Modifiable maternal exposures and offspring blood pressure: a review of epidemiological studies of maternal age, diet and smoking

Prenatal programming of adult disease is well established in animals. In humans the impact of common in utero exposures on long-term offspring health is less clear. We reviewed epidemiology studies of modifiable maternal exposures and offspring blood pressure (BP). Three maternal exposures were identified for review and meta-analysed where possible: smoking during pregnancy, diet and age at childbirth. Meta-analysis suggested there was a modest association between higher offspring BP and prenatal exposure to smoke (confounder-adjusted [beta]=0.62 mmHg, 95% confidence interval (CI): 0.19 to 1.05, I2=16.4%). However, the level of confounder adjustment varied between studies, which in some studies attenuated the association to the null. There was no strong evidence that any component of maternal diet during pregnancy (maternal protein, energy, calcium and various other nutrients) influences offspring BP. The results of studies of maternal age varied and there was strong evidence of heterogeneity in the pooled analysis. The association with maternal age, if present, was modest (confounder-adjusted [beta]=0.09 mmHg/year, 95% -0.03 to 0.21, I2=89.8%). In sum, there is little empirical evidence that the maternal exposures reviewed program offspring BP. Other components of offspring health may be more susceptible to effects of programming in utero.