Catherine Chmiel

The design of a community lifestyle programme to improve the physical and psychological well-being of pregnant women with a BMI of 30 kg/m2 or more.

BackgroundObesity is a global public health issue. Having a BMI of 30 kg/m2 or more (classifying a person as obese) at the start of pregnancy is a significant risk factor for maternal and fetal morbidity. There is a dearth of evidence to inform suitable inteventions to support pregnant women with a BMI of 30 kg/m2 or more. Here we describe a study protocol to test the feasibility of a variety of potential healthy lifestyle interventions for pregnant women with a BMI of 30 kg/m2 or more in a community based programme.Methods/DesignFour hundred women will be approached to attend a 10-week community lifestyle programme. The programme will be provided as a supplement to standard antenatal care. The programme is multi-faceted, aimed at equipping participants with the skills and knowledge needed to adopt healthy behaviours. The social (cognitive) learning theory will be used as a tool to encourage behaviour change, the behaviour change techniques are underpinned by five theoretical components; self-efficacy, outcome expectancies, goal setting, feedback and positive reinforcement.The main outcomes are pregnancy weight gain and caesarean section rate. Other important outcomes include clinical outcomes (e.g., birth weight) and psychological outcomes (e.g., well-being). Secondary outcomes include womens experience of pregnancy and health care services, amount of physical activity, food intake and the suitability of the intervention components.A prospective study using quantitative and qualitative methods will inform the feasibility of implementing the community lifestyle programme with pregnant women with a BMI of 30 kg/m2 or more. Mixed methods of data collection will be used, including diaries, focus groups/interviews, pedometers, validated and specifically designed questionnaires, a programme register, weight gain during pregnancy and perinatal outcome data.DiscussionFindings from this current feasibility study will inform future interventions and NHS services and add to the evidence-base by providing information about the experiences of pregnant women with a BMI of 30 kg/m2 or more undertaking a community lifestyle programme. The study will lead on to a randomised control trial of a suitable intervention to improve the pregnancy outcomes of this target group.Trail RegistrationISRCTN29860479.

The Effect Of Labetalol And Nifedipine MR On Blood Pressure In Women With Chronic Hypertension In Pregnancy

AIM To compare the blood pressure (BP) lowering effects of labetalol and nifedipine modified release (MR) in hypertensive pregnant women. We also investigated the effect on the heart rate (HR) and determined the proportion of time spent in target. METHODS This was an exploratory study. Women with chronic hypertension taking either labetalol or nifedipine were offered 24-h ambulatory blood pressure monitoring (ABPM). Sleep, wake and drug ingestion times were self-reported. An indirect response model was used to analyse the systolic BP (SBP), diastolic BP (DBP) and HR time-series; the effect of gestation and type of drug was evaluated. RESULTS Forty-eight women were recruited: 24 in each group. There was no difference in clinical characteristics. In women taking nifedipine there was a positive association between the dose of nifedipine and pre-dose BP p = .002, this was not present in the labetalol group. There was a difference between the drug effects on both the SBP and DBP time-series (p = .014). In comparison to labetalol, there was less variation in day time BP in those women prescribed nifedipine. Women on labetalol spent a larger proportion of time with their DBP below target (<80 mmHg). The HR dynamics were qualitatively different, a stimulatory effect was found with nifedipine compared to an inhibitory effect with labetalol. CONCLUSION There are significant and important differences between the BP lowering effects of nifedipine and labetalol. A large randomised control trial is required to investigate the relationship between BP variability and time in target on pregnancy outcomes.

Effects of dietary nitrate supplementation, from beetroot juice, on blood pressure in hypertensive pregnant women: A randomised, double-blind, placebo-controlled feasibility trial

Chronic hypertension in pregnancy is associated with significant adverse pregnancy outcomes, increasing the risk of pre-eclampsia, fetal growth restriction and preterm birth. Dietary nitrate, abundant in green leafy vegetables and beetroot, is reduced in vivo to nitrite and subsequently nitric oxide, and has been demonstrated to lower blood pressure, improve vascular compliance and enhance blood flow in non-pregnant humans and animals. The primary aims of this study were to determine the acceptability and efficacy of dietary nitrate supplementation, in the form of beetroot juice, to lower blood pressure in hypertensive pregnant women. In this double-blind, placebo-controlled feasibility trial, 40 pregnant women received either daily nitrate supplementation (70 mL beetroot juice, n = 20) or placebo (70 mL nitrate-depleted beetroot juice, n = 20) for 8 days. Blood pressure, cardiovascular function and uteroplacental blood flow was assessed at baseline and following acute (3 h) and prolonged (8 days) supplementation. Plasma and salivary samples were collected for analysis of nitrate and nitrite concentrations and acceptability of this dietary intervention was assessed based on questionnaire feedback. Dietary nitrate significantly increased plasma and salivary nitrate/nitrite concentrations compared with placebo juice (p < 0.001), with marked variation between women. Compared with placebo, there was no overall reduction in blood pressure in the nitrate-treated group; however there was a highly significant correlation between changes in plasma nitrite concentrations and changes in diastolic blood pressure in the nitrate-treated arm only (r = -0.6481; p = 0.0042). Beetroot juice supplementation was an acceptable dietary intervention to 97% of women. This trial confirms acceptability and potential efficacy of dietary nitrate supplementation in pregnant women. Conversion of nitrate to nitrite critically involves oral bacterial nitrate reductase activities. We speculate that differences in efficacy of nitrate supplementation relate to differences in the oral microbiome, which will be investigated in future studies.

B3. Reproducibility and assessment of longitudinal confounders in the measurement of maternal haemodynamics in women with chronic hypertension in pregnancy

Abstract Introduction: To assess the reproducibility of Tensiomed Arteriograph measurements taken as part of a longitudinal cohort study of women with chronic hypertension (CHT). Methods/Results: chartPulse wave velocity (PWV) and augmentation index (AIX) were measured three times (lying and sitting) per visit at 4–8 weekly intervals from 10 to 34 weeks gestation. Three hundred and ninety-one observations were available from 40 women. PWV and AIX were obtained in 95.4% and 94.6% of attempts. Intraclass coefficients (ICC) were calculated across six gestation windows. The median PWV ICC was 0.71 (range 0.22–0.92), improving to 0.84 (0.78–0.88) for readings with standard deviation <1.5m/s (79.6% of readings). Corresponding AIX ICCs were 0.88 (0.54–0.93) and 0.94 (0.92–0.97). For lying and sitting position measurements, PWV ICC was 0.82 (0.71–0.89) and AIX 0.81 (0.57–0.87). A 10 beat increase in HR was associated with 4.1–5.2% decrease in AIX, adjustment for HR reduced the gestational effect (Figure 1). The effects of HR and gestation on PWV were smaller, but statistically significant.Figure 1. Mixed level regression models (with 95% CI) assessing the interaction between HR, gestation and haemodynamic measurements (fixed effects), adjusted for individual and visit number (random effects). Discussion: PWV and AIX have acceptable reproducibility for use in clinical practice. Changes AIX attributable to HR are consistent with non-pregnant studies and interact with the gestational effect. Reproducibility was unaffected by maternal position, but unacceptable in 20% of readings and additional measures of haemodynamic status may therefore be required.