The differences of serum levels of sFlt-1, PlGF, and sFlt-1/PlGF ratio throughout daytime and nighttime in women with severe preeclampsia at 30-34 weeks of pregnancy: a pilot study

Preeclampsia is identifiable by an imbalance of angiogenic factors, which entails elevated levels of sFlt-1 and a reduction of PlGF levels. In addition to disruptions in circadian rhythms, preeclamptic individuals may exhibit daytime and nighttime alterations in sFlt-1, PlGF, and the sFlt-1/PlGF ratio. This study aims to assess the differences in daytime and nighttime concentrations of sFlt-1, PlGF, and the sFlt-1/PlGF ratio in severe preeclamptic women between 30 and 34 weeks of gestational age. This cross-sectional study was conducted at Dr. Soetomo Public Academic Hospital and Airlangga University Hospital in Surabaya, involving ten pregnant women at 30-34 weeks of gestation, all diagnosed with severe preeclampsia. Samples of blood were drawn in the morning at 08:00, followed by the evening at 20:00. The study found no significant differences in serum levels of sFlt-1 (5.99 ± 3.29 vs. 6.82 ± 4.09 pg/mL), PlGF (85.5 [37-312] vs. 72 [35-437] pg/mL), and the sFlt-1/PlGF ratio (48.5 [6-233] vs. 58.5 [3-345] pg/mL) between day and night (p > 0.05). The results suggest that the circadian rhythm does not notably influence the serum levels of anti-and proangiogenic substances in confirmed severe preeclampsia.