title: Ultrasound and endocrinological markers of first trimester placentation and subsequent fetal size.
abstract: BACKGROUND
  To study the relationship between 2-dimensional placental ultrasound measurements and maternal serum (MS) levels of biomarkers of placentation and in pregnancies presenting with an isolated abnormally high or low birthweight at term, without evidence of placental insufficiency.
  
  
  METHODS
  We performed a population based cohort study of 306 pregnancies delivered at term including 30 presenting with large-for-gestational age (LGA, birthweight > 90th centile) and 17 small-for-gestational age (SGA; birthweight < 10th centile). Antenatal measurements included placental thickness and 2D-volume and MS levels of pregnancy-associated plasma protein A (PAPP-A) and free-beta human chorionic gonadotrophin (fβhCG) at 11-13(+6) weeks of gestation and mid-trimester MS α-fetoprotein (AFP), unconjugated estriol (uE3) and inhibin A levels.
  
  
  RESULTS
  In the subgroup with a normal birthweight (10th-90th centile), there was a significant positive correlation between birthweight and the basal plate surface area (p < 0.001) and 2D placental volume (p < 0.01). In the LGA subgroup, MS PAPP-A was significantly (p < 0.05) higher than in normal controls and there was a significant (p < 0.01) positive correlation with birthweight. There was no significant difference for any of the ultrasound and biomarkers parameters between SGA and the normally grown controls.
  
  
  CONCLUSIONS
  In uncomplicated singleton pregnancies with a normal birthweight, 2D measurements of placentation are related with fetal size but are not related to subsequent excessive or slow fetal growth. LGA at birth is associated with increased MS PAPP-A at 11-14 weeks of gestation supporting the association between PAPP-A synthesis and early placental growth and development.
authors.affiliation: Research Department of Maternal Fetal Medicine, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK. Electronic address: a.david@ucl.ac.uk.
authors.forename: A L
authors.initials: AL
authors.lastname: David
authors.affiliation: Research Department of Maternal Fetal Medicine, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
authors.forename: E
authors.initials: E
authors.lastname: Jauniaux
mesh_terms: D015415:Biomarkers / Q000097:blood; D001724:Birth Weight; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D005260:Female; D047109:Fetal Development; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007265:Inhibins / Q000097:blood; D010929:Placentation; D011247:Pregnancy / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D011446:Prospective Studies; D012016:Reference Values; D016216:Ultrasonography, Prenatal
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D007265:Inhibins; D011266:Pregnancy-Associated Plasma Protein-A
keywords: Birth weight; Large for gestational age; Placental hormones; Placental volume; Small for gestational age