What do systematic reviews say?

Metformin vs placebo or no treatment

It is very uncertain whether metformin changes clinical pregnancy rate per woman ‐ short protocol GnRH‐antagonist compared with placebo or no treatment (very low certainty).

• Metformin treatment before and during IVF or ICSI in women with polycystic ovary syndrome 2020 · Cochrane Headline outcomes only
  RR 1.38 [0.21, 9.14]
  2 studies · 177 participants
  Very low
• Metformin for ovulation induction (excluding gonadotrophins) in women with polycystic ovary syndrome 2019 · Cochrane Headline outcomes only
  OR 1.98 [1.47, 2.65]
  11 studies · 1213 participants
  Moderate

Metformin vs clomiphene

Metformin may leads to higher clinical pregnancy rate per womanaParticipants with BMI < 30 kg/m2… compared with clomiphene citrate (low certainty).

• Metformin for ovulation induction (excluding gonadotrophins) in women with polycystic ovary syndrome 2019 · Cochrane Headline outcomes only
  OR 1.56 [1.06, 2.29]
  6 studies · 530 participants
  Low
• Insulin‐sensitising drugs (metformin, rosiglitazone, pioglitazone, D‐chiro‐inositol) for women with polycystic ovary… 2017 · Cochrane Headline outcomes only
  OR 1.56 [1.05, 2.33]
  5 studies · 490 participants
  Very low

Metformin vs clomiphene

Metformin may leads to lower clinical pregnancy rate per woman aParticipants with BMI ≥ 30 kg/m2 compared with clomiphene citrate (low certainty).

• Metformin for ovulation induction (excluding gonadotrophins) in women with polycystic ovary syndrome 2019 · Cochrane Headline outcomes only
  OR 0.34 [0.21, 0.55]
  2 studies · 500 participants
  Low
• Insulin‐sensitising drugs (metformin, rosiglitazone, pioglitazone, D‐chiro‐inositol) for women with polycystic ovary… 2017 · Cochrane Headline outcomes only
  OR 0.34 [0.21, 0.55]
  2 studies · 500 participants
  Very low

Metformin combined with clomiphene citrate vs clomiphene

Metformin combined with clomiphene citrate probably leads to higher clinical pregnancy rate per woman compared with clomiphene citrate alone (moderate certainty).

• Metformin for ovulation induction (excluding gonadotrophins) in women with polycystic ovary syndrome 2019 · Cochrane Headline outcomes only
  OR 1.62 [1.32, 1.99]
  19 studies · 1790 participants
  Moderate
• Insulin‐sensitising drugs (metformin, rosiglitazone, pioglitazone, D‐chiro‐inositol) for women with polycystic ovary… 2017 · Cochrane Headline outcomes only
  OR 1.59 [1.27, 1.99]
  16 studies · 1529 participants
  Moderate

Alternative lipid emulsion (LE) vs S‐LE

• Lipid emulsions for parenterally fed preterm infants 2019 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 123 participants
  Low
• Alternative lipid emulsions versus pure soy oil based lipid emulsions for parenterally fed preterm infants 2015 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 497 participants
  Very low

Alternative lipid emulsion (LE) vs S‐LE

Alternative lipid emulsion (LE) showed no clear difference in any BPD – OS‐LE vs S‐LE (sensitivity analysis) compared with soybean oil‐based LE (S‐LE) (low certainty).

• Lipid emulsions for parenterally fed preterm infants 2019 · Cochrane Headline outcomes only
  RR 1.01 [0.57, 1.79]
  3 studies · 197 participants
  Low
• Alternative lipid emulsions versus pure soy oil based lipid emulsions for parenterally fed preterm infants 2015 · Cochrane Headline outcomes only
  RR 0.84 [0.63, 1.12]
  7 studies · 602 participants
  Very low

Prophylactic platelet transfusion at threshold of 10,000 vs higher transfusion threshold (20,000 or 30,000)

• Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for… 2015 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 255 participants
  Low
• Prophylactic platelet transfusion for prevention of bleeding in patients with haematological disorders after… 2012 · Cochrane Headline outcomes only
  RR 1.72 [1.33, 2.22]
  2 studies · 94205 participants
  Moderate

Prophylactic platelet transfusion at threshold of 10,000 vs higher transfusion threshold (20,000 or 30,000)

• Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for… 2015 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 333 participants
  Low
• Prophylactic platelet transfusion for prevention of bleeding in patients with haematological disorders after… 2012 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 333 participants
  Moderate

Short‐acting insulin analogues vs regular human insulin

Short‐acting insulin analogues showed no clear difference in all‐cause mortality (N) compared with regular human insulin (moderate certainty).

• Short‐acting insulin analogues versus regular human insulin for adult, non‐pregnant persons with type 2 diabetes… 2018 · Cochrane Headline outcomes only
  Peto OR 1.66 [0.41, 6.64]
  6 studies · 2519 participants
  Moderate

Short‐acting insulin analogues vs regular human insulin

• Short‐acting insulin analogues versus regular human insulin for adult, non‐pregnant persons with type 2 diabetes… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 2509 participants
  Low

Short‐acting insulin analogues vs regular human insulin

• Short‐acting insulin analogues versus regular human insulin for adult, non‐pregnant persons with type 2 diabetes… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  9 studies · 2608 participants
  Low

Short‐acting insulin analogues vs regular human insulin

• Short‐acting insulin analogues versus regular human insulin for adult, non‐pregnant persons with type 2 diabetes… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 2 participants
  Very low