The MUSP is a birth cohort study with a focus on specific developmental paths and risk factors for conditions such as obesity, metabolic syndrome, diabetes, and mental health. The study included over 8,500 pregnant women at baseline who entered the study at their first clinic visit at the Mater Misericordiae Hospital in Queensland, Australia. Across 3 years from study inception in 1981, 6,703 mothers gave birth to a total of 7,223 live single babies. Mothers' ages ranged between 13 and 46 years old; the average age was 24 years. A total of 73% of mothers were married, around 12% were in de facto relationships, and 13% were single, divorced/separated, or widowed. Around 72% of mothers were born in Australia, nearly 10% in the United Kingdom, over 4% in New Zealand, nearly 3% in Southeast Asia, and another 8.5% in the Mediterranean, Southern Europe, Western Europe, Eastern Europe, Pacific Islands, and other parts of the world. Of all the children born, 52% were boys and 48% were girls.