Lack of consistency in research papers over the definition of pre-eclampsia

Gestational Hypertensive Disorders and Maternal Breast Cancer Risk in a Nationwide Cohort of 40,720 Parous Women

BACKGROUND

Preeclampsia and gestational hypertension are hypothesized to be associated with reduced maternal breast cancer risk, but the epidemiologic evidence is inconclusive. Our objective was to examine associations between gestational hypertensive disorders and breast cancer in a nationwide cohort of women with a family history of breast cancer.

METHODS

Women ages 35-74 years who had a sister previously diagnosed with breast cancer, but had never had breast cancer themselves, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported diagnoses of eclampsia, preeclampsia, or gestational hypertension in each pregnancy. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between history of a gestational hypertensive disorder and incident invasive breast cancer or ductal carcinoma in situ among 40,720 parous women. We used age as the time scale and adjusted for birth cohort, race-ethnicity, and reproductive, socioeconomic, and behavioral factors. We examined effect measure modification by risk factors for gestational hypertensive disease and breast cancer and assessed possible etiologic heterogeneity across tumor characteristics.

RESULTS

The prevalence of gestational hypertensive disease was 12%. During follow-up (mean = 10.9 years), 3,198 eligible women self-reported a breast cancer diagnosis. History of a gestational hypertensive disorder was not associated with breast cancer risk (HR = 1.0; 95% CI = 0.90, 1.1). We did not observe clear evidence of effect measure modification or etiologic heterogeneity.

CONCLUSIONS

History of a gestational hypertensive disorder was not associated with breast cancer risk in a cohort of women with a first-degree family history of breast cancer.

The impact of the definition of preeclampsia on disease diagnosis and outcomes: a retrospective cohort study

BACKGROUND

The diagnostic criteria for preeclampsia have evolved from the traditional definition of de novo hypertension and proteinuria to a broader definition of hypertension with evidence of end-organ dysfunction. Although this change is endorsed by various societies such as the International Society for the Study of Hypertension in Pregnancy and the American College of Obstetricians and Gynecologists, there remains controversy with regard to the implementation of broader definitions and the most appropriate definition of end-organ dysfunction.

OBJECTIVE

This study aimed to assess the impact of different diagnostic criteria for preeclampsia on rates of disease diagnosis, disease severity, and adverse outcomes and to identify associations between each component of the different diagnostic criteria and adverse pregnancy outcomes.

STUDY DESIGN

We performed a retrospective cohort study of singleton pregnancies at Monash Health between January 1, 2016 and July 31, 2018. Within this population, all cases of gestational hypertension and preeclampsia were reclassified according to the International Society for the Study of Hypertension in Pregnancy 2001, American College of Obstetricians and Gynecologists 2018, and International Society for the Study of Hypertension in Pregnancy 2018 criteria. Differences in incidence of preeclampsia and maternal and perinatal outcomes were compared between the International Society for the Study of Hypertension in Pregnancy 2001 group and the extra cases identified by American College of Obstetricians and Gynecologists 2018 and International Society for the Study of Hypertension in Pregnancy 2018. Outcomes assessed included biochemical markers of preeclampsia, a composite of adverse maternal outcomes, and a composite of adverse perinatal outcomes. Multiple logistic regression analysis was also performed to assess each component of the American College of Obstetricians and Gynecologists 2018 and International Society for the Study of Hypertension in Pregnancy 2018 criteria and their associations with adverse maternal and perinatal outcomes.

RESULTS

Of 22,094 pregnancies, 751 (3.4%) women had preeclampsia as defined by any of the 3 criteria. Compared with International Society for the Study of Hypertension in Pregnancy 2001, the American College of Obstetricians and Gynecologists 2018 criteria identified an extra 42 women (n=654 vs n=696, 6.4% relative increase) with preeclampsia, and International Society for the Study of Hypertension in Pregnancy 2018 identified an extra 97 women (n=654 vs n=751, 14.8% relative increase). The additional women identified by International Society for the Study of Hypertension in Pregnancy 2018 exhibited a milder form of disease with lower rates of severe hypertension (62.4% vs 44.3%; P<.01) and magnesium sulfate use (11.9% vs 4.1%; P<.05) and a trend toward lower rates of adverse maternal outcomes (9.8% vs 4.1%). These women also delivered at a later gestation, and their babies had a lower number of neonatal intensive care unit admissions and adverse perinatal outcomes. Objective features such as fetal growth restriction, thrombocytopenia, renal and liver impairment, and proteinuria were associated with an increased risk of adverse maternal and perinatal outcomes, whereas subjective neurologic features demonstrated poorer associations.

