MOJ Women’s Health Research Article Open Access The placenta in pre-eclampsia: association of histology with umbilical artery Doppler velocimetry Abstract Volume 4 Issue 4 - 2017 Objectives: To study the association of umbilical artery Doppler velocimetry with 1 histological changes of the placenta in pre-eclampsia. GG Asanka Gunasena, DMCS Jayasundara,1Sujatha S Salgado,2 PS Method: This was an observational study, conducted at two tertiary care centers in Wijesinghe,3 Biyagama BRGDNK4 Sri Lanka between 2009 and 2010. A total of fifty placentae were studied; forty from 1Department of Obstetrics and Gynaecology, University of women with pre-eclampsia and ten from normotensive women with uncomplicated Colombo, Srilanka pregnancies. Twenty pre-eclamptic patients with abnormal umbilical artery Doppler 2Department of Anatomy, University of Kelaniya, Srilanka velocimetry were recruited in group 1. Group 2 included twenty gestational age- 3Department of Obstetrics and Gynaecology, University of matched, pre-eclamptic patients with normal umbilical artery Doppler velocimetry. Kelaniya, Srilanka Ultra sound scan for umbilical artery Doppler was carried out to obtain the pulsatility 4Department of Obstetrics and Gynaecology, Whipps Cross index (PI) and resistance index (RI) approximately 24hours prior to delivery. Five University Hospital, United Kingdom randomly selected, haematoxylin and eosin-stained sections from the maternal surface of each placenta were examined under high power (magnification 40) of Correspondence: GG Asanka Gunasena, Consultant, light microscopy. Hundred terminal villi in each slide were examined to identify Obstetrician and Gynaecologist, District Base Hospital, the presence of four histological features; syncytial knots, proliferative villous Rikillagaskada, Sri Lanka, Tel 0777704780, cytotrophoblast cells, thickening of sub-trophoblastic basement membrane, and Email [email protected] villous hypovascularity. Received: January 28, 2017 | Published: March 09, 2017 Results: All four histological features were present in a significantly higher proportion of placentae from pre-eclamptic patients (P<0.05) compared to normotensive placentae. The histological features of hypertensive placentae were not influenced by maternal age or parity but a statistically significant increase was noted with early onset hypertension (34weeks) compared to late onset hypertension (34weeks). In hypertensive placentae, all four histological features were present in comparatively higher proportions in Group 1 (abnormal umbilical artery Doppler velocimetry) compared to Group 2 (normal umbilical artery Doppler velocimetry). But statistical significance was observed only in villous cytotrophoblast proliferation (P=0.005), and villous hypovascularity (P=0.002). Conclusion: The placental histological changes are significantly increased in pre- eclampsia. Further deterioration of placental histology is associated with abnormal umbilical artery Doppler velocimetry. Keywords: pre-eclampsia; placental histology; umbilical artery doppler velocimetry Abbreviations: PI, pulsatility index; RI, resistance index; PE, long been recognized as the necessary component for the genesis pre eclampsia; FGR, fetal growth restriction; SLE, systemic lupus of preeclampsia. A common pathological feature of preeclampsia erythematosus; US, ultra sound; SGA, small for gestational age; POG, is the failure of the maternal spiral arteries supplying the placenta period of gestation to undergo the physiological adaptations of normal pregnancy to facilitate adequate placental perfusion.4 This theory of placental hypo- Introduction perfusion is supported by clinical, pathological and experimental findings.5 Hypertensive disorders are common during pregnancy requiring close antenatal care. Hypertension in pregnancy is defined as systolic The impaired placental perfusion precedes clinical manifestations blood pressure 140mmHg or diastolic blood pressure ≥90mmHg on of PE and it can be detected by Doppler ultrasound (US). Umbilical two occasions at least 4 hours apart after 20weeks of gestation in a artery Doppler reflects downstream placental vascular resistance, woman with a previously normal blood pressure. Pre-eclampsia (PE) correlated with the multisystem effects of placental deficiency. is traditionally defined as new hypertension presenting after 20weeks Recent meta analysis of randomized controlled trials suggests of gestation with significant proteinuria (≥300mg/dl in 24-hour urine that incorporation of umbilical artery Doppler waveform analysis collection).1 Worldwide, pre-eclampsia affects 5-10% of pregnancies into management protocols for high risk pregnancies significantly