Quality specifications for S-AFP and S-HCG-beta determinations for screening of fetal abnormalities

Maternal serum second trimester AFP and hCG in pregnancies with placenta previa

This study was undertaken to investigate the association between placenta previa and Down syndrome screening analytes-alpha-fetoprotein (AFP) and hCG-during the second trimester. Measurements of maternal serum AFP and hCG concentrations were retrospectively analysed in relation to placenta previa in a cohort of 46 consecutive singleton pregnancies affected by placenta previa from January 1993 through December 1997 at the University Hospital of Kuopio, Finland, and then compared with those in healthy singleton control pregnancies (N=9560) from the same clinic over the same period of time. Geometric means of maternal serum AFP and hCG concentrations in pregnancies with placenta previa were 1.13 and 0. 85 multiples of the median (MoM), respectively. The mean maternal age was higher in the subjects than in the controls (30.9 years compared with 28.8 years) (p<0.01). In relation to Down syndrome risk assessment, the pattern of the two markers together with maternal age indicated high risk as often in the study subjects as in the controls. Even though the maternal serum AFP and hCG differences were not statistically significant, they may be of some clinical importance, and further studies are needed to evaluate whether placental site should be taken into account in maternal serum screening.

The effects on fetal development of high alpha-fetoprotein and maternal smoking

OBJECTIVES

This study determined the risk of impaired fetal growth resulting from the interaction between maternal smoking during pregnancy and unexplained elevated concentrations of maternal serum alpha-fetoprotein (MSAFP).

METHODS

This observational study involved 123 pregnant smokers with unexplained second-trimester elevated concentrations of MSAFP, 827 smokers with normal levels, and 471 nonsmokers with raised levels.

RESULTS

By logistic regression, coincident smoking and elevated MSAFP levels were found to be associated with increases in the low basic risks of prematurity, small-for-gestational-age births, low birthweight, and need for neonatal care.

CONCLUSIONS

Maternal smoking has an adverse effect on fetal development in pregnancies with unexplained elevated MSAFP concentrations. Such pregnancies merit close surveillance.