Characterising and monitoring preconception health in England: a review of national population-level indicators and core data sources

Developing a preconception medical record audit tool for general practice: a multimethod study

Background Preconception health risk factors documented in general practice electronic medical records help general practitioners (GPs) understand the proportion and type of risks among women attending their practice. We aimed to collaborate with GPs to develop an audit tool for collecting preconception health data from structured electronic medical record fields. Methods This was a three-phase multimethod study. In Phase 1, we developed a preliminary audit tool informed by the literature. In Phase 2, we collaborated with GPs for feedback. In Phase 3, we finalised the audit tool. Results The preliminary audit tool comprised 25 preconception health risk factors, of which three were removed following GP feedback (second-hand smoke, social history, history of sexually transmitted infections). The final audit tool comprised 22 preconception health risk factors. Conclusion This audit tool may assist researchers in understanding the proportion of patients visiting general practice with preconception health risk factors, thereby facilitating the future development of a screening process that may be used to identify and provide preconception care to women who may most benefit from it.

Preconception health policy, health promotion, and health services to achieve health in current and future generations: a narrative review

Non-communicable diseases (NCDs) represent the leading cause of death and disability worldwide, and those NCDs contributing most burden - cardiometabolic illness, diabetes, cancer, chronic respiratory disease - can be largely prevented through improvements in health behaviours such as tobacco use, harmful use of alcohol, exposure to environmental hazards, unhealthy dietary habits, and physical inactivity. Despite concerted efforts at all levels of health care provision and policy, population-level health behaviour change still presents an ongoing challenge to primary care clinicians, public health practitioners, health promotion specialists and government agencies around the world. An individual's age can influence their health behaviour decision-making as younger people often perceive the potential implications of their current poor health behaviours as remote in time and possibility, which may significantly limit their motivation to make a positive health behaviour change in the present. Yet public health researchers and practitioners recognise that a lifecourse approach to public health policies and interventions has the potential to reduce the risk of NCDs developing before conception and throughout life, as well as impacting the transmission of the benefits of health improvement from one generation to the next. Given the growing awareness of the benefits of a lifecourse approach to public health, a focus on improving preconception health at a population-level provides a unique opportunity for behaviour change motivation, NCD prevention and reducing inequalities across generations. Through this narrative review, we describe how three main public health strategies - health policy, health promotion and health services - may address the challenge of improving preconception health. We also explore the potential value of leveraging parental motivation in the preconception period to achieve positive health behaviour change and, in doing so, meet broader public health goals. We set out a framework for drawing on established public health methods and priorities to address structural inequalities and harness parental motivation and concern for their offspring to build and enable new and positive health behaviours that benefit current and future generations.

Preconception indicators and associations with health outcomes reported in UK routine primary care data: a systematic review

BACKGROUND

Routine primary care data may be a valuable resource for preconception health research and to inform the provision of preconception care.

AIM

To review how primary care data could provide information on the prevalence of preconception indicators and examine associations with maternal and offspring health outcomes.

DESIGN AND SETTING

Systematic review of observational studies using UK routine primary care data.

METHOD

Literature searches were conducted in March 2023 using five databases to identify observational studies that used national primary care data from individuals aged 15-49 years. Preconception indicators were defined as medical, behavioural, and social factors that may impact future pregnancies; health outcomes included those that may occur during and after pregnancy.

RESULTS

From 5259 screened records, 42 articles were included. The prevalence of 37 preconception indicator measures was described for female patients, ranging from 0.01% for sickle cell disease to >20% for each of advanced maternal age, previous caesarean section (among those with a recorded pregnancy), overweight, obesity, smoking, depression, and anxiety (irrespective of pregnancy). Few studies reported indicators for male patients (n = 3) or associations with outcomes (n = 5). Most studies had a low risk of bias, but missing data may limit generalisability of the findings.

CONCLUSION

The findings demonstrated that routinely collected UK primary care data could be used to identify patients' preconception care needs. Linking primary care data with health outcomes collected in other datasets is underutilised, but could help to quantify how optimising preconception health and care could reduce adverse outcomes for mothers and children.

Preconception health in adolescence and adulthood across generations in the UK: Findings from three British birth cohort studies

Optimising preconception health in women and men holds significant potential for improving pregnancy and offspring health outcomes. To create a picture of the state of preconception health in the UK, this study aimed to describe the prevalence of and changes in preconception health indicators reported in three British birth cohort studies: the 1970 British Birth Cohort Study (BCS70; born in 1970; N = 17,198), Next Steps (1989-1990; N = 15,770), and Millennium Cohort Study (MCS; 2000-2002; N = 19,517). The analysis focused on data obtained during participants' adolescence (16-17 years) and subsequent follow-ups at 25-26 years for BCS70 and Next Steps. Self-reported preconception indicators were defined in line with a previously published review and reported as proportions. Across cohorts, data were available for 14 preconception indicators across four domains: health behaviours and weight, reproductive health and family planning, physical health conditions, and wider determinants of health. However, data for these indicators were not consistently available for all cohort members. Findings suggested persistent suboptimal health behaviours in both genders and across generations, including low intakes of fruit. While alcohol, tobacco, and soft drink intake decreased across generations, obesity prevalence surged. This study underscores the need for public health interventions targeting the root causes of adverse health behaviours towards improvement of fruit consumption, further reduction in alcohol, tobacco, and soft drink consumption, and addressing the escalating obesity rates among individuals of reproductive age. Ongoing monitoring is needed to continue tracking these existing indicators over time, while improved data quality and availability of a wider range of preconception indicators are crucial to comprehensively understanding the complexities of preconception health, enabling the development of more targeted and effective interventions.