CONCLUSION

Implementation of broader definitions of preeclampsia will result in an increased incidence of disease diagnosis. However, because women who exclusively fulfill the new criteria have a milder phenotype of the disease, it remains uncertain whether this will translate to improved outcomes.

Hypertension in pregnancy: Pathophysiology and treatment

Hypertensive disorders of pregnancy, an umbrella term that includes preexisting and gestational hypertension, preeclampsia, and eclampsia, complicate up to 10% of pregnancies and represent a significant cause of maternal and perinatal morbidity and mortality. Despite the differences in guidelines, there appears to be consensus that severe hypertension and non-severe hypertension with evidence of end-organ damage need to be controlled; yet the ideal target ranges below 160/110 mmHg remain a source of debate. This review outlines the definition, pathophysiology, goals of therapy, and treatment agents used in hypertensive disorders of pregnancy.

Pre-pregnancy counselling for women with chronic kidney disease: a retrospective analysis of nine years' experience

Background

Women with chronic kidney disease have an increased risk of maternal and fetal complications in pregnancy. Pre-pregnancy counselling is recommended but the format of the counselling process and the experience of the patient have never been assessed. This study examines the experience of women with chronic kidney disease attending pre-pregnancy counselling and evaluates their pregnancy outcomes.

Methods

This is a cross-sectional assessment of 179 women with chronic kidney disease attending a pre-pregnancy counselling clinic (2003–2011) with retrospective evaluation of aetiology, comorbidity, treatment and adverse pregnancy outcome compared with 277 hospital controls. It includes an analysis of descriptive data and free text content from 72 questionnaire responders.

Results

65/72 (90%) of women found the clinic informative. 66 women (92%) felt that the consultation had helped them decide about pursuing pregnancy. 12 women (17%) found the multidisciplinary process intimidating. Free text comments supported the positive nature of the counselling experience, but also highlighted issues of access and emotional impact. Adverse pregnancy outcome rates were significantly higher in women with chronic kidney disease: 7/35 (20%) had pre-eclampsia (p < 0.001), 8/35 (23%) infants were small for gestational age (p < 0.001), 11/35 (31%) had preterm deliveries (<37 weeks) (p < 0.001) and 5/35 (14%) had a pregnancy loss compared with 4%, 10%, 8% and 3% of controls respectively.

Conclusions

Women with a diverse range of renal disease severity and complexity attend pre-pregnancy counselling. Factors affecting pregnancy include hypertension, proteinuria and teratogenic medication. It is important to be able to inform women of the risks to them and their babies before pregnancy in order to facilitate informed-decision making. Most women with chronic kidney disease attending a pre-pregnancy counselling clinic report a positive experience.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0024-6) contains supplementary material, which is available to authorized users.

Validity of pre-eclampsia registration in the medical birth registry of norway for women participating in the norwegian mother and child cohort study, 1999-2010

BACKGROUND

The Norwegian Mother and Child Cohort Study (MoBa), a prospective population-based pregnancy cohort, is a valuable database for studying causes of pre-eclampsia. Pre-eclampsia data in MoBa come from the Medical Birth Registry of Norway (MBRN); thus, we wanted to study the validity of MBRN pre-eclampsia registration for MoBa women.

METHODS

We selected all MoBa pregnancies with pre-eclampsia registered in the MBRN (n = 4081) and a random control group (n = 2000) without pre-eclampsia registrations. After excluding two delivery units not participating in MoBa and one no longer operating, units were asked to provide copies of antenatal charts with blood pressure and urinary measurements from all antenatal visits during pregnancy, and hospital discharge codes from the delivery stay. We received data for 5340 pregnancies delivered 1999-2010 (87% of all eligible). We calculated positive predictive value (PPV), and sensitivity and specificity of MBRN registration, using hypertension and proteinuria on the antenatal charts and/or hospital discharge codes indicating pre-eclampsia as gold standard.

