First-trimester serum marker distribution in singleton pregnancies conceived with assisted reproduction.
OBJECTIVE
To evaluate marker distribution of free beta-human chorionic gonadotrophin (fbeta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in singleton pregnancies conceived by assisted reproduction techniques (ART).


METHODS
In vitro fertilization (IVF) (n = 203) and intracytoplasmic sperm injection (ICSI) (n = 192) cases from a database of 14 645 first-trimester combined tests (overall study group) were selected and matched to 1164 controls for gestational age at sample date and maternal age.


RESULTS
In the IVF group and ICSI group, lnPAPP-A was lower (IVF 6.74 vs 7.08; P = 0.0001; ICSI 6.59 vs 7.07; P = 0.0001) compared with the matched controls. Lnfbeta-hCG was lower in the IVF group (3.75 vs 3.90; P = 0.005) but not significantly different in the ICSI group (3.87 vs 3.93; P = 0.27). The computed correction factors for PAPP-A and fbeta-hCG were 1.42 and 1.17 for the IVF group and 1.56 and 1.05 for the ICSI group.The false-positive rate (FPR) in the IVF and ICSI group compared with the matched controls was higher (IVF 10.3% vs 8.6% and ICSI 10.9% vs 7.5%). In the overall age-biased [maternal age significantly lower compared with all ART and control groups] study group the FPR was 6.8%.


CONCLUSIONS
The increase in FPR in the ART groups can be explained by decreased PAPP-A values. Therefore, an adjustment in risk analysis for Down syndrome is suggested.
Engels
M A J
MA
Department of Obstetrics and Gynecology, VU University Medical Center, Amsterdam, The Netherlands. m.engels@vumc.nl
Kooij
M
M
Schats
R
R
Twisk
J W R
JW
Blankenstein
M A
MA
van Vugt
J M G
JM
D000328:Adult; D015415:Biomarkers / Q000097:blood; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy / Q000097:blood*; D011261:Pregnancy Trimester, First / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D012015:Reference Standards; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic
D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A