I found out about this at my breastfeeding class, but it is a study by the Arnold School of Medicine at USC and they are looking at breastfeeding in relation to allergies, infections, and asthma. They said that they were looking for mothers in the Charleston and Columbia area, but I am in Aiken and they took me into the study.
Basically you provide a blood sample, 2 milk samples, and do a few phone interviews. In return, they provide a medical grade breast pump for a couple of months, some Wal-Mart gift cards, and an allergy test when your child is 1 year old.
I am attaching the website with the study information in case you are interested in finding out further information on it. It does not seem to matter how far along you are in your preganancy, they came and picked up my blood samples today and brought me my breast pump and I am 2 days from my due date.