Ambulatory versus conventional methods for monitoring blood pressure during pregnancy

Recent advances in the diagnosis and management of pre-eclampsia

Pre-eclampsia is an elusive condition to diagnose and a complex disease to manage. There have been recent developments in prediction, prevention, diagnosis, and management. Risk modelling has been used to identify women at highest risk of developing pre-eclampsia as well as predicting maternal adverse outcomes in confirmed disease. New evidence has shown that aspirin prophylaxis significantly reduces early onset pre-eclampsia as well as preterm birth. The criteria for the diagnosis of pre-eclampsia are evolving, and proteinuria is no longer a pre-requisite to make a diagnosis. Angiogenic biomarker testing accelerates diagnosis as well as minimises adverse maternal outcomes and has been incorporated into national guidelines. Emerging evidence demonstrates that expedited delivery in late preterm pre-eclampsia may be protective against maternal adverse outcomes but increase the risk of neonatal unit admission. Both women and their offspring are at increased risk of long-term health complications following pre-eclampsia, and it is important that postnatal health is optimised. This article summarises recent developments in the field of pre-eclampsia research, evaluating the impact on clinical care for women at risk of, or with suspected or confirmed, pre-eclampsia.

Antenatal interventions for preventing stillbirth, fetal loss and perinatal death: an overview of Cochrane systematic reviews

BACKGROUND

Stillbirth is generally defined as a death prior to birth at or after 22 weeks' gestation. It remains a major public health concern globally. Antenatal interventions may reduce stillbirths and improve maternal and neonatal outcomes in settings with high rates of stillbirth. There are several key antenatal strategies that aim to prevent stillbirth including nutrition, and prevention and management of infections.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on the effects of antenatal interventions for preventing stillbirth for low risk or unselected populations of women.

METHODS

We collaborated with Cochrane Pregnancy and Childbirth's Information Specialist to identify all their published reviews that specified or reported stillbirth; and we searched the Cochrane Database of Systematic Reviews (search date: 29 Feburary 2020) to identify reviews published within other Cochrane groups. The primary outcome measure was stillbirth but in the absence of stillbirth data, we used perinatal mortality (both stillbirth and death in the first week of life), fetal loss or fetal death as outcomes. Two review authors independently evaluated reviews for inclusion, extracted data and assessed quality of evidence using AMSTAR (A Measurement Tool to Assess Reviews) and GRADE tools. We assigned interventions to categories with graphic icons to classify the effectiveness of interventions as: clear evidence of benefit or harm; clear evidence of no effect or equivalence; possible benefit or harm; or unknown benefit or harm or no effect or equivalence.

