title: First- and second-trimester maternal serum markers of pre-eclampsia in twin pregnancy.
abstract: OBJECTIVE
  To evaluate the distribution of first- and second-trimester maternal serum markers in twin pregnancy with and without pre-eclampsia.
  
  
  METHODS
  One-hundred and forty-four twin and 109 unaffected singleton pregnancies were recruited from the same institution. First- and second-trimester maternal blood samples were stored and measured retrospectively for serum placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotropin (β-hCG) and α-fetoprotein (AFP). All had measurement of first-trimester serum markers, and 167 (66%) had second-trimester tests. Values were expressed in multiples of the gestation-specific median (MoMs) in singletons, adjusted for maternal weight, as appropriate.
  
  
  RESULTS
  Pre-eclampsia was diagnosed in 12 (9.0%) twin pregnancies of 133 continuing beyond 22 weeks. In unaffected twin pregnancies, all serum markers were statistically significantly increased (P < 0.0001), consistent with a doubling of concentration. Among twin pregnancies, those with pre-eclampsia had a significantly reduced median PlGF compared with surviving unaffected twin pregnancies (0.96 MoM vs 1.46 MoM; P < 0.0002, two-tailed), whilst median PAPP-A, which is known to be reduced in affected singleton pregnancies, was increased (3.91 MoM vs 2.43 MoM; P < 0.0005, two-tailed). The levels of free β-hCG (P < 0.02) and AFP (P < 0.05) were also significantly raised, but to a lesser extent than was the level of PAPP-A. Using a logistic regression algorithm based on first- and second-trimester PlGF and PAPP-A, together with previously published uterine artery Doppler and mean arterial pressure measurements in the same series, the predicted pre-eclampsia detection rate was 65% for a 10% false-positive rate.
  
  
  CONCLUSIONS
  In twin pregnancy, the predicted detection rate of pre-eclampsia using first- and second-trimester maternal serum and biophysical markers is good. In contrast to singleton pregnancy, PAPP-A levels are raised in the first trimester of twin pregnancies destined to develop pre-eclampsia and therefore a different prediction algorithm is needed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
authors: Department of Obstetrics and Gynecology, Assaf Harofeh Medical Center, Zerifin, Israel, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: R
authors: R
authors: Svirsky
authors: Department of Obstetrics and Gynecology, Assaf Harofeh Medical Center, Zerifin, Israel, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: O
authors: O
authors: Levinsohn-Tavor
authors: Department of Obstetrics and Gynecology, Assaf Harofeh Medical Center, Zerifin, Israel, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: N
authors: N
authors: Feldman
authors: Department of Obstetrics and Gynecology, Assaf Harofeh Medical Center, Zerifin, Israel, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: E
authors: E
authors: Klog
authors: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: H
authors: H
authors: Cuckle
authors: Department of Obstetrics and Gynecology, Assaf Harofeh Medical Center, Zerifin, Israel, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: R
authors: R
authors: Maymon
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D005260:Female; D006801:Humans; D000072483:Placenta Growth Factor / Q000097:blood; D011225:Pre-Eclampsia / Q000175:diagnosis* / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood; D011262:Pregnancy Trimester, Second / Q000097:blood; D059285:Pregnancy, Twin / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; C000608036:PGF protein, human; D000509:alpha-Fetoproteins; D000072483:Placenta Growth Factor; D011266:Pregnancy-Associated Plasma Protein-A; C579283:PAPPA protein, human
keywords: early pregnancy; markers; maternal serum; pre-eclampsia; screening; twins