Editorial Comment

Assessment of maternal blood pressure development during pregnancy Romy Gaillard and Vincent W.V. Jaddoe

See original paper on page 96

G

estational hypertensive disorders are common pregnancy complications and are strongly associated with an increased risk of perinatal morbidity and mortality worldwide [1]. An accumulating body of evidence also suggests that gestational hypertensive disorders have long-term maternal and offspring consequences. Women who suffered from preeclampsia during pregnancy have higher risks of cardiovascular disease many decades after their pregnancy [2]. Offspring from mothers who suffered from gestational hypertensive disorders have an increased risk of higher blood pressure levels in later life [3]. Blood pressure measurement is used as a screening method in obstetric care to predict or detect gestational hypertensive disorders. During normal pregnancy, physiological cardiovascular adaptations occur to meet the increasing demands of the developing fetus. These cardiovascular adaptations lead to a gradual lowering of maternal blood pressure until mid-pregnancy, and a subsequent rise of maternal blood pressure from mid-pregnancy until delivery [4]. Several studies have shown that, also among women without clinically overt gestational hypertensive disorders, higher blood pressure levels during pregnancy are associated with the risk of preterm birth and small size for gestational age at birth [5,6]. Despite the clinical relevance, not much is known about the normal ranges of blood pressure development during pregnancy. In this issue of the Journal of Hypertension, MacdonaldWallis et al. [7] provide gestational age-specific reference ranges for SBP and DBP throughout pregnancy, taking several maternal risk factors into account. Using blood pressure data from 10 327 women participating in the population-based Avon Longitudinal Study of Parents and Children (ALSPAC) study, MacDonald-Wallis et al. constructed longitudinal reference ranges for SBP and DBP from 12 to 40 weeks gestation for nulliparous and Journal of Hypertension 2015, 33:61–62 The Generation R Study Group, Department of Pediatrics, Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands Correspondence to Romy Gaillard, PhD, The Generation R Study Group (Na29-18), Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Tel: +31 10 7043405; fax: +31 10 7044645; e-mail: [email protected] J Hypertens 33:61–62 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. DOI:10.1097/HJH.0000000000000419

Journal of Hypertension

multiparous women. Their analyses were based on a median of 10 [9,11] blood pressure measurements per woman. The authors showed that among healthy-term pregnancies, the normal pattern of SBP and DBP change during pregnancy varies depending on maternal parity, prepregnancy BMI and smoking status. Also, blood pressure level at the first antenatal visit influenced the subsequent pattern of blood pressure change during pregnancy. It is well known that maternal parity, prepregnancy BMI, smoking status and blood pressure level at the first antenatal visit are important factors associated with maternal blood pressure levels during pregnancy and the risk of gestational hypertensive disorders [8–11]. However, thus far, this is the first large, population-based prospective cohort study to construct gestational age-adjusted blood pressure reference ranges for the whole study population, as well as different subgroups of these maternal characteristics. These results are of interest from an etiological perspective, as they provide further insight into normal maternal blood pressure development during pregnancy and the influence of several maternal characteristics on this development. The whole group and subgroup-specific reference ranges may also be useful in clinical practice as a screening method to earlier detect women at higher risk of gestational hypertensive disorders and adverse birth outcomes. Several previous studies have shown that a stronger increase in blood pressure levels in the second half of pregnancy is associated with an increased risk of preeclampsia and fetal growth retardation [4–6,11]. Using these constructed reference charts, women whose blood pressure deviates from the expected normal blood pressure pattern can be identified, which may provide additional information about women at increased risk of adverse pregnancy outcomes. Further research is needed. First, women who participated in the ALSPAC study were more likely to be of higher socio-economic status and white [12]. Therefore, further studies to validate these reference charts among women with a lower socio-economic status and from different ethnic groups are needed. Second, in the current study, MacDonald-Wallis et al. mainly described the SBP and DBP patterns during pregnancy for each maternal characteristic separately. In addition, they studied the blood pressure patterns for nulliparous and multiparous women among those women who were overweight or obese and smoked directly prior to pregnancy or during pregnancy. In these www.jhypertension.com

61

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.

