title: First trimester pregnancy-associated plasma protein-A and birth weight.
abstract: OBJECTIVE
  To evaluate first trimester pregnancy-associated plasma protein-A (PAPP-A) and birth weight percentile.
  
  
  METHODS
  Included were women who underwent first trimester prenatal screening through the California Prenatal Screening Program with expected dates of delivery between August 2009 and December 2010, linked birth certificate and hospital discharge records, known birth weight, and no chromosomal abnormality (n=134.105). PAPP-A results were reported as multiples of the median. The frequency of small or large for gestational age (SGA, ≤10%; LGA, ≥90%) versus appropriately grown for gestational age birth was examined by PAPP-A percentile. Patterns were studied by gestational age at delivery. Relative risks (RRs) and their 95% confidence intervals were adjusted for race/ethnicity.
  
  
  RESULTS
  Women with PAPP-A ≤10th percentile and an infant born after 32 weeks were increasingly more likely to have an SGA infant (adjRRs 1.5-4.6) as the PAPP-A percentile declined, and were increasingly less like to have an LGA infant born at term (adjRRs 0.5-0.7) compared to women with PAPP-A measurement >10th to <90th percentile. PAPP-A ≥90th percentile was protective for SGA among infants born after 32 weeks gestation (adjRRs 0.3-0.7) and was associated with LGA among infants born at term (adjRRs 1.2-8.2).
  
  
  CONCLUSIONS
  Women with PAPP-A ≤10th percentile are more likely to have an SGA infant at all gestational ages. PAPP-A ≥90th percentile is protective against SGA and is associated with an increased risk of LGA for infants born after 32 weeks gestation.
authors.affiliation: Genetic Disease Screening Program, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA 94804, United States; Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States. Electronic address: rebecca.baer@cdph.ca.gov.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Baer
authors.affiliation: Stanford University, Department of Obstetrics & Gynecology, 300 Pasteur Drive, Stanford, CA 94305, United States. Electronic address: dlyell@stanford.edu.
authors.forename: Deirdre J
authors.initials: DJ
authors.lastname: Lyell
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, United States. Electronic address: nortonm@obgyn.ucsf.edu.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Norton
authors.affiliation: Genetic Disease Screening Program, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA 94804, United States. Electronic address: Bob.Currier@cdph.ca.gov.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Currier
authors.affiliation: Genetic Disease Screening Program, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA 94804, United States; Department of Epidemiology and Biostatistics, University of California School of Medicine, 550 16th Street, San Francisco, CA 94158, United States. Electronic address: Laura.Jelliffe@cdph.ca.gov.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Jelliffe-Pawlowski
mesh_terms: D001724:Birth Weight / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000097:blood*; D008562:Membrane Glycoproteins; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D011296:Prenatal Diagnosis; D017472:Receptors, Interleukin-1
chemical_list: D008562:Membrane Glycoproteins; D017472:Receptors, Interleukin-1; C434984:TIRAP protein, human; D011266:Pregnancy-Associated Plasma Protein-A
keywords: Birth weight; Large for gestational age; PAPP-A; Preterm birth; Small for gestational age