2014 年 2 巻 1 号 p. 16-20
Aim: Our aim was to establish a therapeutic strategy for eclampsia, stroke, and hypertension during pregnancy in Japan.
Methods: A questionnaire survey was sent to all obstetric institutions in Aichi Prefecture in order to collect information on characteristics of eclampsia and stroke during pregnancy as well as management of hypertension during labor and puerperium from 2005 to 2012.
Results: Of 518,024 deliveries, 203 cases of eclampsia (0.04%) and 51 cases of stroke (0.01%) were reported. Roughly 40% of eclampsia and stroke occurred at primary medical institutions, while 26% of strokes occurred at home. Most were managed at intensive medical institutions and 7 stroke patients died. Strokes occurred antepartum (41%), during labor (18%), and postpartum (41%). Most medical institutions measured blood pressure (BP) during labor and puerperium. During labor and puerperium, 15% of institutions allowed the supporting medical staff to decide whether or not the BP values should be reported.
Conclusions: This unique, long-term survey to address eclampsia and pregnancy-associated stroke enabled us to obtain detailed information and assess several issues regarding the maternal transport system, collaboration with neurosurgeons and ambulance services, and BP management during labor and puerperium in Japan.
Eclampsia and stroke during pregnancy are major causes of maternal and neonatal death in many countries.1,2,3) Despite the ubiquity of these conditions and their public health impacts, neither their etiologies nor therapeutic strategies for their treatment have been established. In addition, most incidences of eclampsia and stroke occur during labor and puerperium, and sometimes result in maternal death. The lack of etiological information about eclampsia, stroke, and hypertension around the time of delivery makes it difficult to propose appropriate management strategies.
Previously, we reported our findings from a questionnaire-based study of eclampsia and stroke during pregnancy involving all obstetric institutions in Aichi Prefecture (AICHI DATA).4) Aichi Prefecture comprises 6% of the Japanese population as well as 7% of annual births in Japan. Therefore, AICHI DATA could provide useful etiological information regarding eclampsia and stroke during pregnancy in Japanese mothers. Continued analysis of AICHI DATA has allowed us to obtain additional and significant findings. For the purposes of the present study, the questionnaire results provided information on characteristics of eclampsia and stroke during pregnancy as well as measurement of hypertension during pregnancy and puerperium to establish therapeutic strategies for patients affected by these conditions.
We conducted three questionnaire-based studies of eclampsia and stroke during pregnancy that targeted all obstetric institutions in Aichi Prefecture in 2007 (166 institutions), 2010 (155 institutions), and 2012 (144 institutions). All institutions responded to our questionnaires, which were designed to obtain detailed information about eclampsia and stroke during pregnancy. The present study evaluated the questionnaire results by focusing on characteristics of eclampsia and stroke during pregnancy, as well as measurement of blood pressure (BP) during pregnancy and puerperium.
Financial support was provided by the Perinatal Care Association of the Aichi Prefectural Government.
From 2005 to 2012, 518,024 deliveries were reported in Aichi Prefecture. These included 203 cases of eclampsia (0.04%) and 51 cases of stroke (0.01%). Thirty-eight percent of eclampsia and 39% of strokes occurred at primary medical institutions, while 26% of strokes occurred at home. Most incidences of eclampsia (93%) and all strokes were managed at intensive medical institutions (Table 1).
| Total | Intensive institution | Primary institution | Home | |
|---|---|---|---|---|
| Number of institutions | ||||
| 2007 | 166 | 52 | 114 | – |
| 2012 | 144 | 46 | 98 | – |
| Number of deliveries (%) | 518,024 (100) | 177,900 (34) | 340,124 (66) | – |
| Eclampsia | ||||
| Onset (%) | 203 (100) | 118 (58) | 77 (38) | 8 (4) |
| Managed (%) | 203 (100) | 189 (93) | 14 (7) | 0 (0) |
| Stroke | ||||
| Onset (%) | 51 (100) | 18 (35) | 20 (39) | 13 (26) |
| Managed (%) | 51 (100) | 51 (100) | 0 (0) | 0 (0) |
Eclampsia episodes occurred antepartum (19%), during labor (37%), and postpartum (44%). All patients with eclampsia showed good prognoses except for one patient who suffered a neurologic after-effect (Table 2).
