PAPP-A, free β-hCG, and early fetal growth identify two pathways leading to preterm delivery.
OBJECTIVE
To evaluate early fetal growth and the biomarkers, pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotrophin (β-hCG), in relation to preterm delivery.


METHODS
A cohort study of 9450 singleton pregnant women who attended the prenatal screening program at Aarhus University Hospital between January 2005 and December 2007, was conducted. PAPP-A and free β-hCG were measured in the first trimester. Early fetal growth was estimated by (GA(20)- GA(12))/Days(calendar), where GA(12) reflects the gestational age in days calculated from the crown-rump length at a 12-week scan, GA(20) reflects the gestational age in days calculated from the biparietal diameter at a 20-week scan, and Days(calendar) is the number of calendar days between the two scans.


RESULTS
Low PAPP-A and low free β-hCG were significantly associated with preterm delivery (<37 weeks). The association was even stronger when low PAPP-A and slow early fetal growth were combined, resulting in an adjusted odds ratio of 3.8 (95% CI, 1.6-8.7). Fast early fetal growth, but neither high PAPP-A nor high free β-hCG, was significantly associated with preterm delivery.


CONCLUSIONS
Two different biological pathways leading to spontaneous preterm delivery are suggested: fast early fetal growth and the combination of low PAPP-A and slow early fetal growth.
Kirkegaard
Ida
I
Perinatal Epidemiology Research Unit, Aarhus University Hospital, Skejby, Aarhus, Denmark. ida.kirkegaard@ki.au.dk
Uldbjerg
Niels
N
Petersen
Olav Bjørn
OB
Tørring
Niels
N
Henriksen
Tine Brink
TB
D000328:Adult; D015415:Biomarkers / Q000097:blood; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D015331:Cohort Studies; D018568:Crown-Rump Length; D003718:Denmark / Q000453:epidemiology; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D047928:Premature Birth / Q000097:blood* / Q000453:epidemiology
D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A