What do systematic reviews say?

Any antihypertensive drug vs no antihypertensive drugs/placebo

Any antihypertensive drug showed no clear difference in elective delivery (induction of labour + elective caesarean section) compared with no antihypertensive drugs/placebo (moderate certainty).

• Antihypertensive drug therapy for mild to moderate hypertension during pregnancy 2018 · Cochrane Headline outcomes only
  RR 0.93 [0.84, 1.04]
  4 studies · 710 participants
  Moderate

Intensity of glycaemic control for women with gestational diabetes mellitus ‐ strict glycaemic targets vs less‐tight glycaemic targets (maternal outcomes)

• Different intensities of glycaemic control for women with gestational diabetes mellitus 2023 · Cochrane Headline outcomes only
  0.98 [0.82, 1.17]
  3 studies · 1662 participants
  Moderate

Intermittent ausculation of fetal heart rate in labour for fetal well‐being ‐ Intensive Pinard vs routine Pinard (outcomes

Intermittent ausculation of fetal heart rate in labour for fetal… showed no clear difference in caesarean section for fetal distress and/or fetal acidosis compared with routine Pinard (outcomes (low certainty).

• Intermittent auscultation (IA) of fetal heart rate in labour for fetal well‐being 2017 · Cochrane Headline outcomes only
  RR 0.7 [0.35, 1.38]
  1 study · 625 participants
  Low

Intermittent ausculation of fetal heart rate in labour for fetal well‐being ‐ Intensive Pinard vs routine Pinard (outcomes

• Intermittent auscultation (IA) of fetal heart rate in labour for fetal well‐being 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Planned early birth vs expectant management

Planned early delivery showed no clear difference in caesarean section compared with expectant management (moderate certainty).

• Planned early delivery versus expectant management for hypertensive disorders from 34 weeks gestation to term 2017 · Cochrane Headline outcomes only
  RR 0.91 [0.78, 1.07]
  4 studies · 1728 participants
  Moderate

Calcium supplementation/fortification vs placebo (outcomes

Calcium supplementation showed no clear difference in caesarean section compared with placebo (maternal outcomes) commencing before or early (low certainty).

• Calcium supplementation commencing before or early in pregnancy, for preventing hypertensive disorders of pregnancy 2019 · Cochrane Headline outcomes only
  RR 1.11 [0.96, 1.28]
  1 study · 578 participants
  Low

Tight vs moderate glycaemic control (maternal outcomes)

It is very uncertain whether tight changes caesarean section compared with moderate glycaemic control (maternal outcomes) (very low certainty).

• Different intensities of glycaemic control for pregnant women with pre‐existing diabetes 2016 · Cochrane Headline outcomes only
  RR 1.21 [0.22, 6.5]
  1 study · 45 participants
  Very low

Very tight vs tight‐moderate glycaemic control (infant outcomes)

It is very uncertain whether very tight changes caesarean section compared with tight‐moderate glycaemic control (maternal outcomes) (very low certainty).

• Different intensities of glycaemic control for pregnant women with pre‐existing diabetes 2016 · Cochrane Headline outcomes only
  RR 0.92 [0.49, 1.73]
  1 study · 22 participants
  Very low

Tight‐moderate vs less‐tight glycaemic targets (maternal outcomes)

Tight‐moderate may leads to lower caesarean section compared with loose glycaemic control (maternal outcomes) (low certainty).

• Different intensities of glycaemic control for pregnant women with pre‐existing diabetes 2016 · Cochrane Headline outcomes only
  RR 0.28 [0.1, 0.78]
  1 study · 60 participants
  Low