Monitoring and evaluation of out-of-office blood pressure during pregnancy

Prediction and prevention of preeclampsia in women with preexisting diabetes: the role of home blood pressure, physical activity, and aspirin

Women with type 1 or type 2 (preexisting) diabetes are four times more likely to develop preeclampsia compared with women without diabetes. Preeclampsia affects 9%-20% of pregnant women with type 1 diabetes and 7%-14% of pregnant women with type 2 diabetes. The aim of this narrative review is to investigate the role of blood pressure (BP) monitoring, physical activity, and prophylactic aspirin to reduce the prevalence of preeclampsia and to improve pregnancy outcome in women with preexisting diabetes. Home BP and office BP in early pregnancy are positively associated with development of preeclampsia, and home BP and office BP are comparable for the prediction of preeclampsia in women with preexisting diabetes. However, home BP is lower than office BP, and the difference is greater with increasing office BP. Daily physical activity is recommended during pregnancy, and limiting sedentary behavior may be beneficial to prevent preeclampsia. White coat hypertension in early pregnancy is not a clinically benign condition but is associated with an elevated risk of developing preeclampsia. This renders the current strategy of leaving white coat hypertension untreated debatable. A beneficial preventive effect of initiating low-dose aspirin (150 mg/day) for all in early pregnancy has not been demonstrated in women with preexisting diabetes.

Self-monitoring of blood pressure for preeclampsia patients: Knowledge and attitudes

Background

Preeclampsia is one of the causes of maternal deaths and is also responsible for complications such as premature births worldwide. In South Africa, hypertensive disorders cause 14% of all maternal deaths. Evidence indicates that it may be beneficial to empower women to monitor their blood pressure (BP) in the comfort of their homes.

Objectives

The purpose of this study was to explore and describe preeclampsia patients’ knowledge and attitudes towards the self-monitoring of their BP.

Method

An exploratory, descriptive and contextual qualitative research study was conducted. Fourteen preeclampsia patients were purposively sampled and participated in the study. In-depth semi-structured interviews were used to collect data. Data were analysed using the thematic analytic approach.

Results

The knowledge and attitudes towards the self-monitoring of blood pressure (SMBP) were explored. Four themes emerged, namely understanding of hypertension disorders during pregnancy, openness on self-monitoring at home, its hindrances and benefits. The participants portrayed limited understanding and knowledge of preeclampsia, yet they had positive attitudes towards monitoring BP themselves and were open and willing to do self-monitoring at home.

Conclusion

The use of SMBP may relieve overcrowding in public healthcare institutions. Encouraging patients to participate in self-monitoring could promote active participation and a positive outlook on their pregnancies. The unavailability and unaffordability of the equipment may pose a challenge to women with a low socioeconomic status.

Current prevalence of self-monitoring of blood pressure during pregnancy: the BUMP Survey

OBJECTIVE

To understand the current prevalence of, and attitudes to, self-monitoring of blood pressure (BP) during pregnancy.

METHODS

Five thousand, five hundred and fifty-five pregnant women from antenatal clinics in 16 hospitals in England were invited to complete a survey.

MAIN OUTCOME MEASURES

The primary outcome was the proportion of women currently BP self-monitoring. Secondary outcomes included self-monitoring schedules and women's interactions with clinicians regarding self-monitoring. Population characteristics including risk factors for preeclampsia, ethnicity and deprivation level were considered.

RESULTS

Completed surveys were received and analysed from 5181 pregnant women (93% response rate). Comparison to hospital demographic data suggests that respondents were representative of the UK population. Nine hundred and eighty-three of 5181 (19%) women were currently self-monitoring their BP, constituting 189 of 389 (49%) hypertensive women and 794 of 4792 (17%) normotensive women. However, only 482 of 983 (49%) reported ever sharing this information with antenatal care teams. Of those who self-monitored, 68% (668/983) were able to provide a previous BP reading, compared with 1% (67/5181) of those who did not self-monitor.

CONCLUSION

Many women are now choosing to self-monitor their BP during pregnancy and clinicians should enquire about this proactively and consider providing better information on BP monitoring. Those who self-monitor appear to have better knowledge about their blood pressure. If these findings were replicated nationwide, around 125 000 pregnant women would be currently self-monitoring BP in the UK, yet only half of these women may communicate their readings to their antenatal care teams, suggesting a missed opportunity for enhanced care. Current trials will make the place of self-monitoring in pregnancy clearer.

Differences in visit-to-visit blood pressure variability between normotensive and hypertensive pregnant women

We evaluated the relationship between blood pressure variability (BPV) and the development of hypertension during pregnancy. A total of 4163 pregnant women with normal blood pressure (BP) before 20 weeks of gestation were included in this study. The visit-to-visit blood pressure variability (VVV) was evaluated using the standard deviation (SD) of the systolic BP taken three times during pregnancy at approximately 10, 20, and 30 weeks of gestation. The VVV gradually decreased during pregnancy in normotensive subjects (SD: 7.2 ± 4.2 mmHg, 6.8 ± 3.9 mmHg, and 6.3 ± 3.6 mmHg at 10, 20, and 30 weeks, respectively). However, the VVV of hypertensive subjects did not decrease (SD: 8.2 ± 5.7 mmHg, 7.6 ± 5.0 mmHg, and 8.3 ± 5.3 mmHg at 10, 20, and 30 weeks, respectively) and was significantly greater than the VVV of normotensive subjects (p < 0.001). The VVV was significantly higher in patients who developed hypertension, and there was no decrease in VVV during pregnancy. Pregnancy complications were significantly increased in women with higher VVV at 10 and 30 weeks. Therefore, increased VVV during pregnancy may be a predictor of poor pregnancy outcomes.

The impact of salt intake during and after pregnancy

Although high blood pressure before pregnancy is associated with a risk of gestational hypertension and preeclampsia, no convincing evidence has been produced to show that dietary salt reduction helps in the prevention and treatment of hypertension during pregnancy. Thus the current guidelines do not recommend a sodium restriction during pregnancy to prevent gestational hypertension and the development of preeclampsia. However, the long-term impact of hypertensive disorders of pregnancy for life-threatening diseases later in life is a critical issue. Gestational hypertension could contribute to the risk of developing hypertension later in life, and recent studies have suggested that gestational hypertension and preeclampsia are linked to cardiovascular complications. In this article, we provide an overview of the current perspectives on the salt intake of pregnant women and consider both the short-term influence and the impact beyond the perinatal period.