and it is a leading cause of maternal morbidity, mortality, fetal decreases perinatal mortality.6 Therefore, Doppler ultrasound growth restriction (FGR), and prematurity.2 The aetiology of PE is findings have become an increasingly common tool for evaluating still unknown, although an excessive maternal systemic inflammatory placental pathology in PE. A number of histopathological changes response and an imbalance between circulating angiogenic and of the hypertensive placentae have been described; namely placental anti-angiogenic factors have been described.3 The placenta has infarcts, increased syncytial knots, hypovascularity of the villi, Submit Manuscript | http://medcraveonline.com MOJ Womens Health. 2017;4(4):90‒94. 90 ©2017 Gunasena et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Copyright: The placenta in pre-eclampsia: association of histology with umbilical artery Doppler velocimetry ©2017 Gunasena et al. 91 increased cytotrophoblastic proliferation, thickening of the sub- villi had been encountered (Figure 1). Four histological features trophoblastic basement membrane, obliterated enlarged endothelial were analyzed in the terminal villi; syncytial knots, proliferative cells in the fetal capillaries and atherosis of the spiral arteries in the cytotrophoblast cells, sub-trophoblastic basement membrane placental bed. The volume of the intervillous space and the terminal thickening and villous hypovascularity. The proportions of terminal villi are also decreased in proportion to the degree of pre-eclampsia.7,8 villi containing each of the four histological characteristics were In this study, we assessed the histological features of the placentae calculated for each placenta. Syncytial knots in more than 30% of in pre-eclampsia and evaluated the correlation between histological villi,12 proliferative villous cytotrophoblast cells in more than 10% of changes and umbilical artery Doppler velocimetry. villi,13 basement membrane thickening in more than 20% of terminal villi and villous hypovascularity in more than 30% of terminal villi14 Materials and methods were taken as abnormal histological findings. The birth weights of This was an observational study carried out in two tertiary care the babies were measured in both groups and were categorized as normal weight or small for gestational age (SGA). SGA was defined centers in Colombo, Sri Lanka for a period of one year from 2009 th 15 to 2010. Women with a singleton gestation with pre-eclampsia as birth weight below the 10 centile for the gestational age Results were invited to participate, if they had fulfilled the inclusion and were analyzed by relevant statistical formulae using SPSS-version17. exclusion criteria to enroll in the study. Hypertension in pregnancy Mann-Whitney U-test was applied to compare the histological features was defined as systolic BP ≥140mm Hg or diastolic BP ≥90mm Hg between normotensive and hypertensive placentae. The same test was on two occasions at least 4hours apart after 20weeks of gestation applied to analyze the histological features in relation to maternal age, parity, and gestational age at the onset of hypertension. The X test was in a woman with a previously normal blood pressure.9 Proteinuria 2 was assessed by urine dipstick method. A dipstick reading of +1 is used to analyze the association of histological features with umbilical considered as significant proteinuria where quantitative methods are artery Doppler velocimetry. Informed written consent was taken from not available.9 We excluded pregnant women with gestational or pre- the patients for collection of the placenta for histological examination. existing diabetes mellitus, connective tissue disorders (e.g. SLE), Ethical approval was taken from the Ethical Review Committee of thrombophilic disorders, multiple pregnancies, placental tumours, and Castle Street Hospital for Women, Colombo 08. Confidentiality of the placental abruption. The confidence interval was set at 95% (α=0.05) subjects was maintained throughout the study. and power of study at 80% (β=0.02) which gave the sample size of 37 by using the relevant formula. Based on a previous study, abnormal histological features were assumed to be present in 90% of placentae with abnormal umbilical artery Doppler and 60% of placentae with normal umbilical artery Doppler.10 Ultra sound scan for umbilical artery Doppler was carried out to obtain the pulsatility index (PI) and resistance index (RI) in consented mothers 24hours prior to induction of labour or caesarean section. The Doppler US was performed by trans-abdominal examination with a GE-LOGIQ 3 PRO: AY-15CUI convex transducer. Umbilical artery measurements were taken in a