The effects of exposing rats to cigarette smoke on milk production and growth of offspring.

OBJECTIVES To analyze the effects of exposure to cigarette smoke during gestation and lactation on the milk production of rats and on the weight gain and linear growth of their offspring. METHODS Three groups of female rats were studied during gestation and lactation: 15 rats were exposed to cigarette smoke and air flow, 18 rats were handled, i.e., exposed to compressed air flow, and 18 rats were used as controls. Newborn rats were measured and weighed every 5 days, from the first to the 15th day. Milk production was estimated by 1-hour milk extraction and weight gained by litters. RESULTS The offspring of rats exposed to cigarette smoke weighed less and were shorter at birth. During lactation, the offspring of rats exposed to smoke and also of rats that had merely been handled gained less weight than the control group. Milk production gauged by the 1-hour extraction method was reduced in the group exposed to smoke and, to a lesser extent, also in the group that had been handled. Milk production estimated according to the pups' weight gain was reduced equally in the groups exposed to smoke and merely handled, when compared to the control group. CONCLUSIONS Exposure to cigarette smoke compromised the birth weight and birth length, but during lactation, handling also compromised weight gain of offspring. Handling and, to a greater extent, exposure to tobacco, were prejudicial to milk production.