Adverse Maternal Consequences Associated with Prolonged Acute-Onset Severe Systolic Hypertension during Pregnancy &Early Postpartum: Pitfalls in Practice &Lessons Learned

OBJECTIVE: To determine the types of major maternal-perinatal morbidity associated with prolonged, acute-onset severe systolic hypertension during pregnancy and postpartum. METHODS: A medicolegal database retaining only medical record data was created from all cases involving women with medical/hypertensive disorders of pregnancy evaluated by the first author between 1986-2015. Case files of women that experienced severe systolic hypertension (SSH) sustained for many hours to days were identified for study. RESULTS: Sixty six pregnant/postpartum women met study criteria. Stroke secondary to intracranial hemorrhage or thrombosis (65.2) and acute pulmonary edema (33%) were the leading causes of maternal morbidity and mortality, most often antepartum as a component of early-onset preeclampsia (≤34 weeks). Eclampsia, abruptio placenta and injury to heart, liver and/or kidneys were other frequent co-morbidities. Seven postpartum women developed sudden new-onset postpartum SSH and suffered a stroke 4 - 13 days after delivery. Maternal mortality (54.6%) and morbidity as persistent disability (24.2%) were high in this cohort. CONCLUSION: Failure to rapidly respond, reduce and sustain at a safe level acute-onset SSH poses a significant threat to the wellbeing of mothers and babies, before and in the weeks following delivery. Systems to implement safe practices to identify and emergently treat severe maternal hypertension are needed.

Management of Hypertension in Pregnancy

Hypertension in pregnancy is currently defined as a systolic blood pressure(BP)of 140 mmHg or more,or a diastolic BP of 90 mmHg or more.This level of BP warrants antihypertensive therapy.Treating to a target BP of 135/85 mmHg halves the risk of severe hypertension that is itself associated with adverse maternal and perinatal outcomes,similar in magnitude to preeclampsia.While based on the results of the Control of Hypertension in Pregnancy Study(CHIPS)trial,this finding is consistent with all antihypertensive trials to date.Also,in the CHIPS trial,“tight”BP control also halved the risk of progression to thrombocytopenia and elevated liver enzymes for the mother,without adverse effects for the fetus or newborn.This was true regardless of the gestational age at which BP control was instituted.While methyldopa,labetalol,and nifedipine are the most commonly-recommended oral antihypertensives,it is not clear that one antihypertensive agent has advantages over the others for treatment of non-severe hypertension in pregnancy.No antihypertensives,including renin-angiotensin-aldosterone system(RAAS)inhibitors,have been shown to be teratogenic,although there may be an increase in malformations associated with the underlying condition of chronic hypertension.Atenolol and RAAS inhibitors should not be used once pregnancy is diagnosed,based on fetotoxicity.At present,BP treatment targets used in clinic are the same as those used at home as the differences are quite variable among hypertensive women.For treatment of acute severe hypertension,the most commonly-recommended antihypertensives are oral nifedipine,IV labetalol,and IV hydralazine,although oral agents have also been shown to be effective in the majority of women;while concerns raised about IV hydralazine-induced maternal hypotension and its consequences have not been confirmed,this medication may be an inferior antihypertensive to oral nifedipine.While treatment recommendations are based on evidence,women should be engaged in decision-making,as their values may alter target BP and antihypertensive choice.Future work will clarify the optimal target BP based on home BP measurements;whether BP targets should be lowered further if the definition of hypertension is based on a lower BP;which,if any,antihypertensive medication for non-severe hypertension is better with regards to maternal and perinatal outcomes;and whether factors beyond BP level(such as variability,race,and other physiological variables)should inform antihypertensive therapy in pregnancy.