SIZE AT BIRTH AND BLOOD-PRESSURE - CROSS-SECTIONAL STUDY IN 8-11 YEAR-OLD CHILDREN

Objective: To identify which patterns of fetal growth, represented by different measurements of size at birth, are associated with increased blood pressure in children aged 8-11 years. Design and setting: Schoo l based, cross sectional survey conducted in 10 towns in England and W ales in 1994, Subjects: 3010 singleton children (response rate 75%) wi th physical measurements and information on birth weight from parental questionnaires. Hospital birth records were examined for 1573, Main o utcome measures: Systolic and diastolic blood pressure at age 8-11 yea rs. Results: In the whole group birth weight was inversely related to systolic pressure (regression coefficient -1.48 mm Hg/kg; 95% confiden ce interval -2.20 to -0.76) after adjustment for current body size. Th ere was no significant association between birth weight and diastolic pressure, The association with systolic pressure was much stronger in girls (-2.54 mm Hg/kg; -3.60 to -1.48) than in boys (-0,64 mm Hg/kg; - 1.58 to 0.30), with a significant difference between the sexes (P=0,00 6), Among the other neonatal measures, head circumference and placenta l weight were inversely associated with subsequent blood pressure in g irls, and placental ratio (placental weight:birth weight) was positive ly associated with blood pressure in boys, Neither ponderal index at b irth nor length:head circumference ratio was related to blood pressure in either sex. Conclusions: In these contemporary children the associ ation between birth weight and blood pressure was apparent only in gir ls. There was no evidence that measures of size at birth, which may be related to nutrition at critical periods of pregnancy (thinness at bi rth or shortness in relation to head circumference), are related to bl ood pressure in the offspring.