The Southampton Women's Survey (SWS) was established to assess the influence of factors operating before conception and during pregnancy on the health and development of the offspring. 12,583 non-pregnant young women were recruited and the subsequent offspring of 3158 of them are being followed-up. Few other longitudinal studies of children have data on the tempo of prenatal growth, and none in high-income countries has information recorded before pregnancy.
The objectives of the SWS are: (a) to characterise the influences of a mother's own fetal growth and of her dietary balance, body composition and endocrine profile before and during pregnancy on (i) the early trajectory of fetal growth; (ii) the maintenance of this growth trajectory in late gestation; and (iii) placental and fetal adaptive responses, (b) to examine how maternal and intrauterine influences interact with the offspring's genes and postnatal environment to determine: (i) weight gain and linear catch-up growth in infancy; (ii) the pathways of growth and development during childhood that lead to poor adult health (obesity, obstructive airways disease, cardiovascular disease, diabetes, and osteoporosis).
Between 1998 and 2002, 12,583 women aged 20 to 34 years were interviewed and their diet, body composition, physical activity levels, lifestyles and social circumstances were assessed. Blood, urine and mouthwash samples were collected for genetic and other analyses. Women who subsequently became pregnant were followed-up at 11, 19 and 34 weeks' gestation and fetal ultrasound scans were performed to obtain longitudinal measurements of fetal growth during pregnancy. Between 1998 and 2007, 3,158 women delivered a single live born infant. Biological samples were taken and anthropometric measurements of the baby were made within 48 hours of birth. In a sample of 1,000 children, dual-energy X-ray absorptiometry (DXA) was performed in the first two weeks of life.
The children were followed up at ages 6, 12, 24 and 36 months. A variety of assessments were made at the different follow-up interviews including breastfeeding, diet, anthropometry, and illnesses. At 24 months, the social circumstances of the family were assessed and, at 36 months, parenting, and emotional and behavioural issues were recorded. Subsequently, samples of the cohort have been seen at specific ages; at 4 years approximately 1,000 cohort participants; at 6-7 years approximately 2,000, and at 8-9 years approximately 1,000. At each time point from 4 years, body composition and bone indices were assessed using DXA; at 4 years, cognitive function was measured, at 6-7 years the focus was respiratory health and cognitive function, and at 8-9 years cardiovascular structure and function. Over 1000 child have been seen at age 12-13 years and the visits at 17-19 years of age have been piloted and are about to start with a focus on preparation for parenthood. Furthermore, plans are being developed to follow up the 12,583 women originally recruited to the SWS to assess the influence of their younger adult lifestyles, body composition and hormones on their transition through the menopause.