MAIN RESULTS

We identified 43 Cochrane Reviews that included interventions in pregnant women with the potential for preventing stillbirth; all of the included reviews reported our primary outcome 'stillbirth' or in the absence of stillbirth, 'perinatal death' or 'fetal loss/fetal death'. AMSTAR quality was high in 40 reviews with scores ranging from 8 to 11 and moderate in three reviews with a score of 7. Nutrition interventions Clear evidence of benefit: balanced energy/protein supplementation versus no supplementation suggests a probable reduction in stillbirth (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.39 to 0.94, 5 randomised controlled trials (RCTs), 3408 women; moderate-certainty evidence). Clear evidence of no effect or equivalence for stillbirth or perinatal death: vitamin A alone versus placebo or no treatment; and multiple micronutrients with iron and folic acid versus iron with or without folic acid. Unknown benefit or harm or no effect or equivalence: for all other nutrition interventions examined the effects were uncertain. Prevention and management of infections Possible benefit for fetal loss or death: insecticide-treated anti-malarial nets versus no nets (RR 0.67, 95% CI 0.47 to 0.97, 4 RCTs; low-certainty). Unknown evidence of no effect or equivalence: drugs for preventing malaria (stillbirth RR 1.02, 95% CI 0.76 to 1.36, 5 RCTs, 7130 women, moderate certainty in women of all parity; perinatal death RR 1.24, 95% CI 0.94 to 1.63, 4 RCTs, 5216 women, moderate-certainty in women of all parity). Prevention, detection and management of other morbidities Clear evidence of benefit: the following interventions suggest a reduction: midwife-led models of care in settings where the midwife is the primary healthcare provider particularly for low-risk pregnant women (overall fetal loss/neonatal death reduction RR 0.84, 95% CI 0.71 to 0.99, 13 RCTs, 17,561 women; high-certainty), training versus not training traditional birth attendants in rural populations of low- and middle-income countries (stillbirth reduction odds ratio (OR) 0.69, 95% CI 0.57 to 0.83, 1 RCT, 18,699 women, moderate-certainty; perinatal death reduction OR 0.70, 95% CI 0.59 to 0.83, 1 RCT, 18,699 women, moderate-certainty). Clear evidence of harm: a reduced number of antenatal care visits probably results in an increase in perinatal death (RR 1.14 95% CI 1.00 to 1.31, 5 RCTs, 56,431 women; moderate-certainty evidence). Clear evidence of no effect or equivalence: there was evidence of no effect in the risk of stillbirth/fetal loss or perinatal death for the following interventions and comparisons: psychosocial interventions; and providing case notes to women. Possible benefit: community-based intervention packages (including community support groups/women's groups, community mobilisation and home visitation, or training traditional birth attendants who made home visits) may result in a reduction of stillbirth (RR 0.81, 95% CI 0.73 to 0.91, 15 RCTs, 201,181 women; low-certainty) and perinatal death (RR 0.78, 95% CI 0.70 to 0.86, 17 RCTs, 282,327 women; low-certainty). Unknown benefit or harm or no effect or equivalence: the effects were uncertain for other interventions examined. Screening and management of fetal growth and well-being Clear evidence of benefit: computerised antenatal cardiotocography for assessing infant's well-being in utero compared with traditional antenatal cardiotocography (perinatal mortality reduction RR 0.20, 95% CI 0.04 to 0.88, 2 RCTs, 469 women; moderate-certainty). Unknown benefit or harm or no effect or equivalence: the effects were uncertain for other interventions examined.

AUTHORS' CONCLUSIONS

While most interventions were unable to demonstrate a clear effect in reducing stillbirth or perinatal death, several interventions suggested a clear benefit, such as balanced energy/protein supplements, midwife-led models of care, training versus not training traditional birth attendants, and antenatal cardiotocography. Possible benefits were also observed for insecticide-treated anti-malarial nets and community-based intervention packages, whereas a reduced number of antenatal care visits were shown to be harmful. However, there was variation in the effectiveness of interventions across different settings, indicating the need to carefully understand the context in which these interventions were tested. Further high-quality RCTs are needed to evaluate the effects of antenatal preventive interventions and which approaches are most effective to reduce the risk of stillbirth. Stillbirth (or fetal death), perinatal and neonatal death need to be reported separately in future RCTs of antenatal interventions to allow assessment of different interventions on these rare but important outcomes and they need to clearly define the target populations of women where the intervention is most likely to be of benefit. As the high burden of stillbirths occurs in low- and middle-income countries, further high-quality trials need to be conducted in these settings as a priority.

Setting and techniques for monitoring blood pressure during pregnancy

BACKGROUND

Regular blood pressure (BP) measurement is crucial for the diagnosis and management of hypertensive disorders in pregnancy, such as pre-eclampsia. BP can be measured in various settings, such as conventional clinics or self-measurement at home, and with different techniques, such as using auscultatory or automated BP devices. It is important to understand the impact of different settings and techniques of BP measurement on important outcomes for pregnant women.

OBJECTIVES

To assess the effects of setting and technique of BP measurement for diagnosing hypertensive disorders in pregnancy on subsequent maternal and perinatal outcomes, women's quality of life, or use of health service resources.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) on 22 April 2020, and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving pregnant women, using validated BP devices in different settings or using different techniques.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data, assessed risk of bias, and used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

