Occult pregnancy as a factor in unexplained infertility

Occult pregnancy is defined as a pregnancy that terminates so soon after blastocyst formation that there is no clinical suspicion of its occurrence. A series of seven patients with unexplained infertility were studied by means of a specific hCG assay. Two of these other wise randomly selected patients showed the presence of occult pregnancies, as evidenced by positive titers, whereas five did not in the one cycle studied. The significance of this finding is discussed. It is suggested that a search for occult pregnancy may eventually form part of a routine infertility investigation.