Buprenorphine decreased organ mass in pups.

<p>Prenatal buprenorphine (0, 0.3, and 1 mg/kg/day) exposure was started from gestation day 7 and lasted for 14 days. After birth, the male and female pups were collected at postnatal day 21. At this time, the body mass and brain mass of dams (A) and pups (B) were weighed and the ratio of brain mass in body mass (%) was calculated. The body mass of dams was recorded prior to the start of experiments (beginning) and at the end of experiments (end). **p<0.01 vs. each vehicle group, n = 20 per group.