Women with well-controlled chronic hypertension who have no complicating factors can generally be expected to have a good pregnancy outcome. Because even those with mild hypertension have a greater risk of superimposed preeclampsia and fetal-growth restriction, serial antepartum assessment of fetal well-being is recommended by many. That said, according to the American College of Obstetricians and Gynecologists (2013), with the exception of sonographic fetal-growth monitoring, described in Chapter 44 (p. 852), no conclusive data address either benefit or harm associated with various antepartum surveillance strategies.
• Expectant Management of Early-Onset
Given that many women with chronic hypertension develop superimposed preeclampsia before term, considerations for expectant management may be reasonable in some cases. In a study from Magee-Women's Hospital, 41 careully selected women with a median gestational age of 31.6 weeks were expectantly managed (Samuel, 2011). Despite liberal criteria to mandate delivery, 17 percent developed either placental abruption or pulmonary edema. The latency period was extended by a mean of 9.7 days. There were no perinatal deaths, however, salutary outcomes were similar. These investigators recommend randomized trials to study expectant management before this becomes usual care.
For chronically hypertensive women who have complications such as fetal-growth restriction or superimposed preeclampsia, the decision to deliver is made by clinical judgment. The route of delivery is dictated by obstetrical factors. Certainly, most women with superimposed severe preeclampsia are better delivered even when the fetus is markedly preterm. Increased risk for placental abruption, cerebral hemorrhage, and peripartum heart failure attend delivery delays (Cunningham, 1986, 2005; Martin, 2005).
For women with chronic hypertension without preeclampsia, expectant management at later gestational ages was reported recently by Harper and colleagues (2016). They concluded that expectant management beyond 39 weeks' gestation was associated with an increasing incidence of severe preeclampsia and that planned delivery before 37 weeks was associated with a rise in rates of adverse neonatal outcomes.
For women with mild to moderate chronic hypertension who continue to have an uncomplicated pregnancy, the merican College of Obstetricians and Gynecologists (2013) recommends delivery not be pursued until 38°17 weeks. The consensus committee indings by Spong and associates (2011) recommend consideration for delivery at 38 to 39 weeks, that is, :::37 completed weeks. A trial of labor induction is preferable, and many of these women respond favorably and will be delivered vaginally (Alexander, 1999; Atkinson, 1995).
For women with severe preeclampsia, peripartum management is the same as described in Chapter 40 (p. 729). Epidural analgesia for labor and delivery is optimal with the caveat that it is not given to treat hypertension (Lucas, 2001). hat said, women with severe superimposed preeclampsia are more sensitive to the acute hypotensive efects of epidural analgesia (Vricella, 2012). Also in this group, magnesium sulfate neuroprophylaxis is initiated for prevention of eclampsia. Severe hypertension-diastolic blood pressure :::110 mm Hg or systolic pressurea:::160 mm Hg-is treated with either intravenous hydralazine or labetalol. Some prefer to treat women when the diastolic pressure reaches 100 to 105 mm Hg. Vigil-De Gracia and colleagues (2006) randomly assigned 200 women to intravenous hydralazine or labetalol to acutely lower severe high blood pressure in pregnancy. Outcomes were similar except for significantly more maternal palpitations and tachycardia with hydralazine and signiicantly more neonatal hypotension and bradycardia with labetalol.