There is a remaining conundrum. We know that approximately 50% of postpartum seizures occur more than 48 hours post delivery. It is vital, therefore, that patients who have hypertensive disorders during pregnancy be educated about the signs and symptoms of postpartum preeclampsia and be given clear directions about how to contact their provider if any signs or symptoms – such as headache, visual disturbances, and right-upper-quadrant pain – are noticed. Patients who are discharged with blood pressures that are still elevated (but not enough to require hospitalization) should be seen again within 72 hours or a week for an evaluation of their blood pressure. The threshold in our practices for arranging earlier postpartum visits, moreover, should be set very low for these women.
The need for patient education is mentioned in the ACOG report, which says, "It is suggested that health care providers convey information about preeclampsia in the context of prenatal care and postpartum care using proven health care communication practices."
The wording of the recommendation as well as its "qualified" strength and the designation of a "low" quality of evidence should not detract from the importance of the message that patient education is a key to successful recognition and management of preeclampsia. The awareness of and knowledge about postpartum preeclampsia have been shown in recent research to be disappointingly low. We need to do better.
With respect to prevention, there are two strategies that, despite not having strong recommendations and/or the backing of high-quality evidence, are still considered to be effective. One is the use of daily low-dose aspirin (60-80 mg) in women with a history of early-onset preeclampsia and preterm delivery prior to 34 weeks’ of gestation. The other is calcium supplementation for women who have an inadequate daily intake of calcium, although this practice has less relevance in the United States than in the developing world.
The goal of low-dose aspirin is really to reduce the likelihood of severe preeclampsia recurring. Almost half of patients with a history of preeclampsia will not develop the disorder in a subsequent pregnancy (without aspirin therapy), so the reduction in the incidence of preeclampsia with low-dose aspirin is unlikely to be significant. However, as aspirin therapy is a relatively benign and inexpensive intervention, it is worth considering. Indeed, meta-analyses of women in randomized trials of low-dose aspirin for preeclampsia prevention have shown small reductions in the incidence and morbidity of preeclampsia, without any evidence of adverse effects.
[Notably, the U.S. Preventive Services Task Force said in a draft recommendation statement issued in April that it recommends low-dose aspirin use after 12 weeks of pregnancy in women who are at high risk for preeclampsia. (See accompanying story.)]
Over the years a variety of predictive strategies – for predicting early-onset preeclampsia in particular – have been proposed and researched, including various biomarkers, blood tests, and imaging studies. These are all worthwhile endeavors at the research level, but for any screening strategy to be implemented there must be an effective intervention. At the current time, our only effective intervention is delivery based on clinical findings.
On the other end of the spectrum, it is clear today that preeclampsia is associated with later-life cardiovascular disease in women. It is only in the last 5-10 years that research findings have come to the fore and that we have thought about preeclampsia as a marker for increased disease risk, just as we did starting several decades ago with gestational diabetes and the risk of future type 2 diabetes.
ACOG’s task force suggests yearly assessment of blood pressure, lipids, fasting blood glucose, and BMI in women with a medical history of preeclampsia who delivered preterm or who have a history of recurrent preeclampsia. The recommendation is "qualified," with a low quality of evidence, and contains a cautionary footnote stating that "the value and appropriate timing of assessment is not yet established."
Indeed, the next step in research will be to follow patients with preeclampsia longitudinally and determine whether or not interventional strategies can be devised to reduce the cardiovascular risk to baseline or, ideally below baseline, in these patients. Until we have such information, we should still recognize that this group of patients may be at higher risk for cardiovascular disease later in life, and, at the very least, be even more vigilant about adhering to regular health maintenance examinations.
Dr. John T. Repke is professor and chair of obstetrics and gynecology at Pennsylvania State University, Hershey, and has published extensively on hypertension in pregnancy. Dr. Repke said he has no relevant financial disclosures.