First trimester maternal serum alpha-fetoprotein is not raised in pregnancies with open spina bifida

Abstract

Our results confirm that maternal serum biochemical markers in the first trimester are unable to distinguish cases in which the fetus has open spina bifida.

Spina bifida screening in the first trimester using ultrasound biparietal diameter measurement adjusted for crown‐rump length or abdominal circumference

“…In the UK Collaborative AFP Study, the detection rate for all spina bifida, including closed cases at 10 to 12 weeks gestation, was 21% (6/29) using a 97th percentile cut‐off . In three first trimester series combined, the average AFP level in a total of 64 OSB cases was 1.28 MoM, although in a series of 39 cases, the median level was only 0.92 MoM . First trimester maternal serum free β‐hCG levels in OSB have been reported to be reduced in two series, and a published model found that adding both AFP and free β‐hCG to BPD MoM based on CRL increased detection from 50% to 58% for a 5% false‐positive rate .…”

“…MoM. 16 First trimester maternal serum free β-hCG levels in OSB have been reported to be reduced in two series, 8,16 and a published model found that adding both AFP and free β-hCG to BPD MoM based on CRL increased detection from 50% to 58% for a 5% false-positive rate. 8 When screening for Down's syndrome in the first trimester, performance can be enhanced by the addition of maternal serum AFP, with or without PlGF.…”

Impact on spina bifida screening of shifting prenatal Down syndrome maternal serum screening from the second trimester to the first

“…Firsttrimester AFP was recently suggested as a potential marker, but with controversial results. [30][31][32] Future research should focus on first-trimester biochemical markers.…”

Laboratory options for risk assessment of pregnancy pathologies

“…A further study of 44 cases of open spina bifida found a small but significant increase in maternal serum AFP in addition to a small but significant decrease in free β-hCG (Bernard et al 2013). On the basis of the study of Bernard and the results of study of Spencer (Spencer et al 2014) in conjunction with studies published in 1993 (Aitken et al 1993), one cannot confirm the value of first-trimester maternal serum AFP as a possible screening marker for open spina bifida in the first trimester. Spencer thinks, that one possible explanation for the differences between the few studies may be how cases identified by second trimester ultrasound are accurately classified as open spina bifida as opposed to closed lesions.…”

“…This in itself could lead to some heterogeneity amongst the cases. In the more recent publications (Bredaki et al 2012, Bernard et al 2013 there was no indication that diagnosis was confirmed by fetal exam, only that diagnosis occurred as a result of second trimester ultrasonography (Spencer et al 2014).…”