RESULTS

Overall PPV was 83.9% [95% CI 82.7, 85.1] and was higher when women were primiparous, or delivered preterm or low birthweight infants. Severe pre-eclampsia in the MBRN was found to be a true severe pre-eclampsia in 70% of cases. Extrapolating to the total MoBa population, the estimated sensitivity was low - 43.0% (38.7, 48.2) - while specificity was high - 99.2% (99.2, 99.3). False negative cases seemed to have mild forms of pre-eclampsia.

CONCLUSIONS

PPV and specificity of pre-eclampsia registration in the MBRN during 1999-2010 was satisfactory, while sensitivity was low.

Chronic hypertension and pregnancy outcomes: systematic review and meta-analysis

OBJECTIVE

To provide an accurate assessment of complications of pregnancy in women with chronic hypertension, including comparison with population pregnancy data (US) to inform pre-pregnancy and antenatal management strategies.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, Medline, and Web of Science were searched without language restrictions, from first publication until June 2013; the bibliographies of relevant articles and reviews were hand searched for additional reports.

STUDY SELECTION

Studies involving pregnant women with chronic hypertension, including retrospective and prospective cohorts, population studies, and appropriate arms of randomised controlled trials, were included.

DATA EXTRACTION

Pooled incidence for each pregnancy outcome was reported and, for US studies, compared with US general population incidence from the National Vital Statistics Report (2006).

RESULTS

55 eligible studies were identified, encompassing 795,221 pregnancies. Women with chronic hypertension had high pooled incidences of superimposed pre-eclampsia (25.9%, 95% confidence interval 21.0% to 31.5 %), caesarean section (41.4%, 35.5% to 47.7%), preterm delivery <37 weeks' gestation (28.1% (22.6 to 34.4%), birth weight <2500 g (16.9%, 13.1% to 21.5%), neonatal unit admission (20.5%, 15.7% to 26.4%), and perinatal death (4.0%, 2.9% to 5.4%). However, considerable heterogeneity existed in the reported incidence of all outcomes (τ(2)=0.286-0.766), with a substantial range of incidences in individual studies around these averages; additional meta-regression did not identify any influential demographic factors. The incidences (the meta-analysis average from US studies) of adverse outcomes in women with chronic hypertension were compared with women from the US national population dataset and showed higher risks in those with chronic hypertension: relative risks were 7.7 (95% confidence interval 5.7 to 10.1) for superimposed pre-eclampsia compared with pre-eclampsia, 1.3 (1.1 to 1.5) for caesarean section, 2.7 (1.9 to 3.6) for preterm delivery <37 weeks' gestation, 2.7 (1.9 to 3.8) for birth weight <2500 g, 3.2 (2.2 to 4.4) for neonatal unit admission, and 4.2 (2.7 to 6.5) for perinatal death.

CONCLUSIONS

This systematic review, reporting meta-analysed data from studies of pregnant women with chronic hypertension, shows that adverse outcomes of pregnancy are common and emphasises a need for heightened antenatal surveillance. A consistent strategy to study women with chronic hypertension is needed, as previous study designs have been diverse. These findings should inform counselling and contribute to optimisation of maternal health, drug treatment, and pre-pregnancy management in women affected by chronic hypertension.

How placental growth factor detection might improve diagnosis and management of pre-eclampsia

Pre-eclampsia complicates around 5% of pregnancies and hypertensive disorders of pregnancy are responsible for over 60,000 maternal deaths worldwide annually. Identifying women with pre-eclampsia is a major goal of antenatal care in order to target increased surveillance, allow stabilizing therapies to be implemented and to enable timely delivery. Current risk assessment is based on clinical history, imperfect assessment of clinical signs (e.g., hypertension and proteinuria) and nonspecific biochemical markers, all of which are subject to considerable error. This is further confounded by underlying maternal disease such as chronic hypertension or renal pathology. Angiogenic factors reflect the underlying pathophysiology of pre-eclampsia and there is emerging evidence that they can now be used for more accurate risk assessment. The most promising of these factors include placental growth factor and soluble fms-like tyrosine kinase-1. Used at point of care, these can accurately discriminate true disease in suspected cases and subsequent need for delivery.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild to moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve the outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2013) and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy defined, whenever possible, as systolic blood pressure 140 to 169 mmHg and diastolic blood pressure 90 to 109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data.

