title: Serum placental growth factor in the three trimesters of pregnancy: effects of maternal characteristics and medical history.
abstract: OBJECTIVE
  To define the contribution of maternal variables which influence the measured level of maternal serum placental growth factor (PlGF) in screening for pregnancy complications.
  
  
  METHODS
  Maternal characteristics and medical history were recorded and serum levels of PlGF were measured in women with a singleton pregnancy attending for three routine hospital visits at 11 + 0 to 13 + 6, 19 + 0 to 24 + 6 and 30 + 0 to 34 + 6 or 35 + 0 to 37 + 6 weeks' gestation. For women delivering phenotypically normal live births or stillbirths ≥ 24 weeks' gestation, variables from maternal demographic characteristics and medical history important in the prediction of PlGF were determined from a linear mixed-effects multiple regression.
  
  
  RESULTS
  Serum levels of PlGF were measured in 38,002 cases in the first trimester, 10,281 in the second trimester and 12,392 in the third trimester. Significant independent contributions to serum PlGF were provided by gestational age, maternal age, weight and racial origin, cigarette smoking, diabetes mellitus, and gestational age at delivery and birth-weight Z-score of the neonate in the previous pregnancy. The machine used to measure serum PlGF was also found to have a significant effect. Allowing for other factors, the effect of maternal age on PlGF changed over the three trimesters, whereas other variables had constant effects over the three trimesters. Random-effects multiple regression analysis was used to define the contribution of maternal variables that influence the measured serum PlGF and express the values as multiples of the median (MoMs). The model was shown to provide an adequate fit of MoM values for all covariates, both in pregnancies that developed pre-eclampsia and in those without this complication.
  
  
  CONCLUSIONS
  A model was fitted to express the measured level of maternal serum PlGF across the three trimesters of pregnancy as MoMs, after adjusting for variables of maternal characteristics and medical history that affect this measurement.
authors: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors: A
authors: A
authors: Tsiakkas
authors: N
authors: N
authors: Duvdevani
authors: A
authors: A
authors: Wright
authors: D
authors: D
authors: Wright
authors: K H
authors: KH
authors: Nicolaides
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood* / Q000453:epidemiology; D006801:Humans; D007236:Infant, Small for Gestational Age; D008423:Maternal Age; D000072483:Placenta Growth Factor; D011237:Predictive Value of Tests; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000097:blood*; D011264:Pregnancy Trimesters; D011296:Prenatal Diagnosis; D011446:Prospective Studies; D018570:Risk Assessment; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D015415:Biomarkers; C000608036:PGF protein, human; D011257:Pregnancy Proteins; D000072483:Placenta Growth Factor
keywords: first-trimester screening; placental growth factor; pre-eclampsia; pyramid of pregnancy care; second-trimester screening; third-trimester screening; trisomy 21