ABO and RhD blood groups and gestational hypertensive disorders: a population-based cohort study.
OBJECTIVE
To examine the association between ABO and RhD blood groups and gestational hypertensive disorders in a large population-based cohort.


METHODS
Cohort study. Risks of gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia, estimated by odds ratios for maternal ABO blood group and RhD status.


METHODS
National health registers of Sweden.


METHODS
All singleton deliveries in Sweden born to first-time mothers during the period 1987-2002 [total n = 641 926; any gestational hypertensive disorders, n = 39 011 (6.1%); pre-eclampsia cases, n = 29 337 (4.6%); severe pre-eclampsia cases, n = 8477 (1.3%)].


METHODS
Using blood group O as a reference, odds ratios of gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia were obtained from logistic regression models adjusted for potential confounding factors.


METHODS
Gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia.


RESULTS
Compared with blood group O, all non-O blood groups had modest but statistically significantly higher odds of pre-eclampsia. Blood group AB had the highest risk for pre-eclampsia (OR = 1.10, 95% CI 1.04-1.16) and severe pre-eclampsia (OR = 1.18, 95% CI 1.07-1.30). RhD-positive mothers had a small increased risk for pre-eclampsia (OR = 1.07, 95% CI 1.03-1.10).


CONCLUSIONS
In the largest study on this topic to date, women with AB blood group have the highest risks of gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia, whereas women with O blood group have the lowest risks of developing these disorders. Although the magnitude of increased risk is small, this finding may help improve our understanding of the etiology of pre-eclampsia.
Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, PA, USA.
B K
BK
Lee
Z
Z
Zhang
A
A
Wikman
P G
PG
Lindqvist
M
M
Reilly
D000017:ABO Blood-Group System / Q000502:physiology*; D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood* / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000097:blood* / Q000453:epidemiology; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System / Q000502:physiology*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
D000017:ABO Blood-Group System; D012204:Rh-Hr Blood-Group System