Pandya P et al. – Inclusion of serum PLGF improves the performance of the first–trimester combined test in screening for trisomy–21.Methods
- In singleton pregnancies attending for routine care, serum PLGF, free β–hCG and PAPP–A were measured at 8+0–13+6 weeks’ gestation, and fetal NT was measured at 11+0–13+6 weeks.
- The population included 12,154 normal and 44 trisomy–21 pregnancies.
- Authors examined the effect of adding PLGF on the performance of screening by the combined test.
- In the trisomy–21 pregnancies the median multiple of the normal median PLGF, adjusted for gestational age, maternal weight, racial origin, smoking status and method of conception, was significantly reduced (0.6070, 95% CI 0.5543–0.6648), and this did not change significantly with gestational age.
- Adding PLGF to combined testing with a risk cut–off of 1 in 100 reduced the false positive rate from 2.7% (95% CI 2.5–3.0) to 2.6% (95% CI 2.4–2.8) and increased the detection rate from 85% (95% CI 75–93) to 88% (95% CI 78–95).