MAIN RESULTS

Forty-nine trials (4723 women) were included. Twenty-nine trials compared an antihypertensive drug with placebo/no antihypertensive drug (3350 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) (20 trials, 2558 women; risk ratio (RR) 0.49; 95% confidence interval (CI) 0.40 to 0.60; risk difference (RD) -0.10 (-0.13 to -0.07); number needed to treat to harm (NNTH) 10 (8 to 13)) but little evidence of a difference in the risk of pre-eclampsia (23 trials, 2851 women; RR 0.93; 95% CI 0.80 to 1.08). Similarly, there is no clear effect on the risk of the baby dying (27 trials, 3230 women; RR 0.71; 95% CI 0.49 to 1.02), preterm birth (15 trials, 2141 women; RR 0.96; 95% CI 0.85 to 1.10), or small-for-gestational-age babies (20 trials, 2586 women; RR 0.97; 95% CI 0.80 to 1.17). There were no clear differences in any other outcomes.Twenty-two trials (1723 women) compared one antihypertensive drug with another. Alternative drugs seem better than methyldopa for reducing the risk of severe hypertension (11 trials, 638 women; RR (random-effects) 0.54; 95% CI 0.30 to 0.95; RD -0.11 (-0.20 to -0.02); NNTH 7 (5 to 69)). There is also a reduction in the overall risk of developing proteinuria/pre-eclampsia when beta blockers and calcium channel blockers considered together are compared with methyldopa (11 trials, 997 women; RR 0.73; 95% CI 0.54 to 0.99). However, the effect on both severe hypertension and proteinuria is not seen in the individual drugs. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

AUTHORS' CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild to moderate hypertension during pregnancy is worthwhile.

Perinatal and infant mortality in term and preterm births among women with type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to estimate the risks of adverse birth outcomes such as stillbirth, infant death, preterm birth and pre-eclampsia in women with type 1 diabetes, compared with the background population. We further aimed to explore the risks of adverse birth outcomes in preterm and term deliveries separately.

METHODS

By linkage of two nationwide registries, the Medical Birth Registry of Norway and the Norwegian Childhood Diabetes Registry, we identified 1,307 births among women with pregestational type 1 diabetes registered in the Diabetes Registry, and 1,161,092 births in the background population during the period 1985-2004. The ORs with 95% CIs for adverse outcome among women with type 1 diabetes vs the background population were estimated using logistic regression.

RESULTS

The OR for stillbirth (≥22 weeks of gestation) was 3.6 (95% CI 2.5, 5.3), and for perinatal death (stillbirth or death in the first week of life) it was 2.9 (95% CI 2.0, 4.1). The OR for infant death (first year of life) was 1.9 (95% CI 1.1, 3.2). For preterm birth (< 37 weeks of gestation) and pre-eclampsia the ORs were 4.9 (95% CI 4.3, 5.5) and 6.3 (95% CI 5.5, 7.2), respectively. When preterm and term deliveries were analysed separately, the excess risk of stillbirth and infant death in women with diabetes was confined to term deliveries.

CONCLUSIONS/INTERPRETATION

Pregestational type 1 diabetes was associated with a considerably higher risk of adverse pregnancy outcomes, including infant death, compared with the background population. A novel finding of the study was that the increased risk was confined to term births.

Adverse maternal and perinatal outcomes in women with previous preeclampsia: a prospective study

OBJECTIVE

The purpose of this study was to assess recurrence rates of preeclampsia and neonatal outcomes in women with a history of preeclampsia that required preterm delivery.

STUDY DESIGN

Five hundred women with previous preeclampsia that required delivery at <37 weeks' gestation were followed prospectively.

RESULTS

Preeclampsia reoccurred in 117 women (23%). Predictive factors included black (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.16-4.53) or Asian (OR, 2.98; 95% CI, 1.33-6.59) ethnicity, enrollment systolic blood pressure of >130 mm Hg (OR, 2.89; 95% CI, 1.52-5.50), current antihypertensive use (OR, 6.39; 95% CI, 2.38-17.16), and proteinuria of ≥2+ on enrollment urinalysis (OR, 12.35; 95% CI, 3.45-44.21). Women who previously delivered at <34 weeks' gestation were more likely to deliver preterm again (29% vs 17%; relative risk, 1.69; 95% CI, 1.19-2.40) than were those women with previous delivery between 34 and 37 weeks' gestation.

