PIP: Reply to the criticism in a recent paper of a study which concludes, based on the study by Martin Vessey, that women who postpone having their 1st child until after age 30 encounter only a "modest" increase in risk that they will not be able to conceive. Refutes arguments claiming flaws in the design of the study. Defended are the choice of population for the study, the extrapolation of fertility data from married, mostly parous women to nulliparous women in estimating infertility, as well as the method for calculation of age-specific 1-year conception rates. The author concludes that the modest estimate of actual levels of infertility arrived at earlier are a true representation of the actual fact.