| Total | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | |
|---|---|---|---|---|---|---|---|---|---|
| Delivery | 518,024 | 63,512 | 67,311 | 62,431 | 65,007 | 64,338 | 64,393 | 65,755 | 65,277 |
| Eclampsia | 203 | 25 | 29 | 22 | 31 | 19 | 21 | 26 | 30 |
| Onset time | |||||||||
| Antepartum | 39 (19%) | 3 | 4 | 4 | 7 | 3 | 4 | 7 | 7 |
| During labor | 75 (37%) | 12 | 11 | 6 | 12 | 9 | 5 | 10 | 10 |
| Postpartum | 89 (44%) | 10 | 14 | 12 | 12 | 7 | 12 | 9 | 13 |
| Prognosis | |||||||||
| After-effects (−) | 202 | 24 | 29 | 22 | 31 | 19 | 21 | 26 | 30 |
| After-effects (+) | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Death | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Strokes occurred antepartum (41%), during labor (18%), or postpartum (41%). Seven stroke patients died (3 cerebral hemorrhages, 3 subarachnoid hemorrhages [SAH], and 1 cerebral venous thrombosis), while 15 patients suffered neurologic after-effects (Table 3). Stroke cases included 15 cerebral hemorrhages, 9 SAH, 1 arteriovenous malformation (AVM), 4 moyamoya disease, 14 cerebral infarctions, 3 cerebral venous thromboses, and 3 posterior reversible encephalopathy syndrome (PRES). The majority (78%) of strokes which occurred during labor were cerebral hemorrhages. The most common forms of stroke occurring in puerperium were cerebral hemorrhage (19%), SAH (29%), and cerebral infarction (29%). While cerebral hemorrhage (21%) and SAH (33%) had high mortality, cerebral infarction caused no maternal deaths (Table 4).
| Total | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | |
|---|---|---|---|---|---|---|---|---|---|
| Delivery | 518,024 | 63,512 | 67,311 | 62,431 | 65,007 | 64,338 | 64,393 | 65,755 | 65,277 |
| Stroke | 51 | 2 | 7 | 4 | 4 | 9 | 6 | 10 | 9 |
| Onset time | |||||||||
| Antepartum | 21 (41%) | 0 | 2 | 1 | 1 | 5 | 3 | 6 | 3 |
| During labor | 9 (18%) | 1 | 1 | 0 | 1 | 0 | 2 | 1 | 3 |
| Postpartum | 21 (41%) | 1 | 4 | 3 | 2 | 4 | 1 | 3 | 3 |
| Prognosis | |||||||||
| After-effects (−) | 29 | 0 | 4 | 2 | 3 | 5 | 4 | 6 | 5 |
| After-effects (+) | 15 | 2 | 1 | 1 | 0 | 2 | 2 | 4 | 3 |
| Death | 7 | 0 | 2 | 1 | 1 | 2 | 0 | 0 | 1 |
| Total | CH | SAH | AVM | MD | CI | CVT | PRES | Other | |
|---|---|---|---|---|---|---|---|---|---|
| Stroke | 51 | 15 | 9 | 1 | 4 | 14 | 3 | 3 | 2 |
| Institution of Onset | |||||||||
| Intensive care | 18 | 6 | 3 | 0 | 4 | 1 | 2 | 2 | 0 |
| Primary care | 20 | 8 | 4 | 0 | 0 | 5 | 0 | 1 | 2 |
| Home | 13 | 1 | 2 | 1 | 0 | 8 | 1 | 0 | 0 |
| Onset time | |||||||||
| Antepartum | 21 | 4 | 3 | 1 | 2 | 8 | 1 | 2 | 0 |
| During labor | 9 | 7 | 0 | 0 | 2 | 0 | 0 | 0 | 0 |
| Postpartum | 21 | 4 | 6 | 0 | 0 | 6 | 2 | 1 | 2 |
| Therapy | |||||||||
| Conservative | 37 | 7 | 7 | 1 | 3 | 13 | 2 | 3 | 1 |
| Surgery | 9 | 6 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Prognosis | |||||||||
| After-effects (−) | 29 | 5 | 6 | 0 | 2 | 11 | 1 | 3 | 1 |
| After-effects (+) | 15 | 7 | 0 | 1 | 2 | 3 | 1 | 0 | 1 |
| Death | 7 | 3 | 3 | 0 | 0 | 0 | 1 | 0 | 0 |
CH, cerebral hemorrhaging; SAH, subarachnoid hemorrhaging; AVM, arteriovenous malformation; MD, moyamoya disease; CI, cerebral infarction; CVT, cerebral venous thrombosis; PRES, posterior reversible encephalopathy syndrome.
