To the question of the clinical predictive value of the sFlt-1:PlGF ratio is related to the placental dysfunction

Abstract

The objective: to evaluate the clinical and prognostic value and meaning of the ratio of the anti-angiogenic factor of soluble fms-like tyrosine kinase-1 (sFlt-1) to the angiogenic factor of the placental growth factor (PlGF) in the dynamics of pregnancy as markers of various variants of placental dysfunction. Materials and methods. A retrospective cohort study of 40 pregnant women, who were distributed by gestation term (up to 34 weeks and after 34 weeks) and the level of sFlt-1:PlGF ratio (<38 is low level, > 110 – high level) was performed. The statistical comparison of the sFlt-1:PlGF ratio with the development of hypertensive disorders during pregnancy and fetal growth retardation (FGR), as well as the duration of the period from research to childbirth was calculated. Results. Preeclampsia (PE) developed in 12 persons out of 40 pregnant women. The sFlt-1:PlGF ratio in the period till 27 weeks of pregnancy in groups of women with PE and without it does not differ with a statistically significant level (p=0.3). In other gestation terms the sFlt-1:PlGF ratio in women with and without placental dysfunction is statistically significant (p<0.05). The sFlt-1:PlGF ratio >38 increases the risk of PE more than 4 times (RR = 4.6) and is statistically significant in a period till 34 weeks [95 % CI: 1.4-14,9]. After 34 weeks of pregnancy the sFlt-1:PlGF ratio >110 has a higher sensitivity (Se=0.75).An analysis of the sFlt-1:PlGF ratio for the purpose of FGR predicting, both in combination with hypertensive disorders during pregnancy or without them, demonstrated its high importance during pregnancy up to 34 weeks (p=0.001). A strong reverse correlation (ƿ= -0.7) was found between the value of the sFlt-1:PlGF ratio and the number of days from the date of research till childbirth at the level of significance of 0.0001 in pregnant women up to 34 weeks. Conclusions. The predictive value of the conventional method of assessing the preeclampsia (PE) risk and the preventive efficiency of acetylsalicylic acid is low. In the absence of clinical manifestation of PE the determination of the sFlt-1:PlGF ratio for a predication till 27 weeks of pregnancy is not informative, so it is not recommended. If the sFlt-1:PlGF ratio is > 38 in the period till 34 weeks, the relative risk is 4.6 [95 % CI: 1.4–14.9]. If the level of the sFlt-1:PlGF ratio is high at first investigation there is no sense to repeat the research in dynamics. In the case of low the sFlt-1:PlGF ratio for a reasonable suspicion of PE development, repeated research can help make an adequate clinical decision. The determination of the sFlt-1:PlGF ratio for a predication or confirmation of fetal growth retardation till 34 weeks is clinically reasonable and informative. There is a strong reverse correlation between the sFlt-1:PlGF ratio and the number of days before the current birth.