Of the 21 identified studies, we included three, and excluded 11; seven were ongoing. Of the three included RCTs (536,607 women), one was a cluster-RCT, with a substantially higher number of participants (536,233 deliveries) than the other two trials, but did not provide data for most of our outcomes. We generally judged the included studies at low risk of bias, however, the certainty of the evidence was low, due to indirectness and imprecision. Meta-analysis was not possible because each study investigated a different comparison. None of the included studies reported our primary outcome of systolic BP greater than or equal to 150 mmHg. None of the studies reported any of these important secondary outcomes: antenatal hospital admissions, neonatal unit length of stay, or neonatal endotracheal intubation and use of mechanical ventilation. Setting of BP measurement: self-measurement versus conventional clinic measurement (one study, 154 women) There were no maternal deaths in either the self-monitoring group or the usual care group. The study did not report perinatal mortality. Self-monitoring may lead to slightly more diagnoses of pre-eclampsia compared with usual care (risk ratio (RR) 1.49, 95% confidence interval (CI) 0.87 to 2.54; 154 women; 1 study; low-certainty evidence) but the wide 95% CI is consistent with possible benefit and possible harm. Self-monitoring may have little to no effect on the likelihood of induction of labour compared with usual care (RR 1.09, 95% CI 0.82 to 1.45; 154 women; 1 study; low-certainty evidence). We are uncertain if self-monitoring BP has any effect on maternal admission to intensive care (RR 1.54, 95% CI 0.06 to 37.25; 154 women; 1 study; low-certainty evidence), stillbirth (RR 2.57, 95% CI 0.13 to 52.63; 154 women; 1 study; low-certainty evidence), neonatal death (RR 1.54, 95% CI 0.06 to 37.25; 154 women; 1 study; low-certainty evidence) or preterm birth (RR 1.15, 95% CI 0.37 to 3.55; 154 women; 1 study; low-certainty evidence), compared with usual care because the certainty of evidence is low and the 95% CI is consistent with appreciable harms and appreciable benefits. Self-monitoring may lead to slightly more neonatal unit admissions compared with usual care (RR 1.53, 95% CI 0.65 to 3.62; 154 women; 1 study; low-certainty evidence) but the wide 95% CI includes the possibility of slightly fewer admissions with self-monitoring. Technique of BP measurement: Korotkoff phase IV (K4, muffling sound) versus Korotkoff phase V (K5, disappearance of sound) to represent diastolic BP (one study, 220 women) There were no maternal deaths in either the K4 or K5 group. There may be little to no difference in the diagnosis of pre-eclampsia between using K4 or K5 for diastolic BP (RR 1.16; 95% CI 0.89 to 1.49; 1 study; 220 women; low-certainty evidence), since the wide 95% CI includes the possibility of more diagnoses with K4. We are uncertain if there is a difference in perinatal mortality between the groups because the quality of evidence is low and the 95% CI is consistent with appreciable harm and appreciable benefit (RR 1.14, 95% CI 0.16 to 7.92; 1 study, 220 women; low-certainty evidence). The trial did not report data on maternal admission to intensive care, induction of labour, stillbirth, neonatal death, preterm birth, or neonatal unit admissions. Technique of BP measurement: CRADLE intervention (CRADLE device, a semi-automated BP monitor with additional features, and an education package) versus usual care (one study, 536,233 deliveries) There may be little to no difference between the use of the CRADLE device and usual care in the number of maternal deaths (adjusted RR 0.80, 95% CI 0.30 to 2.11; 536,233 women; 1 study; low-certainty evidence), but the 95% CI is consistent with appreciable harm and appreciable benefit. The trial did not report pre-eclampsia, induction of labour, perinatal mortality, preterm birth, or neonatal unit admissions. Maternal admission to intensive care and perinatal outcomes (stillbirths and neonatal deaths) were only collected for a small proportion of the women, identified by an outcome not by baseline characteristics, thereby breaking the random allocation. Therefore, any differences between the groups could not be attributed to the intervention, and we did not extract data for these outcomes.

AUTHORS' CONCLUSIONS

The benefit, if any, of self-monitoring BP in hypertensive pregnancies remains uncertain, as the evidence is limited to one feasibility study. Current practice of using K5 to measure diastolic BP is supported for women with pregnancy hypertension. The benefit, if any, of using the CRADLE device to measure BP in pregnancy remains uncertain, due to the limitations and instability of the trial study design.

Blood pressure assessments of pregnant women in a Day Assessment Unit - A prospective observational study

Aim

We investigated the optimum time and number of observations for assessing women in the Day Assessment Unit.

Methods

A single centre prospective observational study was undertaken. Women referred for blood pressure assessment in the Day Assessment Unit were recruited.

