LAUSR

It has been controversial regarding blood pressure (BP) levels at which antihypertensive drug therapy should be started in women with hypertensive disorders of pregnancy (HDP), which includes chronic hypertension (CH) as well as hypertension occurring at or after 20 weeks of gestation. In addition, the adequate BP level goal following antihypertensive drug therapy in those with HDP has also been controversial. The Japan Society for the Study of Hypertension in Pregnancy (JSSHP) committee previously recommended that antihypertensive drug therapy should be provided for pregnant women with severe hypertension (more than 160/110 mmHg), and BP should be maintained at 140–160/90–110 mmHg (Fig. 1) [1]. However, considering the recent recommendations of other guidelines [2, 3] and the results of the Control of Hypertension in Pregnancy Study (CHIPS) study [4], the JSSHP committee changed the recommendations for the initial BP levels at which to start antihypertensive drugs and the BP level goal following antihypertensive drug therapy in pregnant women with hypertension in the newest best practice guide (2021) [5]: (1) antihypertensive drug therapy should be used in pregnant women with severe hypertension, for whom BP levels equal to or more than 160/110 mmHg are repeatedly observed; however, it is possible to start antihypertensive drug therapy in pregnant women with BP levels that are ≥140/90 mmHg at the discretion of attending physicians; and (2) the statement for the BP goal following antihypertensive drug therapy in pregnant women with hypertension was retracted. There have been concerns that tight control of BP in pregnancy might be associated with the occurrence of nonreassuring fetal status (NRFS) and/or fetal growth restriction (FGR). Regarding the association between tight BP control and the occurrence of NRFS, to the best of our knowledge, there have been no reports in English suggesting such an association, although it can be easily estimated that extreme control of BP levels in pregnant women with severe hypertension might lead to a significant reduction in uterine blood flow according to the decreasing BP levels, finally increasing the appearance of NRFS. Regarding the association between tight BP control and the occurrence of FGR, von Dadelszen et al. [6] reported an association between a fall in mean arterial pressure (MAP) and FGR in pregnant women with hypertension. In 45 randomized controlled trials (RCTs) including 3773 women with mild-to-moderate pregnancy hypertension, in which either placebo/no therapy or antihypertensive therapy was administered to controls, a greater mean difference in MAP with antihypertensive therapy was associated with higher incidence rates of small-for-gestational age (SGA) infants as well as lower mean birthweight [6]. However, in a recent meta-analysis assessing the effects of antihypertensive drug therapy for women with mild-tomoderate hypertension during pregnancy [7], including 63 trials with 5909 women, the use of antihypertensive drugs had no effect on the risk of SGA infants (adjusted relative risk: 0.96; 95% confidence interval: 0.78–1.18), suggesting that tight BP control might not have been performed in recent trials. Disappointingly, this meta-analysis did not include the CHIPS trial, where the effects of less-tight versus tight control of hypertension on pregnancy complications were assessed, and a target BP to prevent the outcome was not assessed [7]. Abe et al. [8], for the first time, estimated optimal BP levels for the prevention of severe hypertension in pregnant women with nonsevere hypertension by assessing the * Akihide Ohkuchi [email protected]