Managing hypertension in pregnancy: New recommendations
American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 202. Gestational hypertension and preeclampsia. Obstet Gynecol. 2019;133:e1-e25.
In 2013, ACOG released "Hypertension in pregnancy," a 99-page comprehensive document developed by their Task Force on Hypertension in Pregnancy, to summarize knowledge on the subject, provide guidelines for management, and identify needed areas of research.9 I summarized key points from that document in the 2014 "Update on Obstetrics" (OBG Manag. 2013;26:28-36). Now, ACOG has released 2 Practice Bulletins—"Gestational hypertension and preeclampsia" and "Chronic hypertension in pregnancy"—that replace the 2013 document.10,11 These Practice Bulletins are quite comprehensive and warrant a thorough read. Several noteworthy changes relevant to the practicing obstetrician are summarized below.
Highlights of revised guidance
Expectant management vs early delivery in preeclampsia with fetal growth restriction. Fetal growth restriction, which was removed from the definition of preeclampsia with severe features in 2013, is no longer an indication for delivery in preeclampsia with severe features (previously, if the estimated fetal weight was < 5th percentile for gestational age, delivery after steroid administration was recommended). Rather, expectant management is reasonable if fetal antenatal testing, amniotic fluid, and Doppler ultrasound studies are reassuring. Abnormal umbilical artery Doppler studies continue to be an indication for earlier delivery.
Postpartum NSAID use in hypertension. The 2013 document cautioned against nonsteroidal anti-inflammatory drug (NSAID) use postpartum in women with hypertensive disorders of pregnancy because of concern for exacerbating hypertension. The updated Practice Bulletins recommend NSAIDs as the preferred choice over opioid analgesics as data have not shown these drugs to increase blood pressure, antihypertensive requirements, or other adverse events in postpartum patients with blood pressure issues.
More women will be diagnosed with chronic hypertension. Recently, the American College of Cardiology and the American Heart Association changed the definition of hypertension. Stage 1 hypertension is now defined as a systolic blood pressure of 130-139 mm Hg or a diastolic blood pressure of 80-89 mm Hg. Treatment of stage 1 hypertension is recommended for nonpregnant adults with risk factors for current or future cardiovascular disease. The potential impact is that more women will enter pregnancy with a diagnosis of chronic hypertension, and more may be on prepregnancy antihypertensive therapy that will need to be addressed during the pregnancy.
Blood pressure goals. The target blood pressure range for pregnant women with chronic hypertension is recommended to be ≥ 120/80 mm Hg and < 160/110 mm Hg (this represents a slight change, as previously diastolic blood pressure was to be < 105 mm Hg). Postpartum blood pressure goals of < 150/100 mm Hg remain the same.
Managing acute hypertensive emergencies. Both Practice Bulletins emphasize the importance of aggressive management of acute hypertensive emergency, with options for 3 protocols: labetalol, nifedipine, and hydralazine. The goal is to administer antihypertensive therapy within 30 to 60 minutes, but administration as soon as feasibly possible after diagnosis of severe hypertension is ideal.
Timing of delivery. Recommended delivery timing in patients with chronic hypertension was slightly altered (previous recommendations included a range of 37 to 39 6/7 weeks). The lower limit of gestational age for recommended delivery timing in chronic hypertension has not changed—it remains not before 38 weeks if no antihypertensive therapy and stable, and not before 37 weeks if antihypertensive therapy and stable.
The upper limit of 39 6/7 weeks is challenged, however, because data support that induction of labor at either 38 or 39 weeks reduces the risk of severe hypertensive complications (such as superimposed preeclampsia and eclampsia) without increasing the risk of cesarean delivery. Therefore, for patients with chronic hypertension, expectant management beyond 39 weeks is cautioned, to be done only with careful consideration of risks and with close surveillance.
As with ACOG’s original Task Force document on hypertension, clinicians should thoroughly read these 2 Practice Bulletins on hypertension in pregnancy as there are subtle changes that affect day-to-day practice, such as the definition of hypertension prior to pregnancy, treatment guidelines, and delivery timing recommendations. As always, these are guidelines, and the obstetrician’s clinical judgment and the needs of specific patient populations also must be taken into account.