IMALS

A method for monitoring pregnancy in a milk-producing domestic animal comprises determining the concentration of oestrogen conjugates, especially oestrone sulphate, contained in a sample comprising, or derived from, the milk of the animal and comparing this concentration with the average concentration of oestrogen conjugates in the milk of a non-pregnant similar animal of the same species. There is also provided a method for monitoring foetal well-being during the later stages of pregnancy which comprises, in addition, comparing the measured oestrogen conjugate concentration with that expected during a normal pregnancy.