Association between maternal circulating 25 hydroxyvitamin D concentration and placental volume in the first trimester Çiğdem Yayla Abide 1 Meryem Kurek Eken2, Işıl Turan1, Enis Özkaya1, Oya Pekin1, Ateş Karateke1 1. Zeynep Kamil Maternity and Children Training and Research Hospital - Department of Obstetric and Gynecology-Istanbul 2. Adnan Menderes University - Department of Obstetric and Gynecology- Aydın

Introduction Placental dysfunction can often lead to obstetric complications and suboptimal fetal outcomes. Many intrinsic and extrinsic factors can affect placental size and function [1]. Vitamin D in pregnancy is not only important for calcium metabolism and development of the fetal skeletal system but also for the development and maintenance of the maternal fetal unit [2].

Low maternal 25-OH vitamin D levels can lead to several poor obstetric and neonatal outcomes. As a malplacentation disease, pre-eclampsia and fetal growth restriction have been associated with vitamin D deficiency in pregnancy [3, 4]. Three-dimensional ultrasonography (3D-USG) has an increasingly important role in modern obstetrics.

The aim of this study was to evaluate volumetric and echogenic alterations in the placenta in pregnant patients with vitamin D deficiency and those with normal levels using 3D ultrasonography with VOCAL software.

Material and Methods This prospective cross sectional study comprised 274 patients, divided into two groups according to the presence or absence of vitamin D deficiency (<20ng/ml deficient, n=153,>20 ng/ml not deficient, n= 121) in the first trimester of pregnancy. Placental volume and placental volumetric mean gray values were evaluated.

Results Placental volume was significiantly less in the vitamin D deficiency group (p=0.017) Volumetric mean gray value of the placenta was significantly higher in the vitamin D deficiency group (p= 0.003) Maternal serum PAPP-A (MoM) and f-β Hcg (MoM) were significiantly lower in the vitamin D deficiency group (p= 0.008, p=0.003, respectively).

Parameter Group 1 25OH D vit ≤ 20ng/mL (n=153) Group 2 25OH D vit>20ng/mL (n=121) P values Placental Volume (cm3) 73.70±4.1 75.35±3.0 0.017** Mean Grey Value 49.95±10.8 46.58±7.76 0.003* PAPP-A (MoM) 1.43±0.7 1.69±0.6 0.008** f-β Hcg (MoM) 1.56±0.66 1.74±0.62 0.003**

Discussion&Conclusions With the hypothesis that as vitamin D is important from the first stages of placentation,vitamin D deficiency in pregnancy would lead to changes in the placental configuration. The placental hormones β-hcg and PAPP-A were observed to be lower in the group with vitamin D deficiency. This indicates that placental growth and also hormonogenesis were negatively affected

There fore,the results of the current study indirectly indicate that placental configuration depends on vitamin D. In pregnancies with vitamin D deficiency, the primary problem can be considered to be a reduction in placental vascularisation, which could lead to a secondary development of loss of placental volume.

References Longtine MS, Nelson DM. Placental dysfunction and fetal programming: the importance of placental size, shape, histopathology and molecular composition. Semin Reprod Med 2011;29: 187–96 Liu NQ, Hewison M . Vitamin D, the placenta and pregnancy. Arch Biochem Biophys. 2012;1;5 23:37-47 3. Robinson CJ, Wagner CL, Hollis BW, JE Baatz JE, Johnson DD. Maternal vitamin D and fetal growth in early-onset severe preeclampsia. Am J Obstet Gynecol.2011; 204: 556.1-4 4. BodnarLM, Catov JM Zmuda JM Cooper ME, Parrott MS JM. Roberts JM, Marazita ML, Simhan HN.Maternal serum 25-hydroxyvitamin D concentrations are associated with small-for-gestational age births in white women. J Nutr. 2010; 140: 999–1006 5. Hoogland HJ, de Haan J, Martin CB Jr. Placental size during early pregnancy and fetal outcome: A preliminary report of a sequential ultrasonographic study. Am J Obstet Gynecol. 1980; 138: 441–43