What do systematic reviews say?

LMWH prophylaxis vs UFH

It is very uncertain whether antenatal (± postnatal) prophylaxis: LMWH changes adverse effects sufficient to stop treatment compared with UFH (very low certainty).

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  RR 0.07 [0.01, 0.54]
  2 studies · 226 participants
  Very low

Peripartum/postnatal prophylaxis: UFH vs no treatment

The review found no eligible studies for this question.

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Peripartum/postnatal prophylaxis (caesarean): heparin (LMWH or UFH) vs no treatment/placebo

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 140 participants
  Very low

Peripartum/postnatal prophylaxis (caesarean): LMWH vs UFH

The review found no eligible studies for this question.

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Postnatal prophylaxis: LMWH vs no treatment/placebo

The review found no eligible studies for this question.

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Heparin prophylaxis vs no treatment/placebo

It is very uncertain whether antenatal (± postnatal) prophylaxis: heparin (LMWH or UFH) changes adverse effects sufficient to stop treatment compared with no treatment/placebo (very low certainty).

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  RR 0.49 [0.05, 5.31]
  1 study · 139 participants
  Very low

Magnesium sulphate vs placebo (outcomes

Magnesium sulphate probably leads to higher adverse effects severe enough to stop treatment** compared with placebo (outcomes (moderate certainty).

• Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus 2024 · Cochrane Headline outcomes only
  RR 3.21 [1.88, 5.48]
  3 studies · 4736 participants
  Moderate

Metformin vs placebo

Metformin leads to higher adverse effects associated with the treatment: diarrhoea compared with placebo (high certainty).

• Metformin for women who are overweight or obese during pregnancy for improving maternal and infant outcomes 2018 · Cochrane Headline outcomes only
  RR 2.34 [1.74, 3.14]
  2 studies · 797 participants
  High