The sebotrophic effect of pregnancy.

The sebum excretion rate (SER) in forehead skin was measured in late pregnancy and 8-20 weeks after delivery in 43 women. There was considerable individual variation but the mean SER during pregnancy was significantly higher than in a control group of non-pregnant women and it showed a large and significant decrease to the control level after delivery. This suggests that a powerful sebotrophic hormone is secreted during pregnancy. The mean SER during pregnancy in women with twins or triplets was no greater than the SER in women with a single foetus. This suggests that the sebotrophic factor of pregnancy is unlikely to be of placental origin, and is in keeping with the idea that the sebotrophic factor may come from the pituitary.