Objective: To identify the level of amniotic fluid lactate (AFL), placental growth factor (PLGF), and vascular endothelial growth factor (VEGF) at second trimester amniocentesis, and to compare levels in normal pregnancies with pregnancies ending in a miscarriage, an intrauterine growth restricted fetus (IUGR) or decreased fetal movements.

Study design: A prospective cohort study. Amniotic fluid was consecutively collected at amniocentesis in 106 pregnancies. Fetal wellbeing at delivery was evaluated from medical files and compared with the levels of AFL, VEGF, and PLGF at the time of amniocentesis.

Results: The median level of AFL was 6.9 mmol/l, VEGF 0.088 pg/ml, and PLGF 0.208 pg/ml. The median levels of AFL in pregnancies ended in miscarriage were significantly higher (10.7 mmol/l) compared to those with a live new-born (6.9 mmol/L, p = .02). The levels of VEGF (p = .2) and PLGF (p = .7) were not affected. In pregnancies with an IUGR, the median level of AFL was higher compared to those with normal fetal growth (p = .003). No differences VEGF (p = .5), but significant lower PLGF were found in IUGR pregnancies (p = .03).

Conclusions: Pregnancies ending in a miscarriage or with IUGR had significantly higher median values of AFL but lower values of PLGF in the amniotic fluid at the time of second trimester amniocentesis compared to normal pregnancies.