CONCLUSION

Although this study confirms that women with previous preeclampsia that required early delivery are at high risk of the development of preeclampsia, the study identifies risk factors for recurrence and illustrates that women with previous preeclampsia are at greater risk of adverse neonatal outcome.

Pregnancy outcome in women with chronic kidney disease: a prospective cohort study

OBJECTIVE

To evaluate pregnancy outcome in women with chronic kidney disease (CKD) or proteinuria in early pregnancy with concomitant risk for preeclampsia (PE).

METHODS

Thirty-six women with CKD (Cr > 100 μmol/L at booking or Cr > 125 μmol/L prepregnancy or proteinuria ≥ 500 mg/24 hours at booking) and 30 women with proteinuria (≥2+) and known clinical risk for PE were enrolled at 14(+0) to 21(+6) weeks. Pregnancy outcomes were assessed.

RESULTS

Women with mild CKD (prepregnancy Cr < 125 µmol/Cr > 100 µmol at booking; n = 22) had high rates of preeclampsia (40%), preterm delivery (<37 weeks' gestation; 54%), SGA infants (<10th adjusted centile; 64%)and perinatal death (5%). Women with moderate/severe CKD (prepregnancy creatinine > 125 µmol; n = 14) had poor perinatal outcomes: preterm delivery (86%) and perinatal death (14%). Women with proteinuria (≥2+) and concomitant risk of PE also had high rates of pre-eclampsia (60%), preterm delivery (40%), and SGA infants (27%).

CONCLUSIONS

Pregnancy complications for women with CKD remain high. Women with risk factors for PE with proteinuria (≥2+) at booking are also high-risk.

A Prospective Study of the Impact of Automated Dipstick Urinalysis on the Diagnosis of Preeclampsia

OBJECTIVE

To determine prospectively in hypertensive pregnant women 1) the accuracy of dipstick testing for proteinuria using automated urinalysis, 2) factors that might affect such accuracy, and 3) the potential impact of automated dipstick testing on the accuracy of diagnosis of preeclampsia according to acceptance of proteinuria at either 1 + or 2 + level.

DESIGN

Prospective study.

SETTING

Antenatal day assessment unit and antenatal ward of St George Hospital, a teaching hospital in Sydney, Australia.

POPULATION

170 hypertensive pregnant women attending as outpatients or inpatients.

METHODS

503 midstream urine samples were collected prospectively on separate occasions from 170 women. Full urinalysis was recorded using the Bayer Clinitek 50 automated urinalysis device and Multistix 10SG urinalysis strips (Bayer Diagnostics, Victoria, Australia). Each MSU was analysed for spot protein/creatinine ratio and also for culture and sensitivity if symptoms of a urinary tract infection were present or dipstick included positive nitrites. Urinalysis protein results were compared with spot urinary protein/creatinine ratio (previously shown to correlate with 24-hr urine protein excretion) to determine the accuracy of urinalysis. True proteinuria was defined as a ratio >/= 30 mg protein/mmol creatinine.

RESULTS

False positive dipstick tests ranged from 7% at 3 + level to 71% at 1 + proteinuria level while false negative rates were 7% for "nil" and 14% for "trace" proteinuria, 9% overall. Accepting the dipstick proteinuria result at face value led to an incorrect diagnosis of preeclampsia or gestational hypertension in 85 (50%) women. Dipstick proteinuria was significantly more likely to be correct (true positive/true negative) if diastolic blood pressure was elevated > 90 mmHg (p = 0.032) and in the absence of ketonuria (p = 0.001). Accepting a diagnosis of preeclampsia on the basis of de novo hypertension and dipstick testing alone was accurate less often (70%) when > 1 + was used as a discriminant value than at the 82% of presentations when > 2 + was used (p = 0.001).