BP measurements were obtained for all patients during labor at 53% of institutions, while 18% only measured BP for patients who presented with BP values greater than 140/90 mmHg on admission. Institutions that allowed supporting medical staff to decide when to take BP measurements comprised 10%, indicating a decrease from the 14% reported by a previous study in 2010.4) With regard to criteria for reporting BP data to doctors, 9% of institutions reported all data, while 58% only reported BP values greater than 140/90 mmHg. The decision to report these values was left up to supporting medical staff at 15% of institutions, indicating a decrease from the 23% reported by a previous study in 2010.4) These findings revealed that BP measurement strategies during labor were left up to the supporting medical staff at roughly 15% of institutions (Table 5).
| Total | Intensive Institution | Primary Institution | |
|---|---|---|---|
| 144 | 46 | 98 | |
| Measurements taken | |||
| All cases | 76 (53%) | 31 | 45 |
| BP≥140/90 mmHg at admission | 26 (18%) | 5 | 21 |
| Upon doctor request only | 20 (14%) | 6 | 14 |
| Decided by supporting medical staff | 15 (10%) | 4 | 11 |
| None | 0 | 0 | 0 |
| Others | 7 | 0 | 7 |
| Report to doctor | |||
| All cases | 13 (9%) | 0 | 13 |
| BP≥140/90 mmHg | 84 (58%) | 27 | 57 |
| BP≥150/100 mmHg | 20 (14%) | 5 | 15 |
| BP≥160/110 mmHg | 2 (1%) | 1 | 1 |
| Decided by supporting medical staff | 21 (15%) | 12 | 9 |
| Others | 4 | 1 | 3 |
BP, blood pressure.
BP measurements in puerperium were taken for all patients at 88% of institutions. BP data were reported to doctors for all patients at 8% of institutions, 60% only reported BP values greater than 140/90 mmHg, and 15% left reporting decisions to the supporting medical staff (Table 6).
| Total | Intensive institution | Primary institutions | |
|---|---|---|---|
| 144 | 46 | 98 | |
| Measurements taken | |||
| All cases | 126 (88%) | 43 | 83 |
| Upon doctor request only | 12 (8%) | 3 | 9 |
| Decided by supporting medical staff | 2 (1%) | 0 | 2 |
| None | 1 | 0 | 1 |
| Others | 3 | 0 | 3 |
| Number of measurements taken | |||
| 1/day | 69 | 30 | 39 |
| 2/day | 34 | 5 | 29 |
| 3/day | 15 | 3 | 12 |
| Report measurements to doctor | |||
| All cases | 12 (8%) | 0 | 12 |
| BP≥140/90 mmHg | 87 (60%) | 28 | 59 |
| BP≥150/100 mmHg | 16 (11%) | 4 | 12 |
| BP≥160/110 mmHg | 3 (2%) | 2 | 1 |
| Decided by supporting medical staff | 22 (15%) | 12 | 10 |
| Others | 4 | 0 | 4 |
BP, blood pressure.
