ACOG urges changes in diagnosis, management of preeclampsia

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New guidelines can simplify management

The report from the ACOG Task Force on Hypertension in Pregnancy marks an important departure from prior diagnostic and management criteria. Firstly, the diagnosis of preeclampsia no longer requires the presence of proteinuria, which can be relatively nonspecific and may also be associated with chronic hypertension. Rather, the task force includes evidence of maternal hepatic, renal, pulmonary, and cerebral end-organ disease in the diagnostic criteria – even in the absence of proteinuria. Once the diagnosis of preeclampsia has been established, the severity criteria no longer include fetal growth restriction, but rather focus on maternal symptoms. Thirdly, delivery is suggested for women with preeclampsia at 37 0/7 weeks’ gestation even in the absence of severe features, and special emphasis is placed on modifying analgesic therapy for women who fail to normalize their blood pressure after the first postpartum day.

Dr. Ahmet A. Baschat

These changes are based on evidence and partly choice. The choice to recognize nonproteinuric preeclampsia as a diagnostic entity follows in the footsteps of several international bodies. Now, women with new-onset hypertension and end-organ effects can be diagnosed with preeclampsia, and management can be based on severity criteria and gestational intervention thresholds without any potentially dangerous delay due to the absence of proteinuria. This important change has the potential to decrease maternal mortality that is attributable to delayed intervention.

The second important step is to remove fetal growth restriction as a severity criterion. This offers the advantage to manage maternal and fetal disease independently based on their individual severities. In the setting of disease-specific surveillance including umbilical artery Doppler ultrasound, this approach has the potential benefit of minimizing iatrogenic prematurity – an important contributor to adverse neonatal outcome.

One choice that the task force did not make is to emphasize the opportunity of first-trimester screening for preeclampsia. Standardized maternal blood pressure readings at this time both are an integral component of screening algorithms and provide additional diagnostic opportunity to document preexisting hypertension – critical for the later diagnosis of preeclampsia (Hypertension 2008;51:1027-33). In addition, the task force underemphasizes the importance of early initiation of low-dose aspirin, because the benefit is greatest for women initiating prophylaxis prior to 16 weeks, and risks for placental abruption increase with initiation in the second trimester (J. Obstet. Gynaecol. Can. 2009;31:818-26). This is important for those centers that choose to provide an early risk assessment, and based on that, initiate low-dose aspirin.

In summary, I think these changes offer a clear advantage by increasing the diagnostic specificity for preeclampsia and providing severity stratification that bears closer relevance to maternal and neonatal outcome. Accordingly, a simplified but clear management approach can be developed, tailored on the balance of disease severity and gestational age.

Dr. Ahmet A. Baschat is professor of obstetrics, gynecology, and reproductive sciences, and director of maternal fetal medicine and the section of fetal therapy at the University of Maryland in Baltimore. He was asked to comment on the task force report. Dr. Baschat said he had no financial disclosures relevant to the report.



Proteinuria, or elevated protein in the urine, should no longer be considered the signature criterion besides new-onset hypertension in diagnosing preeclampsia, says the American College of Obstetricians and Gynecologists.

In exhaustive new clinical guidelines on hypertension in pregnancy, ACOG says that equal weight should be given to reduced platelet counts, renal insufficiency, severe headache, heart-lung compromise, and impaired liver function. Any one of these concurrent with new-onset hypertension at 20 weeks of pregnancy or beyond is enough to establish preeclampsia, even in the absence of proteinuria.

"Clinicians like hard numbers," said Dr. James N. Martin, chief of the division of maternal-fetal medicine at the University of Mississippi Medical Center in Jackson, a past ACOG president, and an author of the guidelines. "But sometimes we can be misled by them." Reviews of maternal mortality data have shown that waiting for proteinuria to present can result in delayed intervention or missed diagnosis, as not all women with preeclampsia will develop proteinuria.

The new guidelines replace recommendations from a 2002 ACOG Practice Bulletin (Obstet. Gynecol. 2002;99:159-67). In addition to the revised diagnostic recommendations and precisely defined measures to determine severity of disease, they address several important management challenges: preeclampsia on top of an existing hypertensive disorder; timing of induction for preeclampsia with and without severe symptoms; use of corticosteroids; and recognizing and managing preeclampsia in the postpartum period.

The guidelines do emphasize one hard number that should be useful to clinicians: Delivery at 37 weeks is advised for women with preeclampsia without severe features.

Dr. Martin said that the 37-week delivery recommendation was based largely on results from a 2009 trial in Holland in which 756 women were randomized to induction at the 36- to 37-week point or expectant monitoring to await labor; induction at 37 weeks was associated with poor outcomes in only 31% of subjects, compared with 44% of those receiving expectant monitoring.

The guidelines distinguish extensively between preeclampsia with and without severe features, but discourage the use of the phrase "mild preeclampsia," considering it misleading. "Preeclampsia in any form should never be minimized as ‘mild,’ " Dr. Martin said.

Proteinuria, in addition to being downgraded as the signature diagnostic finding in preeclampsia, should no longer be considered as useful in classifying preeclampsia as severe or in deciding whether to induce, the guidelines say, because the amount of protein in the urine has not been shown to predict either maternal or fetal outcomes.

Fetal growth restriction, once considered a major criterion to make the diagnosis of severe preeclampsia, is now to be used not for diagnosis of preeclampsia, but for indicated delivery in a patient with preeclampsia who also has an extremely small fetus (less than 5th centile) that is associated with abnormal blood flow findings in the umbilical cord connecting the fetus to the placenta.

The guidelines emphasize that preeclampsia can appear for the first time following delivery, or worsen rather than improve during in the postnatal period. It is advisable that all postpartum patients become educated about symptoms suggestive of new or worsening preeclampsia after leaving the hospital so that the patient’s doctors can be alerted and treatment begun in time to prevent problems.

On the prevention front, the guidelines have less to recommend. The use of vitamins C and E is not advised in preventing preeclampsia. Low-dose aspirin, however, is recommended starting late in the first trimester for patients who experience preterm severe preeclampsia.

"What we really need are biomarkers," Dr. Martin said, adding that despite encouraging science on placental growth factor and other potential early markers, none is yet ready for routine clinical use.

Some of the guidelines’ coauthors reported financial relationships or potential conflicts of interest. Dr. George Bakris disclosed associations with Takeda, CVRx, and other companies. Dr. John Barton disclosed relationships with Alere and Beckman Coulter. Dr. Ananth Karumanchi disclosed relationships with Beckman Coulter, Roche, and others. Dr. Baha Sibai disclosed a relationship with Alere. The remaining task force members said they had no relevant financial disclosures.

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