Objective: To examine the association between intrauterine growth restriction (IUGR) status at birth among full-term infants, exposure to substance use during pregnancy, and risk of hypertension at 6 years of age.
Design: Prospective evaluation of high-risk children.
Setting: Four centers of the National Institute of Child Health and Human Development Neonatal Research Network.
Participants: One thousand three hundred eighty-eight infants (600 cocaine exposed, 781 nonexposed, and 7 indeterminate, matched by gestational age, race, and sex), were enrolled at these sites. Nine hundred fifty children (415 exposed, 535 nonexposed) were followed up for 6 years. Intervention Right arm blood pressure was measured using the Dinamap portable adult/pediatric monitor with appropriate cuff size. Main Outcome Measure Blood pressure levels. Hypertension was defined as either systolic or diastolic blood pressure higher than the 95th percentile for sex, age, and height.
Results: Eight hundred ninety-one children had blood pressure data at 6 years of age: 516 were born at full term; 144 (28%) of the 516 children had a diagnosis of IUGR at birth. At 6 years of age, 93 (19%) of 516 children had hypertension. Of 144 children with IUGR, 35 (24%) had hypertension as compared with 58 (16%) of 372 children without IUGR (P<.05). Twenty percent of cocaine-exposed children had hypertension as compared with 16% of nonexposed children (P = .20). Intrauterine growth restriction status at birth was significantly associated with hypertension (relative risk, 1.8 [95% confidence interval, 1.2-2.7]) when multivariable Poisson regression analysis was performed adjusting for site; maternal race, education, and tobacco, marijuana, alcohol, and cocaine use during pregnancy; and child's current body mass index (calculated as weight in kilograms divided by height in meters squared).
Conclusion: In term infants, IUGR is linked to risk of hypertension in early childhood, which may be a marker for adult cardiovascular disease.