A Survey of Canadian Practitioners Regarding Diagnosis and Evaluation of the Hypertensive Disorders of Pregnancy

Management of hypertension in pregnancy: a descriptive report of two clinic practices

Objective: To describe the current clinical practice in the treatment of hypertension in pregnancy.Methods: Retrospective chart review described hypertension treatment of pregnant women in two urban clinics in Minnesota USA, over 27 months. Data elements collected: blood pressure (BP) readings with gestational age, goal BP documented, and pharmacological treatments utilized.Results: Sixty patients had multiple elevated BP readings in prenatal care encounters. Of 60 included patients, 18 were treated with antihypertensives and 11 had documented BP goals. Documented goal BPs varied in numeric goal and some only listed systolic or diastolic goal.Conclusion: Inconsistencies exist in current treatment and documentation of hypertension in pregnancy.

An exploratory study into the role of miR-204-5p in pregnancy-induced hypertension

The molecular mechanism that leads to pregnancy-induced hypertension (PIH), a pregnancy-specific syndrome, remains poorly understood. It has been suggested that microRNAs (miRNAs) may be potentially useful biomarkers for severe preeclampsia (PE), which is an important condition associated with PIH. The aim of the present study was to identify miR-204 by verifying differentially expressed serum miRNAs in patients with PIH during pregnancy compared with normal controls. Subsequently, the effects of miR-204 on proliferation and apoptosis of human choriocarcinoma (JAR) cells in hypoxic microenvironment were investigated. Previous studies indicated a number of miRNA candidates and the present study validated the expression of eight miRNAs in serum samples using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A higher expression of miR-204 was identified in patients with PIH. To assess the impact of miR-204 inhibition on hypoxic JAR cells function in vitro, cell proliferation was detected using a Cell Counting Kit-8 assay. The rate of apoptosis and cell cycle progression was then examined by flow cytometry. RT-qPCR confirmed that serum miR-204-5p is more highly expressed in patients with PIH. Further statistical analysis indicated that the survival ratio of JAR cells in hypoxic microenvironments was increased in the miR-204-5p inhibitor group. However, the miR-204-5p inhibitor protected hypoxic JAR cells from apoptosis. The analysis of cell-cycle status demonstrated that the percentage of cells in the G2/G1 phase was larger compared with the control group. The results of the present study suggest that low levels of miR-204-5p may increase cell proliferation and reduce cell apoptosis with cell cycle changes in vitro. Therefore, serum miR-204-5p may be used as a notable biomarker for the diagnosis, prevention and treatment of PIH.

Antepartum eclampsia <34 weeks case series: advisable to postpone delivery to administer corticosteroids for fetal pulmonary benefit?

OBJECTIVE

To determine if postponement of delivery to administer fetal lung maturation corticosteroids (PDACs) in mothers with antepartum eclampsia <34 weeks gestation benefits the fetus without compromising the mother.

STUDY DESIGN

A case series of 37 maternal-perinatal pairs over a 9-year period with antepartum eclampsia between 24 and 34 weeks gestation from a single tertiary center were reviewed retrospectively. Duration of PDAC, clinical course and maternal-fetal outcomes, including impact of duration of PDAC on neonatal pulmonary function, were recorded for each case. Group assignment was based on length of corticosteroid treatment course before delivery: Group A, 0 to ≤ 24 h, n=28; B, 24 to <48 h, n=5; C, ≥ 48 h, n=4. Data were collected and analyzed by one-way analysis of variance (ANOVA), ANOVA on ranks, χ(2)-test and Fisher's exact tests where appropriate; statistical significance was determined by a P-value <0.05.

RESULT

Overall, 37 of 68 eclampsia patients in 1999 to 2007 met inclusion criteria. No adverse maternal or fetal event occurred while delivery was postponed. Immediate neonatal intubation or continuous positive airway pressure was required for 23/28 in A, 4/5 in B and 2/4 in C; room air was sufficient at birth for 5/28 in A, 1/5 in B and 2/4 in C. No newborn >33 weeks gestation required INI. Prolonged (that is, >1 day) mechanical ventilation was not required for any infant with a gestational age ≥ 32 weeks or PDAC ≥ 48 h. Two of three neonatal deaths in group A were attributed to pulmonary insufficiency.

CONCLUSION

PDAC for antepartum preterm eclampsia, especially ≤ 32 weeks gestation, appears to offer notable fetal pulmonary benefit without significantly increasing maternal or fetal risk.

Blood pressure measurement for hypertension in pregnancy

OBJECTIVE

Ambulatory BP monitoring (ABPM) has been proposed as a logical approach to overcoming many of the problems associated with clinical BP measurement. The extent of its use in diagnosing hypertension in pregnancy is unknown. The objective of this study was to identify the practices surrounding use of ABPM by practitioners to diagnose hypertension (HTN) and white coat hypertension (WCH) in pregnant women.