Gaillard and Jaddoe

analyses, the authors thus combine several maternal characteristics for the construction of blood pressure reference ranges. Taking multiple maternal risk factors into account is of utmost interest, especially from a clinical perspective. Customization of reference ranges may be an important step forward for pregnancy care. In the area of obstetric population research, customized fetal growth curves are becoming all the more interesting [13]. Customized fetal growth charts are weight-for-gestational age standards, which take into account various maternal and fetal physiological characteristics [14]. Application of these customized fetal growth charts might improve the distinction between pathological growthrestricted fetuses and fetuses that are small but have reached their growth potential. A similar approach can be applied to develop customized maternal SBP and DBP gestational age-adjusted reference charts, which would take multiple maternal characteristics into account. Whether adding maternal characteristics to the construction of blood pressure reference curves better identifies women with abnormal blood pressure development during pregnancy, as compared to population-based blood pressure reference curves, remains to be further studied. Further research is also needed to examine whether these reference charts improve prediction of adverse pregnancy outcomes. In conclusion, the study by Macdonald-Wallis et al. shows that the pattern of normal blood pressure development during pregnancy is influenced by maternal characteristics. Whether gestational age-specific blood pressure reference ranges, taking into account maternal characteristics, add to the prediction of adverse pregnancy outcomes remains to be further studied.

ACKNOWLEDGEMENTS The authors received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013), project EarlyNutrition under grant agreement no. 289346. V.J. received an additional grant from the Netherlands Organization for Health Research and Development (VIDI 016.136.361).

Conflicts of interest There are no conflicts of interest.

62

www.jhypertension.com

REFERENCES 1. Steegers EA, von Dadelszen P, Duvekot JJ, Pijnenborg R. Preeclampsia. Lancet 2010; 376:631–644. 2. Rich-Edwards JW, Fraser A, Lawlor DA, Catov JM. Pregnancy characteristics and women’s future cardiovascular health: an underused opportunity to improve women’s health? Epidemiol Rev 2014; 36:57–70. 3. Geelhoed JJ, Fraser A, Tilling K, Benfield L, Davey Smith G, Sattar N, et al. Preeclampsia and gestational hypertension are associated with childhood blood pressure independently of family adiposity measures: the Avon Longitudinal Study of Parents and Children. Circulation 2010; 122:1192–1199. 4. Hermida RC, Ayala DE, Iglesias M. Predictable blood pressure variability in healthy and complicated pregnancies. Hypertension 2001; 38 (3 Pt 2):736–741. 5. Bakker R, Steegers EA, Hofman A, Jaddoe VW. Blood pressure in different gestational trimesters, fetal growth, and the risk of adverse birth outcomes: the generation R study. Am J Epidemiol 2011; 174:797– 806. 6. Macdonald-Wallis C, Tilling K, Fraser A, Nelson SM, Lawlor DA. Associations of blood pressure change in pregnancy with fetal growth and gestational age at delivery: findings from a prospective cohort. Hypertension 2014; 64:36–44. 7. Macdonald-Wallis C, Silverwood RJ, Fraser A, Nelson SM, Tilling K, Lawlor DA, de Stavola BL. Gestational-age-specific reference ranges for blood pressure in pregnancy: findings from a prospective cohort. J Hypertens 2015; 33:96–105. 8. Rurangirwa AA, Gaillard R, Steegers EA, Hofman A, Jaddoe VW. Hemodynamic adaptations in different trimesters among nulliparous and multiparous pregnant women; the Generation R study. Am J Hypertens 2012; 25:892–899. 9. Gaillard R, Steegers EA, Hofman A, Jaddoe VW. Associations of maternal obesity with blood pressure and the risks of gestational hypertensive disorders. The Generation R Study. J Hypertens 2011; 29:937–944. 10. Bakker R, Steegers EA, Mackenbach JP, Hofman A, Jaddoe VW. Maternal smoking and blood pressure in different trimesters of pregnancy: the Generation R study. J Hypertens 2010; 28:2210–2218. 11. Gaillard R, Bakker R, Willemsen SP, Hofman A, Steegers EA, Jaddoe VW. Blood pressure tracking during pregnancy and the risk of gestational hypertensive disorders: the Generation R Study. Eur Heart J 2011; 32:3088–3097. 12. Fraser A, Macdonald-Wallis C, Tilling K, Boyd A, Golding J, Davey Smith G, et al. Cohort profile: the Avon Longitudinal Study of Parents and Children: ALSPAC mothers cohort. Int J Epidemiol 2013; 42:97– 110. 13. Gardosi J. Customised assessment of fetal growth potential: implications for perinatal care. Arch Dis Child Fetal Neonatal Ed 2012; 97:F314–F317. 14. Gaillard R, de Ridder MA, Verburg BO, Witteman JC, Mackenbach JP, Moll HA, et al. Individually customised fetal weight charts derived from ultrasound measurements: the Generation R Study. Eur J Epidemiol 2011; 26:919–926.

Volume 33  Number 1  January 2015

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.

Assessment of maternal blood pressure development during pregnancy.

Assessment of maternal blood pressure development during pregnancy. - PDF Download Free
76KB Sizes 0 Downloads 6 Views