Objectives: To ascertain whether angiogenic factors are altered in smokers at increased risk of preeclampsia (PE) according to uterine artery Doppler (UAD) assessment.
Methods: Uterine artery mean pulsatility index (PI), maternal placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1) serum levels were measured in 125 healthy pregnant women at 24 weeks of gestation. Smoking status was determined based on cotinine levels in maternal blood.
Results: Smokers had significantly higher PlGF concentration compared with nonsmokers [median PlGF levels: 575 (511) vs. 277 (259) pg/mL, respectively, p = 0.001]. The differences in PlGF levels were also observed between smokers and nonsmokers within the group of women with abnormal UAD and therefore at high risk of developing PE [median PlGF levels: 472 (434) vs. 235 (169) pg/mL, respectively, p = 0.0005]. In our patient cohort, 16 women developed PE (12.8%), of whom only 3 were smokers [odds ratios (ORs): 0.49; 95% confidence interval (CI) (0.13-1.84)]. In patients who finally developed intrauterine growth restriction, the PlGF/sFlt-1 ratio was significantly higher in the group of smokers compared with that of nonsmokers [0.39 (0.28) vs. 0.13 (0.21), respectively, p = 0.0311].
Conclusion: The effect of smoking in reducing the risk of PE may be due to the increase of PlGF and PlGF/sFlt-1 ratio in maternal blood, even among women with abnormal UAD.