What is a obesterican?

It seems there might be a typo in your question. If you're asking about "obstetrician," it refers to a medical doctor specializing in obstetrics, which is the branch of medicine focused on pregnancy, childbirth, and the postpartum period. Obstetricians provide care to expectant mothers, monitor fetal development, and manage complications during pregnancy and delivery. If "obesterican" refers to something else, please clarify for further assistance.