Maternal serum placental alkaline phosphatase level and risk for preterm delivery.
OBJECTIVE
The purpose of this study was to determine whether elevated midtrimester serum placental alkaline phosphatase levels are predictive of preterm delivery.


METHODS
By use of banked serum specimens from a sample of women who had received maternal serum alpha-fetoprotein screening, placental alkaline phosphatase values for multiples of the median were obtained from 270 mothers who had experienced a preterm delivery and from 1598 mothers of term, appropriate-for-gestational-age infants. Specimens were analyzed for placental alkaline phosphatase by means of a monoclonal antibody enzyme-linked immunosorbent assay. Logistic regression was used to determine whether placental alkaline phosphatase was associated with preterm birth, while potential confounders were controlled for.


RESULTS
Women with placental alkaline phosphatase levels > or = 2.0 multiples of the median were significantly more likely to be delivered of a preterm infant in the current pregnancy compared with women with levels < 2.0 multiples of the median (odds ratio 2.9, 95% confidence interval 2.1 to 3.9). The likelihood of preterm birth increased significantly with higher multiples of the median (p < 0.001).


CONCLUSIONS
Women with elevated placental alkaline phosphatase levels are at increased risk for preterm delivery. Additional studies are needed to evaluate the clinical utility of placental alkaline phosphatase testing as a means of identifying mothers at risk for preterm birth.
Meyer
R E
RE
Department of Epidemiology and Biostatistics, University of South Carolina School of Public Health, Columbia 29203, USA.
Thompson
S J
SJ
Addy
C L
CL
Garrison
C Z
CZ
Best
R G
RG
D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D007752:Obstetric Labor, Premature / Q000201:enzymology / Q000209:etiology*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012307:Risk Factors
D058851:GPI-Linked Proteins; D007527:Isoenzymes; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental