Obesity in pregnancy: Epidemiology and development of a lifestyle intervention

Obesity, defined as a body mass index of 30 kg/m2 or more, has reached epidemic proportions globally, with more than one-and-a-half billion adults overweight and at least 500 million clinically obese. The prevalence of obesity in the UK has increased by over 300% since 1980. In the UK 24% of adult women are obese and one in six women at an antenatal booking clinic is obese. Obesity has the potential for several detrimental effects on both the mother and the baby. Obese mothers are more likely to develop pre-eclampsia and eclampsia, gestational diabetes and venous thromboembolism. In addition, obese pregnant women are more likely to be induced, often resulting in complicated deliveries such as emergency Caesarean section and shoulder dystocia. Obesity significantly increases the risk of maternal mortality during or after pregnancy. Babies born to obese mothers are at an increased risk of congenital abnormalities, preterm deliveries and stillbirth, and children exposed to maternal obesity are at an increased risk of developing metabolic syndrome in later life. The aim of this work was to assess the extent and potential for the prevention of adverse impacts of obesity in pregnancy. The specific objectives were to: summarise the literature on maternal obesity and adverse pregnancy outcome; perform an epidemiological analysis using local data of obesity in pregnancy; conduct a systematic review of existing evidence on lifestyle interventions for obesity in pregnancy; and to develop and evaluate a multi-component pilot study for a community-based intervention for maternal obesity in South London. Analysis of delivery data from South London between January 2004 and May 2012 showed the overall prevalence of maternal obesity to be 15%, with considerable variation by ethnic group. There was a strong association between rising body mass index and risk of adverse pregnancy outcome, especially diabetes. The effect of obesity on diabetes in pregnancy was more pronounced in Asians and Orientals compared to other ethnic groups. Calculations of population attributable risk fractions showed that, if we were able to prevent obesity before pregnancy in this population, around one-third of diabetes in pregnancy could be prevented. The data alluded to the fact that the benefit of obesity reduction would be greater in Blacks than in other ethnic groups because of the higher prevalence of obesity in this group. A complex community-based lifestyle intervention called the Community Activity and Nutrition (CAN) programme was developed for delivery by health trainers in children’s/Sure Start centres. The research showed that it is feasible to deliver the CAN intervention in children’s/Sure Start centres (Effra in Brixton, Jessop in Herne Hill and Jubilee in Tulse Hill) in an Inner London socially deprived community. The pilot study encountered problems with recruitment resulting from understaffing and lack of participant time. However, once recruited, retention on the programme was good. There was some evidence that the intervention improved selected clinical outcomes. Further work is ongoing to establish the clinical and cost effectiveness of the intervention. If CAN is shown to be clinically effective and cost-effective, the translation of this research and adoption by policy makers into the wider community may help to ameliorate the adverse outcomes associated with obesity in pregnancy

Birth Weights in Sickle Cell Disease Pregnancies: A Cohort Study.

Pregnancy in women with Sickle Cell Disease (SCD) has been linked with an increased incidence of adverse foetal outcomes when compared to women without haemoglobinopathies (HbAA). There's a paucity of data into foetal outcomes for infants born to women with SCD. Customised growth charts have been demonstrated to be better than population-based growth charts at identifying unhealthy small babies. We analysed the mean birth weight and customised birth weight centiles of infants born to mothers with SCD versus mothers with HbAA genotype, to quantify the risk of having a smaller baby. Birth weight and birth weight centiles were analysed for 88 women with SCD (50 HbSS; 38 HbSC) and 176 controls (HbAA). Statistically significant differences were seen in the mean birth weight (P value = 0.004) and the mean birth weight centiles (P value = 0.016). We conclude that SCD is a risk factor for having a smaller baby

Preferences for prenatal diagnosis of sickle-cell disorder: A discrete choice experiment comparing potential service users and health-care providers

BACKGROUND: Non-invasive prenatal diagnosis (NIPD) for sickle-cell disorder (SCD) is moving closer to implementation and studies considering stakeholder preferences are required to underpin strategies for offering NIPD in clinical practice. OBJECTIVE: Determine service user and provider preferences for key attributes of prenatal diagnostic tests for SCD and examine views on NIPD. METHOD: A questionnaire that includes a discrete choice experiment was used to determine the preferences of service users and providers for prenatal tests that varied across three attributes: accuracy, time of test and risk of miscarriage. RESULTS: Adults who were carriers of SCD or affected with the condition (N=67) were recruited from haemoglobinopathy clinics at two maternity units. Health professionals, predominately midwives, who offer antenatal care (N=62) were recruited from one maternity unit. No miscarriage risk was a key driver of decision making for both service users and providers. Service providers placed greater emphasis on accuracy than service users. Current uptake of invasive tests was 63%, whilst predicted uptake of NIPD was 93.8%. Many service users (55.4%) and providers (52.5%) think pressure to have prenatal testing will increase when NIPD for SCD becomes available. CONCLUSIONS: There are clear differences between service users and health professionals' preferences for prenatal tests for sickle-cell disorder. The safety of NIPD is welcomed by parents and uptake is likely to be high. To promote informed choice, pretest counselling should be balanced and not exclusively focused on test safety. Counselling strategies that are sensitive to feelings of pressure to test will be essential

Can birth outcome inequality be reduced using targeted caseload midwifery in a deprived diverse inner city population? A retrospective cohort study, London, UK.

Objectives(1) To report maternal and newborn outcomes of pregnant women in areas of social deprivation in inner city London. (2) To compare the effect of caseload midwifery with standard care on maternal and newborn outcomes in this cohort of women.DesignRetrospective observational cohort study.SettingFour council wards (electoral districts) in inner city London, where over 90% of residents are in the two most deprived quintiles of the English Index of Multiple Deprivation (IMD) (2019) and the population is ethnically diverse.ParticipantsAll women booked for antenatal care under Guys and St Thomas' National Health Service Foundation Trust after 11 July 2018 (when the Lambeth Early Action Partnership (LEAP*) caseload midwifery team was implemented) until data collection 18 June 2020. This included 523 pregnancies in the LEAP area, of which 230 were allocated to caseload midwifery, and 8430 pregnancies from other areas.Main outcome measuresTo explore if targeted caseload midwifery (known to reduce preterm birth) will improve important measurable outcomes (preterm birth, mode of birth and newborn outcomes).ResultsThere was a significant reduction in preterm birth rate in women allocated to caseload midwifery, when compared with those who received traditional midwifery care (5.1% vs 11.2%; risk ratio: 0.41; p=0.02; 95% CI 0.18 to 0.86; number needed to treat: 11.9). Caesarean section births were significantly reduced in women allocated to caseload midwifery care, when compared with traditional midwifery care (24.3% vs 38.0%; risk ratio: 0.64: p=0.01; 95% CI 0.47 to 0.90; number needed to treat: 7.4) including emergency caesarean deliveries (15.2% vs 22.5%; risk ratio: 0.59; p=0.03; 95% CI 0.38 to 0.94; number needed to treat: 10) without increase in neonatal unit admission or stillbirth.ConclusionThis study shows that a model of caseload midwifery care implemented in an inner city deprived community improves outcome by significantly reducing preterm birth and birth by caesarean section when compared with traditional care. This data trend suggests that when applied to targeted groups (women in higher IMD quintile and women of diverse ethnicity) that the impact of intervention is greater

Perinatal outcomes in women with sickle cell disease: a matched cohort study from London, UK.

There are limited data on contemporary outcomes for women with sickle cell disease (SCD) in pregnancy. We conducted a single-site matched cohort study, comparing 131 pregnancies to women with SCD between 2007 and 2017 to a comparison group of 1310 pregnancies unaffected by SCD. Restricting our analysis to singleton pregnancies that reached 24 weeks of gestation, we used conditional Poisson regression to estimate adjusted risk ratios (aRRs) for perinatal outcomes. Infants born to mothers with SCD were more likely to be small for gestational age [aRR 1·69, 95% confidence interval (CI) 1·13-2·48], preterm (aRR 2·62, 95% CI 1·82-3·78) and require Neonatal Unit (NNU) admission (aRR 3·59, 95% CI 2·18-5·90). Pregnant women with SCD were at higher risk of pre-eclampsia/eclampsia (aRR 3·53, 95% CI 2·00-6·24), more likely to receive induction of labour (aRR 2·50, 95% CI 1·82-1·76) and caesarean birth (aRR 1·44, 95% CI 1·18-1·76). In analysis stratified by genotype, the risk of adverse outcomes was highest in haemoglobin SS (HbSS) pregnancies (n = 80). There was no strong evidence that haemoglobin SC (HbSC) pregnancies (n = 46) were at higher risk of preterm birth, caesarean delivery, or NNU admission. Pre-eclampsia/eclampsia was more frequently observed in HbSC pregnancies. Despite improvements in the care of pregnant women with SCD, the increased risk of adverse perinatal outcomes remains

Early Antenatal Prediction of Gestational Diabetes in Obese Women: Development of Prediction Tools for Targeted Intervention.

All obese women are categorised as being of equally high risk of gestational diabetes (GDM) whereas the majority do not develop the disorder. Lifestyle and pharmacological interventions in unselected obese pregnant women have been unsuccessful in preventing GDM. Our aim was to develop a prediction tool for early identification of obese women at high risk of GDM to facilitate targeted interventions in those most likely to benefit. Clinical and anthropometric data and non-fasting blood samples were obtained at 15+0-18+6 weeks' gestation in 1303 obese pregnant women from UPBEAT, a randomised controlled trial of a behavioural intervention. Twenty one candidate biomarkers associated with insulin resistance, and a targeted nuclear magnetic resonance (NMR) metabolome were measured. Prediction models were constructed using stepwise logistic regression. Twenty six percent of women (n = 337) developed GDM (International Association of Diabetes and Pregnancy Study Groups criteria). A model based on clinical and anthropometric variables (age, previous GDM, family history of type 2 diabetes, systolic blood pressure, sum of skinfold thicknesses, waist:height and neck:thigh ratios) provided an area under the curve of 0.71 (95%CI 0.68-0.74). This increased to 0.77 (95%CI 0.73-0.80) with addition of candidate biomarkers (random glucose, haemoglobin A1c (HbA1c), fructosamine, adiponectin, sex hormone binding globulin, triglycerides), but was not improved by addition of NMR metabolites (0.77; 95%CI 0.74-0.81). Clinically translatable models for GDM prediction including readily measurable variables e.g. mid-arm circumference, age, systolic blood pressure, HbA1c and adiponectin are described. Using a ≥35% risk threshold, all models identified a group of high risk obese women of whom approximately 50% (positive predictive value) later developed GDM, with a negative predictive value of 80%. Tools for early pregnancy identification of obese women at risk of GDM are described which could enable targeted interventions for GDM prevention in women who will benefit the most

Dietary patterns in obese pregnant women; influence of a behavioral intervention of diet and physical activity in the UPBEAT randomized controlled trial.

BACKGROUND: Understanding dietary patterns in obese pregnant women will inform future intervention strategies to improve pregnancy outcomes and the health of the child. The aim of this study was to investigate the effect of a behavioral intervention of diet and physical activity advice on dietary patterns in obese pregnant woman participating in the UPBEAT study, and to explore associations of dietary patterns with pregnancy outcomes. METHODS: In the UPBEAT randomized controlled trial, pregnant obese women from eight UK multi-ethnic, inner-city populations were randomly assigned to receive a diet/physical activity intervention or standard antenatal care. The dietary intervention aimed to reduce glycemic load and saturated fat intake. Diet was assessed using a food frequency questionnaire (FFQ) at baseline (15(+0)-18(+6) weeks' gestation), post intervention (27(+0)-28(+6) weeks) and in late pregnancy (34(+0)-36(+0) weeks). Dietary patterns were characterized using factor analysis of the baseline FFQ data, and changes compared in the control and intervention arms. Patterns were related to pregnancy outcomes in the combined control/intervention cohort (n = 1023). RESULTS: Four distinct baseline dietary patterns were defined; Fruit and vegetables, African/Caribbean, Processed, and Snacks, which were differently associated with social and demographic factors. The UPBEAT intervention significantly reduced the Processed (-0.14; 95% CI -0.19, -0.08, P <0.0001) and Snacks (-0.24; 95% CI -0.31, -0.17, P <0.0001) pattern scores. In the adjusted model, baseline scores for the African/Caribbean (quartile 4 compared with quartile 1: OR = 2.46; 95% CI 1.41, 4.30) and Processed (quartile 4 compared with quartile 1: OR = 2.05; 95% CI 1.23, 3.41) patterns in the entire cohort were associated with increased risk of gestational diabetes. CONCLUSIONS: In a diverse cohort of obese pregnant women an intensive dietary intervention improved Processed and Snack dietary pattern scores. African/Caribbean and Processed patterns were associated with an increased risk of gestational diabetes, and provide potential targets for future interventions. TRIAL REGISTRATION: Current controlled trials; ISRCTN89971375

Maternal obesity support services: a qualitative study of the perspectives of women and midwives

Background - Twenty percent of pregnant women in the UK are obese (BMI ≥ 30 kg/m2), reflecting the growing public health challenge of obesity in the 21st century. Obesity increases the risk of adverse outcomes during pregnancy and birth and has significant cost implications for maternity services. Gestational weight management strategies are a high priority; however the evidence for effective, feasible and acceptable weight control interventions is limited and inconclusive. This qualitative study explored the experiences and perceptions of pregnant women and midwives regarding existing support for weight management in pregnancy and their ideas for service development. Methods - A purposive sample of 6 women and 7 midwives from Doncaster, UK, participated in two separate focus groups. Transcripts were analysed thematically. Results - Two overarching themes were identified, 'Explanations for obesity and weight management' and 'Best care for pregnant women'. 'Explanations' included a lack of knowledge about weight, diet and exercise during pregnancy; self-talk messages which excused overeating; difficulties maintaining motivation for a healthy lifestyle; the importance of social support; stigmatisation; and sensitivity surrounding communication about obesity between midwives and their clients. 'Best care' suggested that weight management required care which was consistent and continuous, supportive and non-judgemental, and which created opportunities for interaction and mutual support between obese pregnant women. Conclusions - Women need unambiguous advice regarding healthy lifestyles, diet and exercise in pregnancy to address a lack of knowledge and a tendency towards unhelpful self-talk messages. Midwives expressed difficulties in communicating with their clients about their weight, given awareness that obesity is a sensitive and potentially stigmatising issue. This indicates more could be done to educate and support them in their work with obese pregnant women. Motivation and social support were strong explanatory themes for obesity and weight management, suggesting that interventions should focus on motivational strategies and social support facilitation