The Preterm Prediction Study: the value of serum alkaline phosphatase, alpha-fetoprotein, plasma corticotropin-releasing hormone, and other serum markers for the prediction of spontaneous preterm birth.
OBJECTIVE
High levels of a number of analytes are found in maternal blood; alkaline phosphatase,alpha-fetoprotein, and corticotropin-releasing hormone have been associated with spontaneous preterm birth. We investigated the relationship between 8 potential blood markers and subsequent spontaneous preterm birth in asymptomatic pregnant women.


METHODS
We performed a nested case control study that involved 127 women who were enrolled in the preterm prediction study and who had a singleton spontaneous preterm birth at <35 weeks and 127 women who had a term birth and served as matched (age, parity, center) controls. Serum that was collected at 24 and 28 weeks was analyzed for alkaline phosphatase, alpha-fetoprotein, corticotropin-releasing hormone, and 5 other analytes.


RESULTS
Alkaline phosphatase, alpha-fetoprotein, and corticotropin-releasing hormone, but not other analytes, were significantly elevated in pregnancies that ended in spontaneous preterm birth. For alkaline phosphatase at 24 weeks, the odds ratio for spontaneous preterm birth at <32 weeks was 6.8 (range, 1.4-32.8) and for spontaneous preterm birth at <35 weeks 5.1 (range, 1.7-15.6). Similar results were found at 28 weeks. For alpha-fetoprotein at 24 weeks, the odds ratio for spontaneous preterm birth at <32 weeks was 8.3 (range,2.2-30.9) and for spontaneous preterm birth at <35 weeks was 3.5 (range, 1.8-6.7). The levels at 28 weeks were still predictive but less so than at 24 weeks. Corticotropin-releasing hormone, at 28 weeks but not at 24 weeks, was predictive for spontaneous preterm birth at <35 weeks, with an odds ratio 3.4 (range, 1.0-10.9).


CONCLUSIONS
Elevated alkaline phosphatase and alpha-fetoprotein are associated with subsequent spontaneous preterm birth in asymptomatic pregnant women at 24 and 28 weeks. Elevated corticotropin-releasing hormone levels at 28 weeks are associated with spontaneous preterm birth at <35 weeks.
Moawad
Atef H
AH
National Institute of Child Health and Human Development Maternal-Fetal Medicine Unit Network, USA.
Goldenberg
Robert L
RL
Mercer
Brian
B
Meis
Paul J
PJ
Iams
Jay D
JD
Das
Anita
A
Caritis
Steve N
SN
Miodovnik
Menachem
M
Menard
M Kathryn
MK
Thurnau
Gary R
GR
Dombrowski
Mitchell
M
Roberts
James M
JM
D000469:Alkaline Phosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D005260:Female; D005544:Forecasting; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007743:Labor, Obstetric; D011247:Pregnancy; D000509:alpha-Fetoproteins / Q000032:analysis*
D015415:Biomarkers; D000509:alpha-Fetoproteins; D003346:Corticotropin-Releasing Hormone; D000469:Alkaline Phosphatase