GSTM1 and preeclampsia: However, the intervention group within this subgroup had 76% reduction in risk of developing HDP (RR = 0.24, 95% confidence interval [0.11-0.53], P < 0.001) compared to the control group.<h4>Conclusion</h4>Low-dose aspirin was associated with a smaller decline in Hb levels and lower HDP risk; consistent with a potential hematological benefit beyond preeclampsia prevention, although this represents an association rather than causation.