METHODS

We mailed questionnaires to all obstetricians and family doctors practising obstetrics who were listed in the online medical directory of the College of Physicians and Surgeons of Alberta. Data were analyzed using SPSS.

RESULTS

Completed questionnaires were received from 81 obstetricians and 86 primary care physicians who manage hypertension in pregnancy. The majority of obstetricians (83%) and primary care physicians (79%) indicated that they "almost always" or "often" attempt to differentiate WCH from true HTN in pregnancy. The most popular method identified to differentiate WCH from true HTN in pregnancy was self (intermittent) home BP monitoring (78% of obstetricians and 69% of primary care physicians, P = 0.18). A minority of physicians in each group reported using ABPM to evaluate HTN in pregnancy, with significantly fewer obstetricians using ABPM diagnostically than primary care physicians (12% vs. 26%, P = 0.04).

CONCLUSION

Obstetrical care providers in Alberta are aware that WCH is an issue among pregnant women. While ABPM is chosen in a minority of cases, both obstetricians and primary care physicians appear to have a strong preference to use self BP monitoring for further BP evaluation.

Do Commonly Used Oral Antihypertensives Alter Fetal or Neonatal Heart Rate Characteristics? A Systematic Review

OBJECTIVE

To examine fetal (FHR) and neonatal heart rate patterns following use of common oral antihypertensives in pregnancy.

METHODS

A systematic review of randomized controlled trials (RCTs), observational studies (N >/= 6 women), and animal studies. Data were abstracted (two reviewers) to determine relative risk (RR) (or risk difference (RD) for low event rates) and 95% CI.

RESULTS

Eighteen RCTs (1858 women), one controlled observational study (N = 22), and seven case series (N = 117) were reviewed. Most hypertension was pregnancy-induced (N = 14 studies). The FHR was assessed by cardiotocogram (CTG) (N = 17 studies (visual interpretation); 1 study (computerized CTG), or umbilical artery velocimetry (N = 4). Four studies examined neonatal heart rate. In placebo-controlled RCTs (N = 192 women), adverse FHR effects did not differ between groups [9/101 (drugs) vs. 7/91 (placebo); RD 0.02, 95% CI (- 0.06, 0.11); chi2 = 1.02]. In six drug vs. drug RCTs (295 women), adverse FHR effects did not differ between groups [29/144 (methyldopa) vs. 42/151 (other drugs); RR 0.72, 95% CI (0.49, 1.07); chi2 = 0.69]. In one labetalol vs. placebo trial, neonatal bradycardia did not differ between groups [4/70 (labetalol) vs. 4/74 (placebo); OR 1.06, 95% CI (0.26, 4.39)], while in three drug vs. drug RCTs, neonatal bradycardia was not observed (0/24 vs. 0/26).

CONCLUSIONS

Available data are inadequate to conclude whether oral methyldopa, labetalol, nifedipine, or hydralazine adversely affect fetal or neonatal heart rate and pattern. Until definitive data are available, FHR changes cannot be reliably attributed to drug effect, but may be due to progression of the underlying maternal or placental disease.

Predicting adverse outcomes in women with severe pre-eclampsia

The reason pre-eclampsia matters so much to maternity care providers is that adverse maternal and perinatal events cluster around the diagnosis of proteinuric gestational hypertension. While that is true, most pre-eclampsia is mild and evanescent, resolving rapidly postpartum. Therefore, every effort must be made to identify those women at greatest personal risk, and those bearing fetuses at greatest risk, so that they can be offered closer surveillance and lower thresholds for the use of effective interventions, such as delivery and the use of MgSO(4). Conversely, as delivery remote from term can increase perinatal risks and as liberal MgSO(4) use is associated with maternal morbidity, it may be as important to identify those women who have "mild" disease and bear little personal and/or fetal actuarial risk. For women with "mild" disease at presentation, expectant management remote from term or nonuse of MgSO(4) would be appropriate. Through the PIERS (Pre-eclampsia Integrated Estimate of RiSk) model research program, we have determined that most criteria for "severe" disease perform poorly when operationalized to predict adverse maternal and/or perinatal outcomes. However, with standardized assessment and surveillance of women with suspected and confirmed pre-eclampsia it is possible to lower maternal risks both within individual institutions and across regions. In addition, the PIERS group developed, and is currently validating, 2 outcome prediction models (full-PIERS and mini-PIERS) that we hope will provide an evidence base for the definition of "severe" disease and guide clinical decision-making, especially remote from term when potential perinatal gains are so great.

Hypertensive disorders of pregnancy and long-term risk of hypertension: what do Ontario prenatal care providers know, and what do they communicate?

OBJECTIVES

The objective of this study was to ascertain the knowledge base of Ontario maternity care providers (family physicians, obstetrician-gynaecologists, and midwives) regarding the future health risks of gestational hypertension and preeclampsia and the practices with respect to communication of these risks.

