Ultrastructure of Hyrtl's Anastomosis of Pregnancy Induced Hypertensive Umbilical Arteries

Abstract

BACKGROUND The human umbilical arteries form an important component involved in the exchange of materials between the foetus and the mother. Hypertensive disorders in pregnancy are responsible for a significant amount of maternal and perinatal morbidity and mortality. It complicates about 6 - 20 % of all pregnancies. Although PIH (Pregnancy-induced hypertension) is one of the major causes of maternal death, especially in developing countries; its perinatal outcomes are also not so favourable. We wanted to study the ultrastructure of Hyrtl’s anastomosis between the normotensive and hypertensive placentas. METHODS A cross-sectional study was carried out to assess the variable anatomy in Hyrtl’s anastomosis and determine the alterations of the Hyrtl’s anastomosis in the case of pregnancy-induced hypertension from the year 2017-2018 at Sikkim Manipal Institute of Medical Sciences. For TEM (transmission electron microscopy) the portion of the Hyrtl’s anastomosis was carefully dissected out and processed. The study included women with pregnancy-induced hypertension if their arterial blood pressure with systolic as ≥ 140 mm Hg and diastolic ≥ 90 mm Hg measured on two or more occasions at least after the 20th week of gestation with or without oedema. Due to an inadequate number of cases essential hypertensive cases were excluded. RESULTS From the study conducted, transmission electron microscopy revealed a disrupted muscular layer in pregnancy-induced hypertension when compared to normal Hyrtl’s anastomosis. Thickening of the muscular layer was observed in the pregnancy-induced Hyrtl’s anastomosis. Statistical Analysis - Independent t-test was considered in the analysis for continuous among the ultrastructure of the Hyrtl’s anastomosis between the normotensive and hypertensive groups. P ≤ 0.05 was considered significant. SPSS 20.0 was used for data analysis. CONCLUSIONS The effect of hypertension brought about structural changes in the blood vessel which might probably have an effect on the fetoplacental circulation and therefore adversely affecting the foetal outcome. KEY WORDS Hyrtl’s Anastomosis, Pregnancy- Induced Hypertension