Lasix for the Prevention of De Novo Postpartum Hypertension

Hypertensive disorders of pregnancy are one of the leading causes of maternal morbidity and mortality worldwide. The majority of clinical research has focused on pregnancy-related hypertension that develops in the antenatal period, while studies of the incidence, risk factors, and prevention of postpartum hypertension are limited. In particular, there is a paucity of data about the clinical entity known as de novo postpartum hypertension, in which women who are normotensive throughout pregnancy and delivery subsequently go on to develop high blood pressure in the immediate to late postpartum period. Of those with postpartum preeclampsia, 33-69% were normotensive antepartum.

Early identification and treatment of antepartum preeclampsia has been shown to decrease some severe maternal outcomes. Conversely, women with de novo postpartum hypertensive disorders remain among the highest risk for severe maternal morbidity due to decreased surveillance and lack of data regarding preventive therapies and interventions. Evidence from multiple randomized controlled trials have demonstrated a benefit in the use of oral loop-diuretics in decreasing postpartum systolic blood pressure, promoting faster normalization of blood pressure, and decreasing the need for antihypertensive therapy in women with an antenatal diagnosis of preeclampsia. Biological plausibility suggests that loop-diuretic therapy may similarly mitigate the normal physiologic mechanism that has been implicated in the pathogenesis of hypertensive complications after delivery in women at risk for de novo postpartum hypertension.

This study is a double-blind randomized placebo-controlled trial of 82 high-risk women to assess whether treatment with oral Lasix (furosemide) after delivery reduces blood pressure at the time of discharge. Women at high risk for de novo postpartum hypertension will be randomized to a five-day course of either 20 mg oral Lasix (furosemide) or placebo once daily initiated after delivery. Women will be monitored through their routine 2-week and 6-week postpartum visits, during which times hypertensive complications and adverse effects of therapy will be assessed.

Inclusion criteria

• Postpartum women
• No antenatal diagnosis of hypertensive disorder of pregnancy at the time of admission for delivery, defined as existing chronic hypertension diagnosis or documented blood pressure of ≥140 systolic OR ≥90 diastolic on at least 2 occasions at least 4 hours apart prior to delivery admission who do not go on to get magnesium for seizure prophylaxis by the time of delivery
• At least 18 years of age
• English or Spanish speakers
• One or more high risk factors for development of de novo postpartum hypertension

Exclusion criteria

• Non-English or Spanish speakers
• Women with a contraindication to diuretic therapy
• Women who have used diuretics in the two weeks prior to delivery