Identify Patients at Risk Early
The status of any comorbidities, such as high BMI or high blood pressure, should be optimized before conception, and vigilant monitoring—including early and serial ultrasonography, uterine Doppler assessment at 18-20 weeks, and laboratory testing as indicated—should be instituted to minimize and manage her risk.
By detecting complications early and monitoring for signs and symptoms of preeclampsia—and then hospitalizing her if you detect severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia—you can ensure optimal outcomes.
This patient will probably want to know about the value of various biomarkers and supplements, such as fish oil and vitamins C and E, and again, we need to explain that the best studies have shown minimal to no benefit and do not support their use.
The three large randomized trials looking at vitamin E supplementation, for example, showed no effect on the rate of preeclampsia, its severity, or the rate of adverse neonatal outcomes.
None of the randomized trials on calcium supplementation included women with a previous history of preeclampsia, so the benefit for this indication remains unclear. Nevertheless, because calcium is beneficial for any pregnancy, we recommend it.
The greatest benefits of low-dose aspirin may come for this patient. A recent meta-analysis of 31 randomized trials found a 14% reduction in recurrent preeclampsia—higher than that seen for first-time preeclampsia (Lancet 2007;369:1791-8). Low-dose aspirin has also proved to be safe. We recommend 81 mg daily beginning at 12 weeks' gestation, and suggest discontinuing aspirin with the development of preeclampsia.
If the patient has documented evidence of antiphospholipid antibody syndrome, she should receive prophylactic-dose heparin in addition to low-dose aspirin once fetal viability is confirmed.
A woman who had late-occurring mild preeclampsia in her first pregnancy, and is planning a second child.
This patient experienced the most common presentation of preeclampsia, and fortunately has a fairly low risk for recurrence (about 10%). Chances are also likely that if preeclampsia recurs, it will recur at term.
This risk can be minimized and a good outcome ensured by following the same approach to history taking, counseling, and optimizing health before conception, as well as careful monitoring during pregnancy to detect complications early.
Risks Later in Life
Today, counseling women with a history of preeclampsia involves more than assessing and minimizing risks for recurrence of the disorder. It also involves discussing the now-substantial body of literature that suggests that women whose pregnancies are complicated by preeclampsia and/or fetal growth restriction have an increased risk for future cardiovascular disease and ischemic stroke.
These women require close follow-up after their pregnancies so that their long-term risks can be reduced or avoided through the use of preventive strategies and approaches to care.
Preeclampsia and fetal growth restriction are both vascular-related pregnancy complications, and they share similar risk factors and pathophysiological abnormalities, such as endothelial dysfunction.
It's unclear exactly what mechanisms account for the relationship among these complications and the increased risk of subsequent cardiovascular disease, but it increasingly seems likely that these women have a predisposition to vascular and metabolic disease: a constitutional risk.
Epidemiologic and case-control studies published in the last 10 years—many of them in the nonobstetric literature—have evaluated the associations, and last year a systematic review and meta-analysis of these studies reported a relative risk for chronic hypertension of 3.7 after approximately 14 years of average follow-up, a relative risk of 2.16 for ischemic heart disease after about 11 years of follow-up, and a relative risk of 1.8 for ischemic stroke after about 10 years (BMJ 2007;335:974-85).
In addition, overall mortality after preeclampsia was increased by a relative risk of approximately 1.5 after 14.5 years of follow-up.
In a recently published intergenerational case-control study, Dutch investigators looked at 106 women whose pregnancies were complicated by preeclampsia or fetal growth restriction, a control group of 106 women with normal pregnancies, and each woman's mother and father.
They found significant intergenerational similarities in cardiovascular risk profiles between the women after preeclampsia or fetal growth restriction and their parents, such as higher fasting glucose levels that could not be explained by differences in BMI.
Intergenerational similarities were also found for hypertension, waist circumference, and metabolic syndrome (Hypertension 2008;51:1034-41).
ELSEVIER GLOBAL MEDICAL NEWS
Preeclampsia, Part 3
The exact incidence of preeclampsia is unknown, but in its mild form it is estimated to affect up to 10% of all pregnancies. Indeed, it is one of the most common complications of pregnancy. In a smaller number of cases (just under 1% of pregnancies), the disorder develops as severe preeclampsia.
