Evidence
This page contains a snapshot of featured content which highlights evidence addressing key clinical questions including areas of uncertainty. Please see the main topic reference list for details of all sources underpinning this topic.
BMJ Best Practice evidence tables
Evidence tables provide easily navigated layers of evidence in the context of specific clinical questions, using GRADE and a BMJ Best Practice Effectiveness rating. Follow the links at the bottom of the table, which go to the related evidence score in the main topic text, providing additional context for the clinical question. Find out more about our evidence tables.
This table is a summary of the analysis reported in a guideline (underpinned by a systematic review) that focuses on the above important clinical question.
Confidence in the evidence is very low or low where GRADE has been performed and there may be no difference in effectiveness between the intervention and comparison for key outcomes. However, this is uncertain and new evidence could change this in the future.
Population: Women with hypertension (systolic blood pressure between 140–159 mmHg and diastolic blood pressure between 90–109 mmHg)
Intervention: Outpatient management
Comparison: Inpatient management or outpatient management with real time clinician notifications
| Outcome | Effectiveness (BMJ rating)? | Confidence in evidence (GRADE)? |
|---|---|---|
Home blood pressure monitoring versus hospital monitoring | ||
Gestational age at birth (weeks) | No statistically significant difference | Very Low |
Mode of birth: spontaneous vaginal birth | No statistically significant difference | Very Low |
Home blood pressure telemonitoring (obstetrician not updated) versus home monitoring (obstetrician updated in real time) ᵃ | ||
Gestational age at birth (weeks) | No statistically significant difference | Low |
Mode of birth: caesarean section | No statistically significant difference | Low |
Home normal activity versus hospital bed rest | ||
Perinatal mortality | No statistically significant difference | Very Low |
Small for gestational age (<10th centile) | No statistically significant difference | Very Low |
Gestational age at birth (weeks) | No statistically significant difference | Moderate |
Preterm birth <37 weeks | Favours comparison | Low |
Preterm birth <34 weeks | No statistically significant difference | Very Low |
Admission to neonatal unit | No statistically significant difference | Very Low |
Severe hypertension (>160/110 mmhg) | Favours comparison | Low |
Progression to pre-eclampsia (proteinuria) | No statistically significant difference | Moderate |
Induction of labour | Favours intervention | Moderate |
Mode of birth: caesarean section | No statistically significant difference | Very Low |
Recommendations as stated in the source guideline Do not routinely admit to hospital women with non-severe gestational hypertension (blood pressure 140/90 to 159/109 mmHg) Do not offer bed rest in hospital as a treatment for gestational hypertensionᵇ.
Note The guideline committee noted that they did not have enough evidence to recommend that either home or hospital blood pressure monitoring should take precedence. ᵃ In both groups, blood pressure monitoring was for 7 days only, after which all women saw an obstetrician. Both groups were also told to contact an obstetrician if their daily urine dipstick showed ≥1+ protein, or if they had abnormal symptoms. Blood pressure results were stored on a central database for the “not updated” group, whereas in the other group an obstetrician was immediately informed if the mean blood pressure was >160/100 mmHg over three successive readings. ᵇ The guideline committee noted that while hospital bed rest was favoured for preterm birth and severe hypertension, but not for induction of labour, the study underpinning the evaluation of this intervention was carried out in Zimbabwe, and employed different standards of maternity care to the UK, making the results difficult to extrapolate. Based on their clinical experience the guideline committee therefore did not think it was necessary to admit women with gestational hypertension for hospital bed rest, and kept the recommendation from the previous version of the guideline.
This evidence table is related to the following section/s:
This table is a summary of the analysis reported in a guideline (underpinned by a systematic review) that focuses on the above important clinical question.
Confidence in the evidence is very low or low where GRADE has been performed and there may be no difference in effectiveness between the intervention and comparison for key outcome. However, this is uncertain and new evidence could change this in the future.
Population: Pregnant women with pre-eclampsia
Intervention: Labetalol
Comparison: Nicardipine, Methyldopa, Hydralazine and Nifedipine
| Outcome | Effectiveness (BMJ rating)? | Confidence in evidence (GRADE)? |
|---|---|---|
Intravenous labetalol versus intravenous nicardipine | ||
Minutes needed to achieve effective control of blood pressure (BP)(follow-up mean 1 hour) | No statistically significant difference | Low |
Labetalol versus methyldopa ᵃ | ||
BP control: Mean Arterial Pressure (follow-up mean 7 days) | Favours intervention | Very Low |
Onset of labour (induction) (follow-up mean 7 days) | No statistically significant difference | Very Low |
Intravenous labetalol versus intravenous hydralazine | ||
Stillbirth (follow-up mean 2 hours) | No statistically significant difference | Very Low |
Neonatal death up to 7 days ᵇ | No statistically significant difference | Very Low |
Small for gestational age | No statistically significant difference | Very Low |
Severe hypertension | No statistically significant difference | Very Low |
Eclampsia | See note ᶜ | Moderate |
Haemolysis, elevated liver enzymes, low platelet count (HELLP) | No statistically significant difference | Very Low |
Placental abruption | No statistically significant difference | Moderate |
Mode of birth (caesarean section) ᵇ | No statistically significant difference | Very Low |
Maternal death | See note ᶜ | Moderate |
Intravenous labetalol versus oral nifedipine | ||
Neonatal mortality | No statistically significant difference | Very Low |
Birth weight | No statistically significant difference | Very Low |
Gestational age at birth (weeks) | No statistically significant difference | Very Low |
Minutes needed to achieve effective control of BP ᵇ | Favours intervention | Very Low |
Eclampsia or HELLP | No statistically significant difference | Very Low |
Recommendations as stated in the source guideline Consider labetalol to treat gestational hypertension. Consider nifedipine for women in whom labetalol is not suitable, and methyldopa if labetalol or nifedipine are not suitable. Base the choice on side-effect profiles, risk (including foetal effects), and the woman's preferences.
Note The guideline categorised studies on ‘acute’ management as those including care of women with sudden, uncontrolled hypertension, very high blood pressure levels, or with acute symptoms of pre-eclampsia (headache, visual disturbance, upper abdominal pain). The guideline committee noted that there was not enough evidence to recommend one treatment over another. ᵃ No route of administration is reported in the guideline or original study for either drug. ᵇ The guideline also reported results for this outcome by gestational age, hypertension status, and setting, which did not affect the overall rating in this table. Please see the guideline evidence document for more details. ᶜ No incidents of this outcome occurred in those who received hydralazine or labetalol.
This evidence table is related to the following section/s:
Cochrane Clinical Answers
Cochrane Clinical Answers (CCAs) provide a readable, digestible, clinically focused entry point to rigorous research from Cochrane systematic reviews. They are designed to be actionable and to inform decision making at the point of care and have been added to relevant sections of the main Best Practice text.
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