Growth In Utero and During Childhood Among Women Who Develop Coronary Heart Disease: Longitudinal Study

Abstract

Coronary heart disease (CHD) in Finnish men has been associated with low birth weight and more strongly with thinness at birth, as reflected by a low birth weight/length ratio. Mortality was highest in those who were thin when born but whose body weight caught up by age 7 years. The corresponding cohort of women born in the same hospital during the same years (1924–1933) now has been analyzed. Hazard ratios for hospital admission or death due to CHD were calculated for 3447 women. A total of 247 had been hospitalized for CHD, and 35 had died of it. Another 32 women had died without being admitted to a hospital. The annual death rate among women aged 45 to 64 years was 0.8 per 1000; the corresponding figure among men was 3.9 per 1000. Hazard ratios for CHD declined with increasing birth weight, although not to a significant degree. Adjusting for gestational age strengthened the association. The hazard ratio rose by approximately 10 percent for every centimeter decrease in length at birth (adjusted for length of gestation). Neither the ponderal index nor head circumference was a significant correlate of CHD risk in females. Hazard ratios did correlate with an increasing ratio of placental weight to gestation-adjusted birth weight. Women who developed CHD had grown less in height and weight from age 7 to 15 years. The relationship of shortness at birth and tallness in childhood to CHD was especially strong in women whose own mothers had been relatively tall. Differences between males and females in body size at birth seemed to be small, but differences in proportionate size were more marked. A short body length and high placental weight, the pattern predicting CHD in women, was much more prevalent in girls than in boys. Conversely, boys more often were thin at birth and had a large head circumference, and it was thinness at birth that predicted CHD in men. Sex-related differences in correlates of CHD may reflect differing rates of fetal growth at similar levels of maternal nutrition. Females may have less CHD because they grow more slowly in utero. Br Med J 1999;319:1403–1407