MATERNAL-FETAL MEDICINE The relationship between the VEGF/sVEGFR-1 ratio and threatened abortion Ug ˘ur Keskin • Mustafa Ulubay • Murat Dede • Taner Ozgurtas • Yahya Kemal Koc ¸yig ˘it • Fevzi Nuri Aydin • Ali Ergu ¨n Received: 25 December 2013 / Accepted: 27 August 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract Purpose The aim of this study was to evaluate the levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor-1 (sVEGFR-1) and placenta growth factor (PlGF) and VEGF/SVEGFR-1 ratio in pregnant women with threatened abortion (TA) compared to uncomplicated pregnancies at the same gestational week. Methods Thirty-three pregnant women with TA and thirty-three pregnant women with uncomplicated preg- nancies were included in this case–control study. The level of VEGF, sVEGFR-1, and PIGF was analyzed by enzyme- linked immunosorbent assay (ELISA). The primary pur- pose of this study was to compare the VEGF, sVEGFR- 1, and PlGF levels and VEGF/sVEGFR-1 ratios in pregnant women with TA and pregnant women with uncomplicated pregnancies. The secondary purpose of this study was to evaluate the correlation between serum levels of these markers and gestational age. Results The serum levels of the sVEGFR-1 [0.60 (0.21–1.68) vs. 0.24 (0.09–0.57) ng/ml], VEGF [39.10 (6.57–163.56) vs. 5.24 (0.84–15.08) ng/ml] and VEGF/ SVEGFR-1 ratio [68.64 (6.45–550.48) vs 24.12 (2.63–72.63)] were significantly elevated in women with TA (respectively, p: 0.001, p: 0.001, p: 0.001). However, PlGF did not elevate in women with TA [20.80 (3.13–93.11) vs 20.16 (1.22–49.91) ng/ml] (p: 0.473). Conclusion These findings support the hypothesis that increased levels of the VEGF and sVEGFR-1 and VEGF/ SVEGFR-1 ratio may be associated with the pathogenesis of TA. Keywords Threatened abortion Á VEGF Á sVEGFR-1 Á PlGF Introduction Threatened abortion (TA) is the most common complica- tion of pregnancy (occurs up to 20 %) and 15–20 % end up with spontaneous abortion [1–4]. Although TA is not generally associated with serious morbidity or mortality, it may be associated with adverse outcomes later in preg- nancy such as spontaneous abortion, preterm birth, fetal growth restriction, and antepartum bleeding. TA described as the diagnostic criteria for spontaneous abortion have not been met, but vaginal bleeding has occurred and the cer- vical os is closed. Unlike other types of abortion, the pathophysiological mechanisms underlying TA are not fully understood. During fetal and placental development, one of the most important factors is angiogenesis. It is mainly regulated by pro-angiogenic and anti-angiogenic factors. Vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF) play major roles within this process, espe- cially in the stabilization of endothelial cells in mature blood vessels [5]. VEGF and PlGF are moderately pro- duced in normal pregnancies. So free VEGF and free PlGF may play a role in trophoblast proliferation and vascular formation. Soluble VEGF receptor-1 (otherwise known as U. Keskin (&) Á M. Ulubay Á M. Dede Á Y. K. Koc ¸yig ˘it Á A. Ergu ¨n Department of Obstetrics and Gynaecology, Gulhane Military Medical Academy and Medical School, 06018 Etlik/Ankara, Turkey e-mail: drugurkeskin@gmail.com T. Ozgurtas Á F. N. Aydin Department of Biochemistry, Gulhane Military Medical Academy and Medical School, Etlik/Ankara, Turkey 123 Arch Gynecol Obstet DOI 10.1007/s00404-014-3452-9