Cord Blood Vitamin D and Preeclampsia Associated with Blood Pressure in Offspring Children and Youth

Written by Joyce Smith, BS. This study finds that adequate maternal prenatal vitamin D levels may help prevent the development of high blood pressure in children and youth of mothers who were preeclamptic.

Preeclampsia is a condition in pregnancy characterized by high blood pressure, sometimes with fluid retention and proteinuria. It is a major cause of illness and death for pregnant women, affecting two to eight percent of pregnancies worldwide ¹ and is associated with a greater risk of stillbirth and preterm birth. Since the 1980’s, preeclampsia has increased by 25% ² and with it elevated levels of childhood blood pressure have occurred ³. Ample evidence supports the association of high childhood BP with hypertension and cardiovascular diseases in adulthood ⁴. Also associated with increased CVD and  preeclampsia are vitamin D levels, and considering the role of vitamin D in fetal development ⁵, higher infancy levels of this vitamin may protect against high BP in childhood ⁶.

The objective of this study ⁷ was to examine the association between preeclampsia and offspring  systolic BP levels across three groups of childhood development: early childhood (3-5yrs), middle childhood (6-12 years) and adolescence (13-18 years) and to examine whether cord Vitamin D blood effects this association. Data was analyzed on 754 mother-child pairs enrolled from 1998 to 2018 in the Boston Birth Cohort. Follow-up analysis occurred from 2002-2018 and final data analysis occurred from 2019-2020.  The dataset included information on preeclampsia during pregnancy, tests on umbilical cord blood at birth, and children’s blood pressure from ages 3 to 18.

This study cohort consisted of 62% blacks and 19% Hispanics of which 10.5% were preeclampsic and  19% of births were premature. A total of 6,669 BP readings were done on 754 children ages 3 to 18 years (50% female, 19% preterm: 672 (89.1%) of children had BP measurements in early childhood, 650 (86.2%) in middle childhood, and 143 (19.0%) in adolescence.

Researchers found that maternal preeclampsia was associated with higher child BP from childhood to adolescence. Compared with children born to mothers without preeclampsia, those born to mothers with preeclampsia had 5.34 (95%CI, 1.37-9.30) percentile higher BP after adjusting for confounders. This association, however, varied by cord blood 25(OH)D levels where higher cord blood 25(OH)D was associated with lower childhood BP. When defining vitamin D deficiency as cord blood 25(OH)D less than 20 ng/mL, the association between maternal preeclampsia and child BP percentile was 7.49 (95%CI, 3.13-11.85) for those with vitamin D deficiency and −4.19 (95%CI, −13.26 to 4.88) for those without vitamin D deficiency.  After adjustment for confounders, children born to mothers with preeclampsia had 3.47 (95%CI, 0.77-6.18) percentile lower BP per 5 ng/mL increment in cord blood 25(OH)D.

Possible explanations for these findings include an existing association between preeclampsia and  vascular and cardiac abnormalities that involve higher levels of inflammation and oxidative stress ⁸. The possibility of sexually dimorphic associations ⁹, genetic predispositions to preeclampsia ¹⁰ and family environment and lifestyle characteristics may also contribute to the vitamin D-BP association in the offspring. Possible limitations include the fact that 8.9% of children had only one BP reading, and no adjustments for cofounders such as education and socioeconomic status were made.

Since adequate cord blood 25(OH)D levels may modify the association between lower cord blood 25(OH)D levels and higher child BP levels, researchers recommend that for mothers who experience preeclampsia during pregnancy, optimizing vitamin D levels may protect their children from developing high BP and future cardiovascular diseases.  Further studies are recommended to confirm this benefit.

Source: Zhang, Mingyu, Erin D. Michos, Guoying Wang, Xiaobin Wang, and Noel T. Mueller. “Associations of Cord Blood Vitamin D and Preeclampsia With Offspring Blood Pressure in Childhood and Adolescence.” JAMA Network Open 3, no. 10 (2020): e2019046-e2019046.

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Posted October 20, 2020.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

1. Steegers EA, von Dadelszen P, Duvekot JJ, Pijnenborg R. Pre-eclampsia. Lancet. 2010;376(9741):631-644.
2. Wallis AB, Saftlas AF, Hsia J, Atrash HK. Secular trends in the rates of preeclampsia, eclampsia, and gestational hypertension, United States, 1987-2004. Am J Hypertens. 2008;21(5):521-526.
3. Rosner B, Cook NR, Daniels S, Falkner B. Childhood blood pressure trends and risk factors for high blood pressure: the NHANES experience 1988-2008. Hypertension. 2013;62(2):247-254.
4. Yang L, Magnussen CG, Yang L, Bovet P, Xi B. Elevated Blood Pressure in Childhood or Adolescence and Cardiovascular Outcomes in Adulthood: A Systematic Review. Hypertension. 2020;75(4):948-955.
5. Wagner CL, Hollis BW. The Implications of Vitamin D Status During Pregnancy on Mother and her Developing Child. Front Endocrinol (Lausanne). 2018;9:500.
6. Wang G, Liu X, Bartell TR, Pearson C, Cheng TL, Wang X. Vitamin D Trajectories From Birth to Early Childhood and Elevated Systolic Blood Pressure During Childhood and Adolescence. Hypertension. 2019:Hypertensionaha11913120.
7. Zhang M, Michos ED, Wang G, Wang X, Mueller NT. Associations of Cord Blood Vitamin D and Preeclampsia With Offspring Blood Pressure in Childhood and Adolescence. JAMA Netw Open. 2020;3(10):e2019046.
8. Davis EF, Newton L, Lewandowski AJ, et al. Pre-eclampsia and offspring cardiovascular health: mechanistic insights from experimental studies. Clinical science (London, England : 1979). 2012;123(2):53-72.
9. Schalekamp-Timmermans S, Arends LR, Alsaker E, et al. Fetal sex-specific differences in gestational age at delivery in pre-eclampsia: a meta-analysis. Int J Epidemiol. 2017;46(2):632-642.
10. Gray KJ, Kovacheva VP, Mirzakhani H, et al. Gene-Centric Analysis of Preeclampsia Identifies Maternal Association at PLEKHG1. Hypertension. 2018;72(2):408-416.