Placental vascularization alterations in hypertensive disorders complicating pregnancy (HDCP) and small for gestational age with HDCP using three-dimensional power doppler in a prospective case control study

Yuan et al. BMC Pregnancy and Childbirth (2015) 15:240 DOI 10.1186/s12884-015-0666-1 RESEARCH ARTICLE Open Access Placental vascularization alterations in hypertensive disorders complicating pregnancy (HDCP) and small for gestational age with HDCP using three-dimensional power doppler in a prospective case control study Ting Yuan, Ting Zhang and Zhen Han* Abstract Background: Hypertensive disorders complicating pregnancy (HDCP) continues to be a leading cause of maternal and neonatal mortality and morbidity. The clinical value of placental three-dimensional power Doppler (3DPD) in assessing HDCP requires further confirmation. The research was developed to assess changes of placental vascularity in HDCP using 3DPD and to investigate the placental vascularity in small for gestational age (SGA) compared with not-SGA in patients with HDCP. Methods: There were 126 normotensive and 128 hypertensive pregnant women included in this prospective case–control study from March 2011 to March 2013. Pregnant women underwent 3DPD. Vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were obtained. The placental 3DPD indices, umbilical artery systolic and diastolic ratio (S/D) and pregnancy outcomes were compared between the groups. Results: The placental VI and VFI were significantly lower in hypertensive women compared with normotensive women (P < 0.001 and P = 0.014, respectively), and these parameters were significantly reduced in severe preeclampsia (P < 0.001 and P = 0.003, respectively). A weak correlation was found between VI and umbilical artery S/D in HDCP group (r = -0.277, P = 0.001). In HDCP population, neonates who were postnatally diagnosed with SGA had lower VI (P = 0.041) and higher S/D (P < 0.001). Discussion: The placental vascularity indices decreased in hypertensive women and the reduction inplacental perfusion was consistent with the severity of the hypertensive disorder. The associations betweenplacental vascularization and umbilical artery impedance may be valuable for further researches and arerequired confirmation. The significant differences in the 3DPD placental vascularization between SGA andnot-SGA in hypertensive pregnancy population may show some clinical importance that we could use tobetter assess or predict the progression and adverse outcomes in the future. Although 3DPD quantificationhas been widely used in multiple publications, we have to acknowledge its limitations. Conclusions: The intraplacental vascularization was poor in HDCP, and especially in severe preeclampsia. Neonates with SGA had poor placental vascularization and higher umbilical artery S/D. Further studies should focus on the clinical assessment of placental 3DPD as well as a combination of placental 3DPD and other fetal Doppler indices to better predict the development and outcomes of preeclampsia. Keywords: Hypertensive disorders complicating pregnancy (HDCP), Placenta, Small for gestational age (SGA), Three-dimensional power Doppler (3DPD) * Correspondence: Department of Obstetrics and Gynecology, First Affiliated Hospital of Xi’an Jiaotong University College of Medicine, Shaanxi, China © 2015 Yuan et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Yuan et al. BMC Pregnancy and Childbirth (2015) 15:240 Background Hypertensive disorders complicating pregnancy (HDCP) continues to be a leading cause of maternal and neonatal mortality and morbidity [1]. The prevalence of HDCP is approximately 5.22 % of all pregnancies in China and 8–10 % worldwide [2, 3]. In recent years, important advances have been made in our understanding of the pathogenesis and pathophysiology of preeclampsia, but most of the factors that contribute to the disease remain unclear. Multiple tests and combination tests have been developed as screening methods for preeclampsia, including maternal serum biomarkers and Doppler parameters. To date, there is no effective screening test for HDCP [4–6]. HDCP is currently considered as a chronic placental disease. Placental dysfunction and hypo-perfusion play an important role in HDCP pathophysiology and are considered to be responsible for pathologic pregnancy outcomes, such as fetal growth restriction and perinatal loss [7–9]. Three-dimensional power Doppler (3DPD) has been a focal point of recent placental research; it is superior to 2D Doppler in several ways, including its ability to detect the secondary and tertiary stem vessels in the placenta and intraplacental vessel characteristics, such as the vessel density, branching, caliber changes and tortuosity, which can be shown using 3DPD [8, 10, 11]. Quantitative 3DPD analysis has been used to assess placental perfusion and vascularization indices, which potentially reflect both utero-placental and feto-placental blood perfusion [10]. Assessment of placental perfusion using 3DPD seems to be more helpful in understanding HDCP pathophysiology. However, the clinical value of placental 3DPD in assessing HDCP requires confirmation. The aim of our study was to compare changes in placental vascularity between HDCP and normotensive subjects using 3DPD, and to assess whether placental vascularity changes presenting in small for gestational age (SGA) compared with not-SGA in HDCP. Patients and methods Enrolment This was a prospective case–control study that was conducted at the First Affiliated Hospital of Xi’an Jiaotong University, ShaanXi, China, from March 2011 to March 2013. Women with HDCP were enrolled, and normotensive pregnant women were used as controls. HDCP and normotensive pregnant subjects were individually matched by maternal age ± 2 years and gestational week at examination ±2 weeks. The hypertensive group was further stratified into the following subgroups: (1) gestational hypertension (hypertension for the first time during pregnancy without proteinuria); (2) severe preeclampsia (diastolic Page 2 of 11 BP ≥110 mmHg, systolic BP ≥160 mmHg; proteinuria from none to positive; elevated serum creatinine and transaminase levels; obvious fetal growth restriction (FGR); multi-organ disturbances, such as headache, visual disturbance, upper abdominal pain, oliguria, convulsion, thrombocytopenia and pulmonary edema); (3) nonsevere preeclampsia (diastolic BP <110 mmHg, systolic BP <160 mmHg; proteinuria from none to positive; no multi-organ disturbances or only minimal serum transaminase elevation). Nonsevere preeclampsia includes “mild” and “moderate” (...truncated)