METHODS

In 2004, all obstetricians (639) and midwives (249) in Ontario and a random sample of 600 Ontario family physicians were mailed a survey and a reminder. Non-responders were also sent a second, and in some cases, a third copy of the survey. The survey addressed areas of knowledge, reported practices, and both patient and interprofessional communication. Descriptive analysis was used for the responses.

RESULTS

The overall response rate was 42%. The majority of respondents were familiar with the long-term risks of gestational hypertension and preeclampsia. Although maternity care providers stated that they inform women with these conditions about their subsequent risks and recommend follow-up, only 36% usually inform the women's primary care providers about that subsequent risk. Only 58% of family physicians reported that they are usually informed by the maternity care providers about their patients who developed hypertension in pregnancy, compared with the 83% of maternity care providers who reported that they usually communicate this information to family physicians.

CONCLUSION

We have identified weaknesses in knowledge base and communication amongst Ontario maternity care providers that suggest that the identification and follow-up of women with hypertensive disorders of pregnancy is not occurring. These deficiencies would be amenable to directed educational activities, including reviews, presentations, and the development and implementation of guidelines.

Instituting Surveillance Guidelines and Adverse Outcomes in Preeclampsia

OBJECTIVE

To assess the incidence of combined adverse maternal and perinatal outcomes in women with preeclampsia before and after introducing standardized assessment and surveillance.

METHODS

This study was a preintervention (retrospective) compared with a postintervention (prospective) cohort comparison in a single-tertiary, perinatal unit that included women admitted to hospital with preeclampsia. We interrogated an existing retrospective 24-month database and then introduced the guidelines, assessing the incidence of the combined adverse maternal and perinatal outcomes for 41 months (September 2003 through February 2007). Tests of organ (dys)function were performed at least as often as on the day of admission, admission day +1, every Monday and Thursday, day of delivery, and delivery day +1. All data were checked for errors. The combined maternal outcome was maternal death or one or more of hepatic failure, hematoma, or rupture, Glasgow coma score of less than 13, stroke, at least two seizures, cortical blindness, need for positive inotrope support, myocardial infarction, infusion of any third antihypertensive, renal dialysis, renal transplantation, at least 50% FIO(2) for greater than 1 hour, intubation, or transfusion of at least 10 units of blood products. The combined perinatal outcome was perinatal or infant mortality, bronchopulmonary dysplasia, necrotizing enterocolitis, grade III/IV intraventricular hemorrhage, cystic periventricular leukomalacia, or stage 3-5 retinopathy of prematurity.

RESULTS

Two hundred ninety-five and 405 women were in the preintervention and postintervention cohorts, respectively. The incidence of adverse maternal outcome fell (5.1% to 0.7%; Fisher P<.001; odds ratio 0.14, 95% confidence interval 0.04-0.49). Perinatal outcomes did not change.

CONCLUSION

Standardized surveillance of women with preeclampsia was associated with reduced maternal risk.

Variations in Early and Intermediate Neonatal Outcomes for Inborn Infants Admitted to a Canadian NICU and Born of Hypertensive Pregnancies

OBJECTIVE

To determine whether neonatal intensive care unit (NICU) outcomes vary by centre for inborn neonates of hypertensive pregnancies and, if so, whether that variation might be related to between-centre variations in obstetric practice.

METHODS

The study comprised a prospective cohort of 13 505 singleton neonates admitted to 17 Canadian NICUs. Adjusting for potential confounders, we used multivariate regression to analyze the relation between centre of delivery and 6 dependent variables: (1) Apgar score < 7 at 5 minutes; (2) Score of Neonatal Acute Physiology-II (SNAP-II) score > or = 10; (3) neonatal death; (4) neonatal death or morbidity (owing to bronchopulmonary dysplasia [BPD], intraventricular hemorrhage [IVH], necrotizing enterocolitis [NEC], persistent ductus arteriosus [PDA], or periventricular leukomalacia [PVL]); (5) BPD alone; and (6) major neonatal morbidity (that is, at least one of IVH, PVL, NEC, or PDA). NICU practices known to influence these outcomes were included in the modelling for neonatal death and neonatal morbidity. In a sensitivity analysis for practice variation, antenatal steroid exposure was both included and excluded in each regression.

RESULTS

For 5 of the 6 dependent variables, we identified between-centre variation that was not explained solely by variation in antenatal corticosteroid use. Adjusted odds ratios varied from 0.11 to 5.6 (the reference centre was the median rate of the adverse outcome).

CONCLUSIONS

In the pregnancy hypertension setting, between-centre variations in practice are associated with variations in neonatal physiology and survival. For infants admitted to NICU, the obstetric management of hypertensive pregnancies appears to have an effect on both short- and medium-term neonatal outcomes, even after correction for NICU management.