Effects of maternal anthropometrics on pregnancy outcomes in South Asian women: a systematic review

AIM

This systematic review investigates associations between maternal pre-pregnancy/early-pregnancy anthropometrics (e.g. weight and body fat), anthropometric change and pregnancy outcomes in South Asian and White women.

METHODS

Twelve electronic literature databases, reference lists and citations of all included studies were searched. Observational studies published in the English language were included. Descriptive synthesis was used to summarize the evidence base.

RESULTS

Twenty-two studies met the inclusion criteria (403,609 births [351,856 White and 51,753 South Asian]). Nine were prospective cohort studies, nine were retrospective cohort studies and two were cross-sectional studies. Results suggested that in South Asian women, maternal pre-pregnancy/early-pregnancy anthropometrics were associated with anthropometric change, birthweight, mode of delivery and gestational diabetes mellitus (GDM). Gestational anthropometric change was found to be associated with GDM. There was limited evidence to suggest that there may be associations between maternal pre-anthropometrics/early anthropometrics and hypertensive disorders, stillbirth, congenital anomalies, post-natal weight retention and post-natal impaired glucose tolerance. The evidence suggested a combined effect of pre-pregnancy/early-pregnancy anthropometrics and gestational anthropometric change on both GDM and post-natal weight retention.

CONCLUSION

The increased risk of adverse pregnancy outcomes in South Asian women should be considered in guidelines for weight management before and during pregnancy.

Maternal body mass index and post-term birth: a systematic review and meta-analysis

Post-term birth is a preventable cause of perinatal mortality and severe morbidity. This review examined the association between maternal body mass index (BMI) and post-term birth at ≥42 and ≥41 weeks' gestation. Five databases, reference lists and citations were searched from May to November 2015. Observational studies published in English since 1990 were included. Linear and nonlinear dose-response meta-analyses were conducted by using random effects models. Sensitivity analyses assessed robustness of the results. Meta-regression and sub-group meta-analyses explored heterogeneity. Obesity classes were defined as I (30.0-34.9 kg m-2 ), II (35.0-39.9 kg m-2 ) and III (≥40 kg m-2 ; IIIa 40.0-44.9 kg m-2 , IIIb ≥ 45.0 kg m-2 ). Searches identified 16,375 results, and 39 studies met the inclusion criteria (n = 4,143,700 births). A nonlinear association between maternal BMI and births ≥42 weeks was identified; odds ratios and 95% confidence intervals for obesity classes I-IIIb were 1.42 (1.27-1.58), 1.55 (1.37-1.75), 1.65 (1.44-1.87) and 1.75 (1.50-2.04) respectively. BMI was linearly associated with births ≥41 weeks: odds ratio is 1.13 (95% confidence interval 1.05-1.21) for each 5-unit increase in BMI. The strength of the association between BMI and post-term birth increases with increasing BMI. Odds are greatest for births ≥42 weeks among class III obesity. Targeted interventions to prevent the adverse outcomes associated with post-term birth should consider the difference in risk between obesity classes.

Implementation of pregnancy weight management and obesity guidelines: a meta-synthesis of healthcare professionals' barriers and facilitators using the Theoretical Domains Framework

Obesity in pregnancy is rising and is associated with severe health consequences for both the mother and the child. There is an increasing international focus on guidelines to manage the clinical risks of maternal obesity, and for pregnancy weight management. However, passive dissemination of guidelines is not effective and more active strategies are required for effective guideline implementation into practice. Implementation of guidelines is a form of healthcare professional behaviour change, and therefore implementation strategies should be based on appropriate behaviour change theory. This systematic review aimed to identify the determinants of healthcare professionals' behaviours in relation to maternal obesity and weight management. Twenty-five studies were included. Data synthesis of the existing international qualitative and quantitative evidence base used the Theoretical Domains Framework to identify the barriers and facilitators to healthcare professionals' maternal obesity and weight management practice. The domains most frequently identified included 'knowledge', 'beliefs about consequences' and 'environmental context and resources'. Healthcare professionals' weight management practice had the most barriers compared with any other area of maternal obesity practice. The results of this review will be used to inform the development of an intervention to support healthcare professional behaviour change.

