somatomammotropin

noun

so·​ma·​to·​mam·​mo·​tro·​pin ˌsō-mət-ə-ˌmam-ə-ˈtrōp-ᵊn, sə-ˌmat-ə- 

: any of several hormones (as growth hormone and prolactin) having lactogenic and somatotropic properties

especially : placental lactogen