What do systematic reviews say?

Low molecular weight heparin vs UFH

LMWH probably leads to lower incidence of recurrent VTE1 (end of compared with UFH (moderate certainty).

• Fixed dose subcutaneous low molecular weight heparins versus adjusted dose unfractionated heparin for the initial… 2017 · Cochrane Headline outcomes only
  OR 0.72 [0.59, 0.88]
  22 studies · 9489 participants
  Moderate