pregnancies in women whose blood pressure at 6 to 11 weeks' gestation was 2170/110 mm Hg. All were given oral treat ment with a-methyldopa and hydralazine to maintain pres sures < 160/1a10 mm Hg. Of the 44 pregnancies, superimposed preeclampsia developed in half, and all adverse perinatal out comes were in this group. Moreover, all neonates of women in the superimposed group were delivered preterm, nearly 80 percent were also growth restricted, and 48 percent sufered perinatal death. Conversely, those women with severe chronic had reasonably good outcomes. There were no perinatal deaths, and only 5 percent of fetuses were growth restricted. Webster and colleagues (2017) found labetalol and nifedipine to be equally efective for chronic hypertension in pregnant women.
Morgan and coworkers (2016a) reported 447 women whose chronic hypertension required treatment beginning prior to 20 weeks. More than half of these women developed superimposed severe preeclampsia. he rate of preeclampsia was 53 percent for those whose 24-hour protein excretion was <300 mg. But for those with antecedent baseline proteinuriaa> 300 mg/day, 79 percent developed severe preeclampsia.
Continuing prepregnancy antihypertensive treatment during pregnancy is debatable for those with mild or moderate hypertension. Although blood pressure reduction certainly beneits the mother long term, it at least theoretically can reduce uteroplacental perfusion. In older observational reports, most pregnancy outcomes in women with mild to moderate hypertension generally were good without treatment and unless superimposed preeclampsia developed (Chesley, 1978; Umans, 2015).
N ewer data are accruing that address potential salutary efects on pregnancy outcomes by simply lowering blood pressure. Earlier studies were relatively small and had widely varying inclusion and outcome criteria. In a Cochrane review of 49 of these studies that included a total of 4723 women with mild to moderate hypertension, Abalos and coworkers (2014) conirmed that the risk for subsequent severe hypertension was lowered with therapy. Compared with untreated women, the frequencies of superimposed preeclampsia, eclampsia, abruption, preterm birth, fetal-growth restriction, and perinatal or maternal mortality did not difer. This latter Cochrane review raised concerns for fetal-growth restriction with 3-blocking
TABLE 50-4. Selected Pregnancy Outcomes in Women with Chronic Hypertension Treated During Pregnancy with and without Baseline Proteinuriaa
Superimposed preeclampsia 79% 49% <0.001 Abruption 0 1% 0.45 EGA at delivery (mean)b 35.1 ± 4.3 wks 37.2 ± 3.3 wks <0.001 ;30 weeks 18% 6% 0.001 ;34 weeks 34% 17% 0.005 ;37 weeks 48% 26% 0.002
Birthweight (mean)b 2379 ± 1028 g 2814 ± 807 g <0.001 ;3rd percentile 20% 9% 0.01 ; 10th percentile 41 % 22% <0.001
Perinatal mortality 36/1000 31/1000 0.47 aDefined as ::300 mgld protein excretion before 20 weeks' gestation. bMean ± standard deviations.
EGA = estimated gestational age.
Data from Morgan, 2016b.