Results

The blood pressure of women who subsequently developed preeclampsia was noted to change differently over the time of observation compared to women with other hypertensive disorders, most notably in the first and third hour (p = 0.042), although the averages at each hour did not differ between these two groups.

Conclusions

Mean blood pressure measured over four hours did not significantly differ compared to blood pressure measured over one hour. Women who subsequently developed preeclampsia had a different pattern of blood pressure change whilst in the Day Assessment Unit.

Recent advances in the diagnosis and management of pre-eclampsia

Pre-eclampsia is a leading cause of maternal mortality, responsible annually for over 60,000 maternal deaths around the globe. Pre-eclampsia is a multisystem disease featuring hypertension, proteinuria, and renal, hepatic, and neurological involvement. Diagnosis is often elusive, as clinical presentation is highly variable. Even those with severe disease can remain asymptomatic. Angiogenic factors are emerging as having a role in the diagnosis of pre-eclampsia and in prognostication of established disease. In this article, we summarize new developments and focus on angiogenic biomarkers for prediction of disease onset. We also discuss recent advances in management strategies for patients with hypertensive disorders of pregnancy.

Epidural therapy for the treatment of severe pre-eclampsia in non labouring women

BACKGROUND

Pre-eclampsia is a pregnancy-specific multi-organ disorder, which is characterised by hypertension and multisystem organ involvement and which has significant maternal and fetal morbidity and mortality. Failure of the placental vascular remodelling and reduced uteroplacental flow form the etiopathological basis of pre-eclampsia. There are several established therapies for pre-eclampsia including antihypertensives and anticonvulsants. Most of these therapies aim at controlling the blood pressure or preventing complications of elevated blood pressure, or both. Epidural therapy aims at blocking the vasomotor tone of the arteries, thereby increasing uteroplacental blood flow. This review was aimed at evaluating the available evidence about the possible benefits and risks of epidural therapy in the management of severe pre-eclampsia, to define the current evidence level of this therapy, and to determine what (if any) further evidence is required.

OBJECTIVES

To assess the effectiveness, safety and cost of the extended use of epidural therapy for treating severe pre-eclampsia in non-labouring women. This review aims to compare the use of extended epidural therapy with other methods, which include intravenous magnesium sulphate, anticonvulsants other than magnesium sulphate, with or without use of the antihypertensive drugs and adjuncts in the treatment of severe pre-eclampsia.This review only considered the use of epidural anaesthesia in the management of severe pre-eclampsia in the antepartum period and not as pain relief in labour.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (13 July 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing epidural therapy versus traditional therapy for pre-eclampsia in the form of antihypertensives, anticonvulsants, magnesium sulphate, low-dose dopamine, corticosteroids or a combination of these, were eligible for inclusion. Trials using a cluster design, and studies published in abstract form only are also eligible for inclusion in this review. Cross-over trials were not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed trials for inclusion and trial quality. There were no relevant data available for extraction.

MAIN RESULTS

We included one small study (involving 24 women). The study was a single-centre randomised trial conducted in Mexico. This study compared a control group who received antihypertensive therapy, anticonvulsant therapy, plasma expanders, corticosteroids and dypyridamole with an intervention group that received epidural block instead of the antihypertensives, as well as all the other four drugs. Lumbar epidural block was given using 0.25% bupivacaine, 10 mg bolus and 5 mg each hour on continuous epidural infusion for six hours. This study was at low risk of bias in three domains but was assessed to be high risk of bias in two domains due to lack of allocation concealment and blinding of women and staff, and unclear for random sequence generation and outcome assessor blinding.The included study did not report on any of this review's important outcomes. Meta-analysis was not possible.For the mother, these were: maternal death (death during pregnancy or up to 42 days after the end of the pregnancy, or death more than 42 days after the end of the pregnancy); development of eclampsia or recurrence of seizures; stroke; any serious morbidity: defined as at least one of stroke, kidney failure, liver failure, HELLP syndrome (haemolysis, elevated liver enzymes and low platelets), disseminated intravascular coagulation, pulmonary oedema.For the baby, these were: death: stillbirths (death in utero at or after 20 weeks' gestation), perinatal deaths (stillbirths plus deaths in the first week of life), death before discharge from the hospital, neonatal deaths (death within the first 28 days after birth), deaths after the first 28 days; preterm birth (defined as the birth before 37 completed weeks' gestation); and side effects of the intervention. Reported outcomesThe included study only reported on a single secondary outcome of interest to this review: the Apgar score of the baby at birth and after five minutes and there was no clear difference between the intervention and control groups.The included study also reported a reduction in maternal diastolic arterial pressure. However, the change in maternal mean arterial pressure and systolic arterial pressure, which were the other reported outcomes of this trial, were not significantly different between the two groups.