AICHI DATA is a unique, long-term etiological study of eclampsia and pregnancy-associated stroke in Japan, as it comprises useful information obtained from patients at both primary and intensive medical institutions. Continuous development of “AICHI DATA” has enabled us to obtain more detailed information pertaining to 518,024 deliveries in Aichi Prefecture from 2005 to 2012. Of these, 203 cases of eclampsia (0.04%) and 51 cases of stroke (0.01%) were reported, and correspond to similar rates reported in other countries.1,2,3,5)
Approximately 40% of strokes occurred at primary medical institutions, and 26% of them occurred at home. All strokes were managed at intensive medical institutions. These data highlight the importance of not only appropriate diagnoses at primary medical institutions, but also the establishment of efficient inter-institution transport systems and collaboration with ambulance services, similar to that required for dealing with eclampsia.
More than half of the strokes in our sample population occurred either during labor or postpartum. This also indicates that the prevention of stroke and eclampsia through appropriate antihypertensive management around delivery is important.
In our previous report, 1,013 pregnancy cases were classified into 4 groups: the normotensive group (n=761, 75%), in which systolic BP (SBP) remained below 140 mmHg throughout labor; the mildly hypertensive group (n=186, 18%), in which the maximum SBP during labor ranged from 140/90 mmHg to 160/110 mmHg; the severely hypertensive group (n=50, 5%), in which the maximum SBP during labor ranged from 160/110 mmHg to 180/120 mmHg; and the emergent hypertensive group (n=16, 2%),6,7) in which the maximum SBP during labor was greater than 180 mmHg. Of the 927 cases that displayed normal BP on admission, 129, 28, and 9 cases demonstrated mild hypertension, severe hypertension, and emergent hypertension, respectively, between admission and delivery. We advocate that clinicians should pay attention to the presence of hypertension that occurs for the first time during delivery. In addition, repetitive BP measurements are necessary for the successful management of hypertension during labor.
This study found that BP measurement strategies during labor were left up to the supporting medical staff at roughly 15% of institutions, indicating a decrease from that reported by a previous study in 2010.4) If a patient develops hypertension, the supporting medical staff must report the patient’s BP to a doctor immediately and discuss the necessity of medical intervention.
Tan reported that roughly 10% of maternal deaths in the United Kingdom were due to hypertensive disorders in puerperium.8) Walters reported that BP rose progressively over the first 5 postnatal days, peaking on days 3 to 6 postpartum.9) In this study, 4 of the 7 maternal deaths were due to a stroke occurring in puerperium. Forty-four percent of eclampsia incidences and 41% of strokes occurred in puerperium, indicating the importance of accurate antihypertensive management. However, 15% of institutions left reporting decisions of BP values to the supporting medical staff. Thus, in cases involving postpartum hypertension, the supporting medical staff must report the BP values to a doctor and discuss the necessity of medical intervention.
In this study, 90% of institutions began the use of hypotensors when patient BP reached 160/110 mmHg or lower, while 5% began when systolic BP reached 180 mmHg. The Joint National Committee in America and European Society of Hypertension proposed to reduce BP in patients whose BP is greater than 180/120 mmHg (hypertensive emergencies).10,11)
Home BP measurement (HBPM) is becoming increasingly utilized in many countries and is well accepted by hypertensive patients. The European Society of Hypertension has endorsed the use of HBPM in clinical practice as a useful adjunct to conventional office measurements.12) HBPM may be one available tool that can be used to predict and manage hypertension during pregnancy and puerperium. In this study, 85% of institutions used HBPM as a tool to predict hypertension after discharge (data not shown).
This study also highlighted several issues, including the currently poor state of the intra-institutional maternal transport system, the lack of established criteria for BP reporting around the time of delivery, the availability of HBPM, and the importance of collaborating with ambulance services.
AICHI DATA will be continuously developed in the future, and is anticipated to supply more important and etiological data from Japanese subjects.
This work was supported in part by the Perinatal Care Association of the Aichi Prefectural Government.
None.
