What is the comparative effectiveness of various prophylactic treatments for preeclampsia and pregnancy-induced hypertension?
LMWH, exercise, calcium supplementation, and aspirin all reduce the risk of preeclampsia and PIH. The authors found no significant differences among the effectiveness of these strategies. Vitamin D supplementation was associated with reduced risk in the subgroup of studies conducted in Asia. However, the authors also stated that the certainty of evidence for most comparisons was low because of inconsistency and imprecision.
Plan de l'etude:
Meta-analysis (randomized controlled trials)
This paper describes an ambitious network meta-analysis of randomized controlled trials (RCTs) to simultaneously compare the results of 13 strategies to reduce the risk of preeclampsia and pregnancy-induced hypertension (PIH) among patients at increased risk. The authors included 130 trials with 112,916 participants. Risk factors included nulliparity, multifetal gestation, previous preeclampsia, chronic hypertension, type 1 and type 2 diabetes mellitus, thrombophilia, systemic lupus erythematosus, obesity, kidney disease, assisted reproductive technology, and maternal age 35 years or older. The vast majority of RCTs were of high quality. All trials were comparisons of 1 of the 13 strategies to placebo or no treatment. Publication bias was low when small studies (with less than 100 participants) were removed. Conclusions were similar with and without the small studies. The prophylactic strategies with significant effect to reduce the incidence of the primary composite outcome of preeclampsia and PIH, were low-molecular-weight heparin (LMWH), vitamin D supplementation, exercise, calcium supplementation, and aspirin. The authors conducted pairwise comparisons of the individual strategies and found no statistically significant differences between them. They conducted many subgroup analyses and found that the strategies that were consistently effective across all subgroups were aspirin and calcium supplementation. They found that high-dose rather than low-dose LMWH was effective, and that high-dose LMWH was more effective than aspirin in moderate risk patients. Both high- and low-dose aspirin were effective. Folic acid and vitamins C and E were all associated with an increased risk of PIH. The authors didn’t draw a conclusion about the effectiveness of selenium supplementation, citing a need for larger studies to assess risks and benefits.
Linda Speer, MD
Professor and Chair, Department of Family Medicine
University of Toledo