The impact of maternal BMI status on pregnancy outcomes with immediate short-term obstetric resource implications: a meta-analysis

Obesity is rising in the obstetric population, yet there is an absence of services and guidance for the management of maternal obesity. This systematic review aimed to investigate relationships between obesity and impact on obstetric care. Literature was systematically searched for cohort studies of pregnant women with anthropometric measurements recorded within 16-weeks gestation, followed up for the term of the pregnancy, with at least one obese and one comparison group. Two researchers independently data-extracted and quality-assessed each included study. Outcome measures were those that directly or indirectly impacted on maternity resources. Primary outcomes included instrumental delivery, caesarean delivery, duration of hospital stay, neonatal intensive care, neonatal trauma, haemorrhage, infection and 3rd/4th degree tears. Meta-analysis shows a significant relationship between obesity and increased odds of caesarean and instrumental deliveries, haemorrhage, infection, longer duration of hospital stay and increased neonatal intensive care requirement. Maternal obesity significantly contributes to a poorer prognosis for mother and baby during delivery and in the immediate post-partum period. National clinical guidelines for management of obese pregnant women, and public health interventions to help safeguard the health of mothers and their babies are urgently required.

Trends in maternal obesity incidence rates, demographic predictors, and health inequalities in 36,821 women over a 15-year period

OBJECTIVE

The aim of this study was to identify trends in maternal obesity incidence over time and to identify those women most at risk and potential-associated health inequalities.

DESIGN

Longitudinal database study.

SETTING

James Cook University Hospital maternity unit, Middlesbrough, UK.

SAMPLE

A total of 36 821 women from 1 January 1990 to 31 December 2004.

METHODS

Trends in maternal obesity incidence over time were analysed using chi-square test for trend. Demographic predictor variables were analysed using multivariate logistic regression, adjusting for confounding factors after testing for multicollinearity. National census data were used to place the regional data into the context of the general population.

MAIN OUTCOME MEASURE

Trends in maternal obesity incidence. Demographic predictor variables included ethnic group, age, parity, marital status, employment and socio-economic disadvantage.

RESULTS

The proportion of obese women at the start of pregnancy has increased significantly over time from 9.9 to 16.0% (P<0.01). This is best described by a quadratic model (P<0.01) showing that the rate is accelerating; by 2010, the rate will have increased to 22% of this population if the trend continues. There is also a significant relationship with maternal obesity and mothers' residing in areas of most deprivation (odds ratio [OR]=2.44, 95% CI=1.98, 3.02, P<0.01), with increasing age (OR=1.04, 95% CI=1.04, 1.05, P<0.01), and parity (OR=1.17, 95% CI=1.12, 1.21, P<0.01).

CONCLUSIONS

The incidence of maternal obesity at the start of pregnancy is increasing and accelerating. Predictors of maternal obesity are associated with health inequalities, particularly socio-economic disadvantage.

Obesity in pregnancy: a study of the impact of maternal obesity on NHS maternity services

OBJECTIVE

To gain a detailed understanding of healthcare professionals' perceptions of the impact that caring for obese pregnant women has on maternity services.

DESIGN

Qualitative interview study using purposeful sampling and face-to-face interviews.

SETTING

Sixteen maternity units in NHS Trusts in the North East Government Office Region of England, UK.

SAMPLE

Thirty-three maternity and obstetric healthcare professionals with personal experience of managing the care of obese pregnant women.

METHODS

Semi-structured interviews with healthcare professionals representing each maternity unit in the region. Transcripts were analysed using systematic content analysis.

MAIN OUTCOME MEASURES

Views on the impact maternal obesity has on maternity services, the facilities required to care for obese mothers in pregnancy, and existing services directed towards maternal obesity.

RESULTS

Five dominant themes relating to service delivery emerged; booking appointments, equipment, care requirements, complications and restrictions, and current and future management of care. Many of the issues identified were associated with managing the care of obese women in pregnancy safely, resources and cost issues to be able to do this, multidisciplinary care requirements because of coexisting morbidities when the mother is obese, and restricted care options and patient choice.

CONCLUSIONS

Healthcare professionals in the North East of England feel that maternal obesity has a major impact on services and resource, on the health of both the mother and child, and on the psychological wellbeing of the mother.