First-trimester umbilical vein blood flow in pregnancies with low serum pregnancy-associated plasma protein-A levels: an early predictor of fetal growth restriction.
OBJECTIVE
To investigate umbilical vein blood flow (UVBF) during the first trimester in pregnancies with low serum pregnancy-associated plasma protein-A (PAPP-A) levels and to relate umbilical vein (UV) diameter, time-averaged maximum velocity (TAMXV) and UVBF values to the subsequent development of fetal intrauterine growth restriction (IUGR).


METHODS
UVBF assessment was performed at 11 + 0 to 13 + 6 weeks' gestation in 102 singleton pregnancies with PAPP-A concentrations of < 0.3 multiples of the median. UV diameter, UV-TAMXV and UVBF were calculated and analyzed in relation to pregnancy outcome.


RESULTS
Pregnancy outcomes were: 51 pregnancies with birth weight ≥ 10(th) centile (Group A), 30 pregnancies with birth weight < 10(th) centile with normal Doppler in the umbilical artery throughout gestation (Group B) and 21 pregnancies with birth weight < 10(th) centile and abnormal umbilical artery Doppler later in gestation (Group C). No differences were found in PAPP-A levels between groups. Group C fetuses exhibited significantly lower values of UV-TAMXV (z-score - 1.99 SDs, t = 8.527, P ≤ 0.0001) and UVBF (z-score - 0.97 SDs, t = 7.420, P ≤ 0.0001) in comparison with normal reference ranges, while no differences were found in Groups A or B.


CONCLUSIONS
Decreased UV-TAMXV and UVBF at 11 + 0 to 13 + 6 weeks' gestation identify fetuses at risk of developing IUGR among pregnancies with low levels of PAPP-A.
Fetal Medicine Center, Genoma, Italy. giuseppe.rizzo@uniroma2.it
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Rizzo
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Capponi
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Pietrolucci
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Capece
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Arduini
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity / Q000502:physiology*; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis / Q000378:metabolism*; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014471:Umbilical Veins / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055815:Young Adult
D015415:Biomarkers; D011266:Pregnancy-Associated Plasma Protein-A