Hypertensive disorders affect around 10 % of all pregnant and postpartum women worldwide and represent an important cause of maternal mortality [1], [2]. Hypertensive diseases have been a particularly important cause of death in Latin America and the Caribbean [2]. In Brazil, hypertension remains the principal cause of maternal mortality [3]. The postpartum period is as risky as pregnancy, since almost 50 % of deaths occur postpartum [4], and women can be particularly susceptible to hypertensive disorders in the early postpartum period [5].

Some antihypertensives such as hydralazine, slow-release nifedipine, methyldopa and labetalol are recommended during pregnancy in view of their reduced risk of fetal abnormalities and their proven effectiveness [5], [6], [7]. In the postpartum period, although lactation should always be taken into consideration [5], from the point of view of the recently delivered woman, any class of antihypertensive can be used, including the angiotensin-converting enzyme (ACE) inhibitors, which are contraindicated during pregnancy [6], [8], but can be more beneficial in the postpartum period than other antihypertensives insofar as renal protection and improved cardiac function are concerned [9].

In practice, methyldopa is the most commonly used hypertensive drug during pregnancy [5], [6], due both to its documented fetal safety and easy access, particularly within the public health sector of developing countries [10]. Nevertheless, although also safe during breastfeeding, it should be avoided in the postpartum period because of the risk of postpartum depression [5]. Therefore, in the early postpartum period, it is common clinical practice in Brazil to switch methyldopa for another class of antihypertensive immediately following delivery. This could, however, generate a consequent, albeit rare, rebound effect [11], [12]. Furthermore, treatment change could lead to an initial loss of blood pressure control until the full effect of the new drug is achieved, resulting in prolonged hospitalization [13]. In some healthcare services, methyldopa is routinely maintained in the postpartum period, also taking into consideration the possibility of a further pregnancy after this period [7].

Managing hypertension during pregnancy has been widely discussed [5], [6], [10]; however, few studies have dealt with the postpartum period [14], [15], [16]. Consequently, the treatment of hypertension in the postpartum period is generally guided by specialist opinion and guidelines based on studies with a low level of evidence [17].

This study aimed to compare the continued use of methyldopa in the early postpartum period with switching it for another class of antihypertensive to control blood pressure in postpartum women with hypertensive syndromes. The drug used in this study was captopril, an ACE inhibitor with a similar time interval between doses to that of methyldopa (every eight hours), which is widely used in clinical practice and available within the public healthcare sector.

Based on the aforementioned considerations, it is reasonable to conclude that the ideal first-line agent for the treatment of postpartum hypertension remains to be determined. Therefore, more consistent evidence is required to evaluate which antihypertensive agent is the most effective in controlling blood pressure in the postpartum period [17]. The objective of the present study was to evaluate blood pressure control in hypertensive patients in the first 48 h postpartum, comparing those who maintained the use of methyldopa following delivery with patients who switched from methyldopa to another antihypertensive agent, in this case captopril.