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence from randomised controlled trials to evaluate the effectiveness, safety or cost of using epidural therapy for treating severe pre-eclampsia in non-labouring women.High-quality randomised controlled trials are needed to evaluate the use of epidural agents as therapy for treatment of severe pre-eclampsia. The rationale for the use of epidural is well-founded. However there is insufficient evidence from randomised controlled trials to show that the effect of epidural translates into improved maternal and fetal outcomes. Thus, there is a need for larger, well-designed studies to come to an evidence-based conclusion as to whether the lowering of vasomotor tone by epidural therapy results in better maternal and fetal outcomes and for how long that could be maintained. Another important question that needs to be answered is how long should extended epidural be used to ensure any potential clinical benefits and what could be the associated side effects and costs. Interactions with other modalities of treatment and women's satisfaction could represent other avenues of research.

Aspirin for Prevention of Preeclampsia

Aspirin is currently the most widely prescribed treatment in the prevention of cardiovascular complications. The indications for the use of aspirin during pregnancy are, however, the subject of much controversy. Since the first evidence of the obstetric efficacy of aspirin in 1985, numerous studies have tried to determine the effect of low-dose aspirin on the incidence of preeclampsia, with very controversial results. Large meta-analyses including individual patient data have demonstrated that aspirin is effective in preventing preeclampsia in high-risk patients, mainly those with a history of preeclampsia. However, guidelines regarding the usage of aspirin to prevent preeclampsia differ considerably from one country to another. Screening modalities, target population, and aspirin dosage are still a matter of debate. In this review, we report the pharmacodynamics of aspirin, its main effects according to dosage and gestational age, and the evidence-based indications for primary and secondary prevention of preeclampsia.

The management of hypertension in pregnancy

Hypertensive pregnancy disorders complicate 6% to 8% of pregnancies and cause significant maternal and fetal morbidity and mortality. The goal of treatment is to prevent significant cerebrovascular and cardiovascular events in the mother without compromising fetal well-being. Current guidelines differentiate between the treatment of women with acute hypertensive syndromes of pregnancy and women with preexisting chronic hypertension in pregnancy. This review will address the management of hypertension in pregnancy, review the various pharmacologic therapies, and discuss the future directions in this field.

[Hypertension in pregnancy: the current state of the art]

Hypertension complicates 6-8% of pregnancies and includes the following four conditions: hypertension preceding pregnancy or documented before the 20th week of gestation; pre-eclampsia (PE)/eclampsia; chronic hypertension with superimposed pre-eclampsia; and gestational hypertension. The latter is defined as a significant rise in blood pressure after the 20th week of pregnancy in previously normotensive women, to over 140/90 mmHg. When blood pressure remains above 160/110 mmHg, it is considered severe. PE is defined as the presence of proteinuria (> or = 300 mg/24 h) in pregnant women with hypertension. The hypertensive syndromes of pregnancy are among the leading causes of maternal and fetal morbidity and mortality and anti-hypertensive treatment is part of the therapeutic arsenal used to prevent serious complications. Although the role of utero-placental insufficiency due to deficient migration of trophoblasts to the spiral arteries is universally accepted, the pathophysiology of PE remains largely unknown and is the subject of debate. No effective ways of predicting or preventing PE have been found, which highlights the need for further research in this field. This review aims primarily to evaluate recent advances in our understanding of the pathophysiology of gestational hypertension and especially PE, and new ways of predicting PE. Additionally, we present a brief review on the diagnosis, prevention and treatment of PE.

