Reverse transcription and the polymerase chain reaction (PCR) were used to detect vascular endothelial growth factor (VEGF) mRNA in human placental tissue and cultured placental fibroblasts obtained during the first trimester of pregnancy. The primers for VEGF corresponded to areas in exon 4 and exon 8 of the VEGF gene. After one round of PCR three products, equivalent to VEGF121, VEGF165 and VEGF189, were detected within placental tissue and cultured placental fibroblasts. A further round of PCR revealed the presence of two more products equivalent to VEGF206 and VEGF145. Thus, in addition to the production of readily secreted forms of VEGF (VEGF121 and VEGF165), the placenta produces several transcripts expected to increase the growth factor pool of the extracellular matrix.