The impact of maternal body mass index on the phenotype of pre-eclampsia: a prospective cohort study

• Published in: BJOG : an international journal of obstetrics and gynaecology Vol. 119; no. 5; pp. 589 - 595
• Main Authors: Anderson, NH, McCowan, LME, Fyfe, EM, Chan, EHY, Taylor, RS, Stewart, AW, Dekker, GA, North, RA
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-2012; Blackwell; Wiley Subscription Services, Inc
• Subjects: Adult; Australia; Biological and medical sciences; Body Mass Index; Diseases of mother, fetus and pregnancy; Female; Fetal Macrosomia; Genotype & phenotype; Gynecology. Andrology. Obstetrics; Humans; Infant, Newborn; Infant, Small for Gestational Age; Kaplan-Meier Estimate; Medical sciences; New Zealand; obesity; overweight; Overweight - complications; Placental Circulation - physiology; Pre-Eclampsia - etiology; Pre-Eclampsia - physiopathology; Preeclampsia; Pregnancy; Pregnancy Outcome; pregnancy outcomes; Pregnancy Trimester, Third; Pregnancy. Fetus. Placenta; preterm pre-eclampsia; Prospective Studies; small for gestational age; term pre-eclampsia; Ultrasonography, Doppler; Ultrasonography, Prenatal; Uterine Artery - physiology; New Zealand; Australia; Body mass index; Phenotype; Pregnancy disorders; Mother; Cohort study; Gynecology; Preeclampsia; Obstetrics; Pregnancy toxemia
• DOI: 10.1111/j.1471-0528.2012.03278.x
• EISSN: 1471-0528
• ISSN: 1470-0328

Please cite this paper as: Anderson N, McCowan L, Fyfe E, Chan E, Taylor R, Stewart A, Dekker G, North R, on behalf of the SCOPE Consortium. The impact of maternal body mass index on the phenotype of pre‐eclampsia: a prospective cohort study. BJOG 2012;119:589–595.
Objective  We hypothesised that among nulliparous women with pre‐eclampsia, overweight or obese women would have a different phenotype of pre‐eclampsia compared with normal weight women with pre‐eclampsia. Specifically, they are more likely to develop term pre‐eclampsia and less likely to have indicators of impaired placental perfusion, e.g. abnormal uterine artery Doppler or a small‐for‐gestational‐age (SGA) infant.
Design  Prospective, multicentre, cohort SCOPE study (n = 3170).
Setting  New Zealand and Australia.
Population  Nulliparous women who developed pre‐eclampsia.
Methods  Participants were interviewed at 14–16 weeks of gestation, uterine artery Doppler studies were performed at 19–21 weeks and pregnancy outcome was tracked prospectively.
Main outcome measures  Rates of abnormal uterine artery Doppler indices, term/preterm birth and SGA infants were compared between normal, overweight and obese women with pre‐eclampsia. Multivariable analysis was performed to examine the association between body mass index (BMI) and term pre‐eclampsia.
Results  Of 178 women with pre‐eclampsia, one underweight woman was excluded and 66 (37%) were normal weight, 52 (29%) were overweight and 59 (34%) were obese. Pre‐eclampsia developed preterm in 26% of women and at term in 74% of women. There were no differences in the rates of term/preterm pre‐eclampsia, abnormal uterine artery Doppler indices or SGA infants between BMI groups (P > 0.10). No independent association between BMI and term pre‐eclampsia was found (P = 0.56).
Conclusions  Among women with pre‐eclampsia, those who are overweight or obese in early pregnancy are not more likely to have term pre‐eclampsia compared with women with a normal BMI. Overweight and obese women require vigilant surveillance for the development of preterm as well as term pre‐eclampsia.