Twenty-four-hour ambulatory blood pressure monitor heart rate: a potential marker for gestational hypertension in at-risk women

We prospectively correlated the 24-hour ambulatory blood pressure measurements (ABPM) to conventional sphygmomanometer blood pressure measurements (CSM) in women at risk for gestational hypertensive disorders (GHTNDs) and identified predictive factors from ABPM for GHTND. We analyzed 73 women with ≥ 1 risk factor for developing a GHTND. Using both the CSM and ABPM, the systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP), and heart rate (HR) were measured for 24 hours during three periods (14 to 24 weeks; 24 to 32 weeks; and 33 weeks to delivery). Correlation between the CSM and ABPM lessened as pregnancy progressed. Seventeen (25%) of women developed a GHTND. MAP variability increased in the GHTND group versus those without a GHTND. The odds of developing a GHTND increased 1.5 times for every 1 beat per minute increase in the ABPM 24-hour HR at visit 1 and reversed by visit 3. In women at risk for a GHTND, CSM and ABPM correlate less well as pregnancy advances. HR changes in at-risk women may be a marker for the development of a GHTND and may reflect increased sympathetic activity and/or decreased baroreceptor sensitivity.

Blood pressure measurement in pregnancy: the effect of arm circumference and sphygmomanometer cuff size

This study aimed to assess the difference in blood pressure readings between the standard and large cuff and to determine if such a difference applies over a range of arm circumferences (ACs) in pregnancy. We measured blood pressure on 219 antenatal women. Six blood pressure readings were taken, three with a standard 'adult' and three with a 'large' cuff, in random order. A random zero sphygmomanometer was used by a trained observer. Women with an AC >33 cm were similar in age, gestational age and parity but were heavier and had more hypertension than those with AC ≤33 cm. There was a systematic difference between the standard and large cuff of 5-7 mmHg with little effect due to AC. We were unable to demonstrate an association between the standard and large cuff blood pressure difference and increasing blood pressure. Our study has shown that both systolic and diastolic blood pressure measurements are more dependent on the cuff size used than AC and for the individual it is difficult to predict the magnitude of effect the different cuff sizes will have on blood pressure measurements. This study has shown the presence of an average difference in blood pressure measurement between standard and large cuffs in pregnancy, and does not support the arbitrary 33 cm 'cut-off' recommended in guidelines for the use of a large cuff in pregnancy.

A review of the methodological features of systematic reviews in maternal medicine

BACKGROUND

In maternal medicine, research evidence is scattered making it difficult to access information for clinical decision making. Systematic reviews of good methodological quality are essential to provide valid inferences and to produce usable evidence summaries to guide management. This review assesses the methodological features of existing systematic reviews in maternal medicine, comparing Cochrane and non-Cochrane reviews in maternal medicine.

METHODS

Medline, Embase, Database of Reviews of Effectiveness (DARE) and Cochrane Database of Systematic Reviews (CDSR) were searched for relevant reviews published between 2001 and 2006. We selected those reviews in which a minimum of two databases were searched and the primary outcome was related to the maternal condition. The selected reviews were assessed for information on framing of question, literature search and methods of review.

RESULTS

Out of 2846 citations, 68 reviews were selected. Among these, 39 (57%) were Cochrane reviews. Most of the reviews (50/68, 74%) evaluated therapeutic interventions. Overall, 54/68 (79%) addressed a focussed question. Although 64/68 (94%) reviews had a detailed search description, only 17/68 (25%) searched without language restriction. 32/68 (47%) attempted to include unpublished data and 11/68 (16%) assessed for the risk of missing studies quantitatively. The reviews had deficiencies in the assessment of validity of studies and exploration for heterogeneity. When compared to Cochrane reviews, other reviews were significantly inferior in specifying questions (OR 20.3, 95% CI 1.1-381.3, p = 0.04), framing focussed questions (OR 30.9, 95% CI 3.7- 256.2, p = 0.001), use of unpublished data (OR 5.6, 95% CI 1.9-16.4, p = 0.002), assessment for heterogeneity (OR 38.1, 95%CI 2.1, 688.2, p = 0.01) and use of meta-analyses (OR 3.7, 95% CI 1.3-10.8, p = 0.02).

CONCLUSION

This study identifies areas which have a strong influence on maternal morbidity and mortality but lack good quality systematic reviews. Overall quality of the existing systematic reviews was variable. Cochrane reviews were of better quality as compared to other reviews. There is a need for good quality systematic reviews to inform practice in maternal medicine.