The fetal origins of disease hypothesis states that susceptibility to adulthood cardiovascular disease (CVD), non-insulin-dependent diabetes mellitus (NIDDM), and the insulin resistance syndrome (IRS) is programmed in utero and is a response to fetal under-nutrition. The hypothesis is also referred to as the thrifty phenotype hypothesis.

The insulin resistance syndrome refers to the clustering of certain disorders that increase one's risk of cardiovascular disease. Definitions usually include hypertension, dyslipidemia , and type 2 diabetes or impaired glucose tolerance. The syndrome has a variety of names in the literature: syndrome X, the insulin resistance syndrome (IRS), the metabolic syndrome, atherothrombogenic syndrome, and the deadly quartet.

While fetal programming for other adulthood disease outcomes have been examined, this lecture will focus on CVD, NIDDM, and IRS.