Number of children and coronary heart disease risk factors in men and women from a British birth cohort

• Published in: BJOG : an international journal of obstetrics and gynaecology Vol. 114; no. 6; pp. 721 - 730
• Main Authors: Hardy, R, Lawlor, DA, Black, S, Wadsworth, MEJ, Kuh, D
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2007; Blackwell; Wiley Subscription Services, Inc
• Subjects: Biological and medical sciences; Body Mass Index; Cardiology. Vascular system; CHD risk factors; Children & youth; Cohort Studies; Coronary Disease - epidemiology; Coronary Disease - etiology; Coronary heart disease; epidemiology; Families & family life; Family Characteristics; Female; Gynecology. Andrology. Obstetrics; Health behavior; Heart; Humans; Male; Medical sciences; Men; Middle Aged; Parity; Pregnancy; Prospective Studies; Risk Factors; Socioeconomic Factors; United Kingdom - epidemiology; Women; United Kingdom; UK; Human; Cohort study; Gynecology; Risk factor; Sex; Cardiovascular disease; Birth; Coronary heart disease; Child; Epidemiology; Obstetrics
• ISSN: 1470-0328; 1471-0528
• DOI: 10.1111/j.1471-0528.2007.01324.x

Objective  To examine the association between number of children and coronary heart disease (CHD) risk factors in women and men. Design  Prospective cohort study. Setting  Britain. Sample  A total of 2977 individuals (51% women) from the Medical Research Council National Survey of Health and Development, a birth cohort study of individuals born in Britain in 1946 and followed up regularly throughout life. Main outcome measures  Blood pressure, body mass index (BMI), waist to hip ratio (WHR), total, high‐density lipoprotein and low‐density lipoprotein cholesterol and triglyceride levels, and glycated haemoglobin (HbA1C) measured at age of 53 years. Results  Number of children showed no consistent relationship with CHD risk factors at age 53 years in either men or women, and no obvious and consistent sex differences were observed. Mean BMI (95% CI) increased with increasing numbers of children (P = 0.01) in women from 27.4 kg/m2 (26.6–28.2) in those with one child to 28.6 kg/m2 (27.6–29.6) in those with four or more children. WHR and type II diabetes in women and HbA1C in men were the only other risk factors exhibiting a linearly increasing trend with increasing number of children. These associations were largely explained by adjustment for behavioural and lifestyle variables. Conclusion  Our findings suggest that any association between number of children and CHD risk factors is a result of lifestyle and behaviours associated with family life rather than being as result of the biological impact of pregnancy in women.