CONCLUSION

Accepting "nil" or "trace" proteinuria as a true negative dipstick results fails to identify approximately 1 in 11 hypertensive pregnant women with true proteinuria, a false negative rate that may be acceptable provided these women are subject to ongoing vigilant clinical review. Even with automated urinalysis the false positive rate for dipstick levels >/= 1 + is very high, particularly in the presence of ketonuria and relying on this alone to diagnose preeclampsia leads to significant errors in diagnosis. Accepting >/= 2 + dipstick proteinuria improves overall diagnostic accuracy for preeclampsia at the expense of a higher false negative rate. This study emphasizes the need to confirm dipstick proteinuria with a further test such as a spot urine protein/creatinine ratio in all hypertensive pregnant women, particularly in research studies.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild to moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2005, Issue 3), MEDLINE (1966 to November 2005), LILACS (1984 to November 2005) and EMBASE (1974 to November 2005).

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy defined, whenever possible, as systolic blood pressure 140 to 169 mmHg and diastolic blood pressure 90 to 109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data.

MAIN RESULTS

Forty-six trials (4282 women) were included. Twenty-eight trials compared an antihypertensive drug with placebo/no antihypertensive drug (3200 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) (19 trials, 2409 women; relative risk (RR) 0.50; 95% confidence interval (CI) 0.41 to 0.61; risk difference (RD) -0.10 (-0.12 to -0.07); number needed to treat (NNT) 10 (8 to 13)) but little evidence of a difference in the risk of pre-eclampsia (22 trials, 2702 women; RR 0.97; 95% CI 0.83 to 1.13). Similarly, there is no clear effect on the risk of the baby dying (26 trials, 3081 women; RR 0.73; 95% CI 0.50 to 1.08), preterm birth (14 trials, 1992 women; RR 1.02; 95 % CI 0.89 to 1.16), or small-for-gestational-age babies (19 trials, 2437 women; RR 1.04; 95 % CI 0.84 to 1.27). There were no clear differences in any other outcomes. Nineteen trials (1282 women) compared one antihypertensive drug with another. Beta blockers seem better than methyldopa for reducing the risk of severe hypertension (10 trials, 539 women, RR 0.75 (95 % CI 0.59 to 0.94); RD -0.08 (-0.14 to 0.02); NNT 12 (6 to 275)). There is no clear difference between any of the alternative drugs in the risk of developing proteinuria/pre-eclampsia. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

AUTHORS' CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild to moderate hypertension during pregnancy is worthwhile.

Accuracy of urinalysis dipstick techniques in predicting significant proteinuria in pregnancy

OBJECTIVE

To estimate the accuracy of point-of-care dipstick urinalysis in predicting significant proteinuria in pregnancy.

DATA SOURCES

Literature from 1970 to February 2002 was identified via 1). general bibliographic databases, that is, MEDLINE and EMBASE, 2). Cochrane Library and relevant specialist register of the Cochrane Collaboration, and 3). checking the reference lists of known primary and review articles.

METHODS OF STUDY SELECTION

Studies were selected if the accuracy of dipstick urinalysis techniques in predicting total protein excretion was estimated compared with a reference standard (laboratory estimation of protein excretion). The tests included visually read color-change dipsticks and automated dipstick urinalysis. Study selection, quality assessment, and data abstraction were performed independently and in duplicate.

TABULATION, INTEGRATION, AND RESULTS

Data from selected studies were abstracted as 2 x 2 tables comparing the test result with the reference standard. Test accuracy was expressed as likelihood ratios. Summary likelihood ratios were generated as measures of diagnostic accuracy to determine posttest probabilities. The electronic search produced 1543 citations. After independent review of published articles, a total of 34 articles was obtained for further scrutiny, and 7 studies were considered eligible for inclusion in the review. The 6 studies evaluating visual dipstick urinalysis produced a pooled positive likelihood ratio of 3.48 (95% confidence interval 1.66, 7.27) and a pooled negative likelihood ratio of 0.6 (95% confidence interval 0.45, 0.8) for predicting 300 mg/24-hour proteinuria at the 1+ or greater threshold.

CONCLUSION

The accuracy of dipstick urinalysis with a 1+ threshold in the prediction of significant proteinuria is poor and therefore of limited usefulness to the clinician. Accuracy may be improved at higher thresholds (greater than 1+ proteinuria), but available data are sparse and of poor methodological quality. Therefore, it is not possible to make meaningful inferences about accuracy at higher urine dipstick thresholds. There is an urgent need for research in this area of common obstetric practice.

