Empirical studies of the relationship between general cognitive ability and fertility span nearly a century. Reported effects generated through previous studies vary widely, and are believed to reflect differences in: 1) sample characteristics (e.g., gender, race, geographic region), and 2) methodological differences (e.g., different assessments of cognitive ability, range restriction, age of sample). The purpose of this study is to conduct a quantitative literature review using meta-analytic procedures. A thorough search identified 17 unique datasets that passed the inclusion criteria. The overall weighted effect was r = -.11. Analysis of variation in effect sizes due to methodological factors found significant differences due to age of sample (i.e., whether or not fertility was completed) with larger effects seen when fertility had not yet been completed. Further moderator analyses yielded stronger effects for females compared to males, and for Black and Hispanic groups compared to Whites. For studies conducted within the United States, the effect sizes were stronger among samples collected post Roe vs. Wade than those prior to the legalization of abortion indicating that the dysgenic trend may be stronger when women are afforded that option.