Spiral Arterial Morphology in Relation to Hypertension in Pregnancy and Birth Weight by Placental Bed Biopsy: A Retrospective Analysis

Background: Physiological changes in spiral arteries i.e. remodeling occur upto myometrial segment of the vessels and these changes are important for growth of the fetus. However in hypertensive pregnancies and IUGR, these changes are often not seen and arteries remain non-dilated. The aims of the study were to assess the extent of spiral vessel dilatation in hypertensive pregnancies and IUGR cases. Methods: Placental bed biopsy were taken in cases who underwent caesarean section and gave consent for the study, during the study period. 50 cases were included. Morphology and diameters of spiral arteries were assessed by histopathological examination. Arteries who retained the non-pregnant morphology were considered non-dilated and those who showed features of remodeling were considered normal. 14 cases were excluded as no vessel was seen in biopsy specimen. T-test and Chi-square tests were used for analysis. Out of the included 36 cases, percentage of non-dilated vessels was significantly high in gestational hypertension and preeclampsia(p=0.0230) and also significantly high in IUGR cases, (p=0.0113),irrespective of hypertension. Also the percentage of non-dilated vessels was higher in nulliparous women, though not significant. Placental bed biopsy specimens have limitations because they only provide information about a small segment of the placental bed. It is possible that areas close to the nonbiopsy site may have a completely different degree of vascular transformation. Moreover the number of cases in this study is less. Conclusion: Absence of spiral arterial remodeling is a crucial factor in hypertension in pregnancy and low birth weight babies. And adequate research is needed in this aspect so that such knowledge can help us to prevent hypertension in pregnancy and IUGR.