Preeclampsia has been redefined
In recognition of preeclampsia’s multiorgan involvement, the American College of Obstetricians and Gynecologists modified the diagnostic criteria: proteinuria is not essential for diagnosis. The diagnosis may be made with the presence of hypertension plus the new onset of any one of thrombocytopenia, renal insufficiency, liver dysfunction, pulmonary edema, or cerebral or visual disturbances.1
Preeclampsia is a syndrome rather than one disease
Near-term preeclampsia, occurring after 34 weeks’ gestation, is often accompanied by increased cardiac output, mildly increased total vascular resistance and normal fetal growth.2 By contrast, preterm preeclampsia — often associated with reduced maternal cardiac output, markedly elevated total vascular resistance and intrauterine growth restriction (IUGR)2 — is more ominous and warrants aggressive surveillance of mother and fetus.
Preeclampsia increases the risk of premature cardiometabolic disease in women
Women with preeclampsia, especially early-onset preeclampsia, have a risk of premature cardiovascular disease and death five times higher than that among unaffected women, and a significantly higher risk of chronic kidney disease and type 2 diabetes mellitus.1 Lifestyle modification after delivery is recommended, including a healthy weight, moderate physical activity, avoidance of smoking, and periodic surveillance of blood pressure, glucose and lipids.1
Established risk factors should be used to screen for preeclampsia
Screening using clinical risk factors is recommended3,4 and can be done efficiently by physicians, nurses or midwives. A list of risk factors is presented in Box 1.
Box 1: Screening for preeclampsia before 16 weeks’ gestation based on clinical risk factors.
Women should be considered at increased risk of preeclampsia if they have one major risk factor or at least two moderate risk factors
Major risk factors
Prior preeclampsia
Known antiphospholipid syndrome
Known type 1 or type 2 diabetes mellitus
Chronic hypertension
Assisted reproductive therapy in current pregnancy
Pre-pregnancy or early first-trimester BMI > 30
Moderate risk factors
Prior placental abruption
Prior stillbirth
Prior fetal IUGR
Maternal age > 40 yr
Nulliparity
Multifetal pregnancy
Known chronic kidney disease
Known systemic lupus erythematosus
Note: BMI = body mass index, IUGR = intrauterine growth restriction.
Preeclampsia can be prevented
In women identified to be at high risk of preeclampsia, the risk can be reduced substantially with low-dose acetylsalicylic acid (ASA) (e.g., 81 mg at bedtime) at 12–20 weeks’ gestation, stopped at 37–38 weeks. The use of ASA is safe for mother and fetus. It confers a 24% reduction in relative risk for preeclampsia (95% confidence interval [CI] 5%–38%), a 20% reduction for IUGR (95% CI 1%–35%) and a 24% reduction for preterm birth (95% CI 2%–24%).5
Acknowledgement
The authors acknowledge the contribution of Dr. Joel Ray in the preparation of this manuscript.
Footnotes
Competing interests: None declared.
This article has been peer reviewed.
References
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