467 participants
  Low

Any upright vs supine

Any upright showed no clear difference in trauma to the birth canal that required suturing: second degree… compared with supine position (low certainty).

• Position in the second stage of labour for women without epidural anaesthesia 2017 · Cochrane Headline outcomes only
  RR 1.2 [1, 1.44]
  18 studies · 6715 participants
  Low

Low‐GI dietary advice vs moderate‐ to high‐GI dietary advice (child outcomes)

• Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Dietary advice vs standard‐of‐care therapy

It is very uncertain whether dietary advice interventions changes perineal trauma (anal sphincter injury) compared with standard care (maternal outcomes) (very low certainty).

• Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus 2017 · Cochrane Headline outcomes only
  RR 0.83 [0.23, 3.08]
  1 study · 759 participants
  Very low

Primary care screening vs secondary care screening

• Screening for gestational diabetes mellitus based on different risk profiles and settings for improving maternal and… 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Universal screening vs risk‐factor screening

• Screening for gestational diabetes mellitus based on different risk profiles and settings for improving maternal and… 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Metformin vs insulin

• Oral anti‐diabetic agents for women with established diabetes/impaired glucose tolerance or previous gestational… 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Preconception care vs usual care

• Preconception care for diabetic women for improving maternal and infant health 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Spontaneous pushing vs directed pushing

Spontaneous pushing showed no clear difference in perineal laceration (3rd or 4th degree) compared with directed pushing (low certainty).

• Pushing/bearing down methods for the second stage of labour 2017 · Cochrane Headline outcomes only
  RR 0.87 [0.45, 1.66]
  1 study · 320 participants
  Low

Delayed pushing vs immediate pushing (all women with epidural)

Delayed pushing showed no clear difference in perineal laceration (3rd or 4th degree) compared with immediate pushing (all women with epidural) (moderate certainty).

• Pushing/bearing down methods for the second stage of labour 2017 · Cochrane Headline outcomes only
  RR 0.94 [0.78, 1.14]
  7 studies · 2775 participants
  Moderate

Summary of findings: Energy‐restricted diet vs no energy‐restricted diet (maternal outcomes)

The review found no eligible studies for this question.

• Different types of dietary advice for women with gestational diabetes mellitus 2017 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Summary of findings: Low‐moderate GI diet vs moderate‐high GI diet (maternal outcomes)

The review found no eligible studies for this question.

• Different types of dietary advice for women with gestational diabetes mellitus 2017 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Adverse event outcomes for dietary combined with physical activity interventions vs standard‐of‐care therapy

Combined diet and exercise interventions showed no clear difference in perineal trauma compared with standard care (mother) (moderate certainty).

• Combined diet and exercise interventions for preventing gestational diabetes mellitus 2017 · Cochrane Headline outcomes only
  RR 1.27 [0.78, 2.05]
  2 studies · 2733 participants
  Moderate

Self‐monitoring vs intermittent glucose monitoring

• Different methods and settings for glucose monitoring for gestational diabetes during pregnancy 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported