Qualitative analysis
The sensitivity of LDH in predicting preeclampsia was reported in four articles that were particularly heterogeneous due to the quite heterogeneous optimal cut-off values that were evaluated; thus, precluding analysis of results. Specifically, Duan et al reported an area under the curve (AUC) that reached 0.899 and a sensitivity of 92.5% using a cut-off value of 183.5 U/L [20]. Similarly, Khalil observed that LDH could help differentiate severe preeclampsia from healthy controls as well as patients with proteinuria, gestational hypertension and mild preeclampsia using a cut-off value of 208 U/L (sensitivity 100%, AUC 71.2%) [21]. On the other hand, Fazal et al reported that the accuracy of LDH in detecting preeclampsia was limited (sensitivity 50% at an optimal cut-off of 525 U/L) [22]; however, their sample size was particularly small to establish definitive conclusions. Kasraeian et al used a cut-off of 336 U/L and observed that the specificity was also low (59%) [23].