This paper studies the link between rising income uncertainty and household fertility patterns in an Aiyagari-Bewley-Huggett framework augmented to include fertility decisions and infertility risk. Building on Becker and Tomes (1976), I model fertility decisions as sequential, irreversible choices over the number of children, accompanied by parental choices of time and money invested toward improving children's quality. The calibrated model is used to quantify the contribution of earnings uncertainty to the changes in the key fertility indicators between steady states. I show that realistic increases in uninsurable earnings risk lead to a postponement in births by young households, and are associated with a decline in the total number of births. The linkage between earnings risk and fertility patterns highlights the important role that labor market conditions can play in determining both short-term cyclical fluctuations in fertility (such as those in the recent U.S. data) and longer-term demographic trends (such as persistently depressed fertility rates in Southern Europe where youth unemployment rates are high and unemployment spell are very persistent).