TGF-beta 3 expression during umbilical cord development and its alteration in pre-eclampsia

Members of the TGF-beta family have been shown to play an important role in numerous tissues during development. In the present study we have investigated the spatial and temporal expression of TGF-beta 3, in human umbilical cord development. Total TGF-beta 3 protein content, assessed by immunoblotting, increased with advancing gestation as did immunostaining and mRNA in Wharton's jelly fibroblasts. Immunohistochemical analysis revealed that TGF-beta 3 was present in all cell types. Temporal changes in TGF-beta 3 expression were observed in the vascular smooth muscle cells, such that with advancing gestation TGF-beta 3 protein expression and became mostly restricted to the extracellular compartment of the vascular media. This was associated with a decrease in TGF-beta 3 mRNA expression in umbilical vascular smooth muscle cells. Of clinical significance, umbilical cords from pregnancies complicated by pre-eclampsia, showed a significant reduction in total TGF-beta 3 protein expression when compared to those of age-matched patients. Both TGF-beta 3 mRNA and protein expression were downregulated in the endothelium and smooth muscle layers of the umbilical arteries, as well as in the Wharton jelly fibroblasts. Our data demonstrate that during umbilical cord development TGF-beta 3 expression is spatially and temporally regulated and that TGF-beta 3 expression is altered in umbilical cords of pregnancies complicated by pre-eclampsia. We speculate that the downregulation of TGF-beta 3 expression found in pre-eclamptic umbilical cord may contribute to the abnormal structure and mechanical properties seen in these pathological umbilical cords.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild-moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH STRATEGY

Relevant trials were identified in the register of trials maintained by the Cochrane Pregnancy and Childbirth Group. In addition, the Cochrane Controlled Trial Register, MEDLINE, and EMBASE were searched. Date of last search: October 2000.

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy, defined whenever possible as systolic blood pressure 140-169 mmHg and diastolic blood pressure 90-109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers.

MAIN RESULTS

Overall, this review includes 40 studies (3797 women), 24 of which compared an antihypertensive drug with placebo/no antihypertensive drug (2815 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) [17 trials, 2155 women; relative risk (RR) 0.52 (95% confidence interval (CI) 0.41 to 0.64); risk difference (RD) -0.09 (-0.12 to -0.06); number needed to treat (NNT) 12 (9 to 17)] but little evidence of a difference in the risk of pre-eclampsia [19 trials, 2402 women; RR 0.99 (0.84 to 1.18)]. Similarly, there is no clear effect on the risk of the baby dying [23 trials, 2727 women; RR 0.71(0.46 to 1.09)], preterm birth [12 trials, 1738 women; RR 0.98 (0.85 to 1.13)], or small for gestational age babies [17 trials, 2159 women; RR 1.13 (0.91 to 1.42)]. There were no clear differences in any other outcomes. Seventeen trials (1182 women) compared one antihypertensive drug with another. There is no clear difference between any of these drugs in the risk of developing severe hypertension, and proteinuria/pre-eclampsia. Other antihypertensive agents seem better than methyldopa for reducing the risk of the baby dying [14 trials, 1010 subjects, RR 0.49 (0.24 to 0.99); RD -0.02 (-0.04 to 0.00); NNT 45 (22 to 1341)]. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

REVIEWER'S CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild-moderate hypertension during pregnancy is worthwhile.

How effective is antenatal care in preventing maternal mortality and serious morbidity? An overview of the evidence

This is an overview of evidence of the effectiveness of antenatal care in relation to maternal mortality and serious morbidity, focused in particular on developing countries. It concentrates on the major causes of maternal mortality, and traces their antecedent morbidities and risk factors in pregnancy. It also includes interventions aimed at preventing, detecting or treating any stage along this pathway during pregnancy. This is an updated and expanded version of a review first published by the World Health Organization (WHO) in 1992. The scientific evidence from randomised controlled trials and other types of intervention or observational study on the effectiveness of these interventions is reviewed critically. The sources and quality of available data, and possible biases in their collection or interpretation are considered. As in other areas of maternal health, good-quality evidence is scarce and, just as in many aspects of health care generally, there are interventions in current practice that have not been subjected to rigorous evaluation. A table of antenatal interventions of proven effectiveness in conditions that can lead to maternal mortality or serious morbidity is presented. Interventions for which there is some promising evidence, short of proof, of effectiveness are explored, and the outstanding questions formulated. These are presented in a series of tables with suggestions about the types of study needed to answer them.