Pregnancy-specific beta 1-glycoproteins (PSGs) represent a large group (approximately 12-15) of proteins, related to members of the carcinoembryonic antigen family, that are abundant in placental tissue and in the sera of pregnant women. We describe the isolation and characterization of two additional PSG cDNAs, PSG9 and PSG10, whose transcripts are largely expressed in placental tissue and to a lesser extent in some other cell types, including myeloid cells differentiated to granulocytes. PSG9 and PSG10 are representatives of two distinct classes of PSG protein that have N-termini with or without the Arg-Gly-Asp motif implicated in adhesion. In addition to this distinction at the amino acid level, our analysis of several PSG cDNAs suggests that the transcription units encoding these proteins may be further distinguished in their 3' untranslated sequences, thus suggesting possibilities for transcriptional regulation of the two major protein classes.