SHORT COMMUNICATION Lack of correlation between first trimester maternal serum 25-hydroxyvitamin D levels and ultrasound measured crown- rump length and nuchal translucency Ana M. Ferna ´ndez-Alonso • Gabriel Fiol-Ruiz • Peter Chedraui • Faustino R. Pe ´rez-Lo ´pez Received: 24 May 2011 / Accepted: 15 August 2011 / Published online: 30 August 2011 Ó Springer-Verlag 2011 Abstract Background Vitamin D regulates the human genome and it is thought to influence the fetal growth and development, but its relation to early ultrasound fetal measures is still unknown. Objective To assess first trimester 25-hydroxyvitamin D [25(OH)D] maternal serum status and correlate with ultrasound crown-rump length (CRL) and nuchal translu- cency (NT) measurements. Method In this cross-sectional study, women with sin- gleton pregnancies undergoing the first trimester standard two-dimensional ultrasound scan for fetal anomalies were included: CRL (n = 498) and NT (n = 487). Concomi- tantly, maternal serum 25(OH)D levels were also measured. Results Median serum 25(OH)D levels for the entire sample (n = 498) was 27.4 ng/mL (interquartile range 20.9–32.7). Serum 25(OH)D was adequate (C30 ng/mL) in only 36.1% of gravids, whereas levels were found to be insufficient (20–29.99 ng/mL) in 41.2% and deficient ( \ 20 ng/mL) in 22.7%. No significant correlation was found between the serum 25(OH)D levels and the mea- sured ultrasound parameters. Conclusion First trimester 25(OH)D levels did not cor- relate to fetal ultrasound measurements. Keywords 25-Hydroxyvitamin D Á Crown-rump length Á Nuchal translucency thickness Á First trimester pregnancy Á Vitamin D Introduction Vitamin D regulates the human genome [1, 2]. Indeed, more than 2,000 vitamin D receptor binding sites have been detected [3]. In addition, non genomic effects are responsible for rapid cell changes [4]. Vitamin D seems to be involved in implantation and placental development, displaying also antiproliferative and immunomodulatory actions [5–7]. The human placenta has the enzymatic activity of 25-hydrox- yvitamin D 3 -1a-hydroxylase (CYP27B1) and the 1,25(OH) 2 D-24-hydroxylase (CYP24A1), mainly involved in 1,25-dihydroxyvitamin D [1,25(OH)2D] synthesis and metabolism [8]. Early in human pregnancy maternal 25-hydroxyvitamin D [25(OH)D] serum levels may up- and down-regulate many genes. These regulations may be altered in women displaying lower 25(OH)D levels [9]. Nevertheless, reports that correlate human vitamin D status with early fetal morphology are still lacking. The aim of this study was to assess in singleton pregnancies first trimester 25(OH)D maternal serum status and correlate with ultra- sound crown-rump length (CRL) and nuchal translucency (NT) measurements. A. M. Ferna ´ndez-Alonso (&) Á G. Fiol-Ruiz Departamento de Obstetricia y Ginecologı ´a, Hospital Torreca ´rdenas, Paraje Torreca ´rdenas s/n, 04009 Almeria, Spain e-mail: amfa257@yahoo.es P. Chedraui Hospital Gineco-Obste ´trico Enrique C. Sotomayor, Facultad de Ciencias Me ´dicas, Universidad Cato ´lica de Santiago de Guayaquil, Guayaquil, Ecuador F. R. Pe ´rez-Lo ´pez Departamento de Obstetricia y Ginecologı ´a, Hospital Clı ´nico de Zaragoza, Facultad de Medicina, Universidad de Zaragoza, Zaragoza, Spain 123 Arch Gynecol Obstet (2011) 284:1585–1588 DOI 10.1007/s00404-011-2071-y