Heredity for hypertension influences intra-uterine growth and the relation between fetal growth and adult blood pressure.

Objective: To study whether heredity for hypertension influences intra-uterine growth and the relationship between fetal growth and adult blood pressure.
Design: Five-year prospective follow-up study with retrospective collection of data on size at birth and gestational age from obstetric records.
Setting: Centre of preventive medicine in Malmo, Sweden.
Subjects: Thirty normotensive men with and 27 without heredity for hypertension were investigated in 1990, and the majority (n = 28 and n = 20, respectively) in 1995 also.
Main Outcome Measures: Two measures of intra-uterine growth were compared between the groups and related to adult systolic blood pressure: the birth weight deviation from the expected birth weight based on ultrasonically derived intra-uterine growth curves, and the degree of thinness at birth (ponderal index = weight/length3).
Results: The birth weight deviation in men with heredity for hypertension differed significantly from that in men without such heredity (%) (-6.9+/-12.0 versus +7.3+/-18.4; P = 0.002). Ponderal index was somewhat lower in the men with than in those without heredity for hypertension, but the difference did not reach statistical significance (kg/m3) (25.9+/-2.6 versus 27.0+/-2.2; P = 0.08). In the group with heredity for hypertension, systolic blood pressure correlated inversely with ponderal index both in 1990 (r = -0.44; P = 0.01) and 1995 (r = -0.49; P = 0.009), and the 5-year increase in systolic blood pressure correlated inversely with the birth weight deviation (r = -0.38; P = 0.04). No such correlations were found in the group without heredity for hypertension.
Conclusion: Our results suggest that genetic factors contributing to the development of hypertension may influence intra-uterine growth.