Preconception health among migrant women in England: A cross-sectional analysis of maternity services data 2018-2019

Background

Perinatal outcomes are poor among migrant women in vulnerable situations, but little is known about their health preconception. We investigated preconception health inequalities between migrant women in vulnerable situations and non-migrant women.

Methods

This national cross-sectional study used data from the NHS Maternity Services Data Set (MSDS) version 1.5, incorporating NHS maternity services in England. All 652,880 women with an antenatal booking appointment between 1/4/2018 and 31/3/2019 were included. Migration category data were available for 66.2 % (n = 432,022). Odds ratios were calculated comparing preconception indicators among probable migrants in vulnerable situations (English not their first language with complex social factors (CSF)), probable migrants not in vulnerable situations (English not their first language without CSF), probable non-migrants in vulnerable situations (English their first language with CSF) and probable non-migrants not in vulnerable situations (English their first language without CSF). CSF include recent migrants, asylum seekers, refugees, difficulty reading/speaking English; alcohol and/or drugs misuse; aged under 20; and/or experiencing domestic abuse.

Findings

We identified 3.8 % (25,070 women) of the study population as probable migrants in vulnerable situations, 10.2 % (66,783 women) as probable migrants not in vulnerable situations, 5.6 % (36,433 women) as probable non-migrants in vulnerable situations, 46.5 % (303,737 women) as probable non-migrants not in vulnerable situations, and 33.8 % as having missing migration category data. Probable migrants in vulnerable situations (n = 25,070) had over twice the odds of not taking folic acid preconception compared to probable non-migrants not in vulnerable situations (odds ratio 2.15, 95 % confidence interval 2.06-2.25). They had increased odds of previous obstetric complications and being underweight, but lower odds of physical and mental health conditions (apart from diabetes and hepatitis b), smoking and overweight or obesity.

Interpretation

Inequalities exist across many preconception indicators, highlighting opportunities to improve preconception health in this population to reduce health inequalities and improve perinatal and neonatal outcomes.

Funding

Medical Research Council.

Preconception health risk factors documented in general practice electronic medical records

BACKGROUND

Documenting medical and lifestyle preconception health risk factors in electronic medical records (EMRs) could assist general practitioners (GPs) to identify those reproductive-aged women who could most benefit from preconception care (PCC). However, it is unclear to what extent PCC risk factors are identifiable in general practice records. This study aimed to determine the extent to which medical and lifestyle preconception health risk factors are documented in general practice EMRs.

METHODS

We conducted an audit of the documentation of medical and lifestyle preconception risk factors in 10 general practice EMRs in Melbourne, Australia. We retrospectively analysed the EMRs of 100 consecutive women aged 18-44 years who visited each practice between January and September 2022. Using a template informed by PCC guidelines, we extracted data from structured fields in the EMR and conducted a descriptive analysis.

RESULTS

Among the data extracted, the more commonly documented medical and lifestyle preconception health risk factors in the EMRs included smoking (79%), blood pressure (74%), alcohol consumption (63%) and body mass index (57%). Among the women audited, 14% were smokers, 24% were obese, 7% had high blood pressure, 5% had diabetes, 28% had a mental health condition, 13% had asthma, 6% had thyroid disease and 17% had been prescribed and could be using a potentially teratogenic medication.

CONCLUSIONS

Better documentation of medical and lifestyle preconception health risk factors in structured fields in EMRs may potentially assist primary care providers including GPs in identifying and providing PCC to women who could most benefit from it.

Preconception health and care policies, strategies and guidelines in the UK and Ireland: a scoping review

BACKGROUND

Preconception health has the potential to improve parental, pregnancy and infant outcomes. This scoping review aims to (1) provide an overview of the strategies, policies, guidelines, frameworks, and recommendations available in the UK and Ireland that address preconception health and care, identifying common approaches and health-influencing factors that are targeted; and (2) conduct an audit to explore the awareness and use of resources found in the scoping review amongst healthcare professionals, to validate and contextualise findings relevant to Northern Ireland.

METHODS

Grey literature resources were identified through Google Advanced Search, NICE, OpenAire, ProQuest and relevant public health and government websites. Resources were included if published, reviewed, or updated between January 2011 and May 2022. Data were extracted into Excel and coded using NVivo. The review design included the involvement of the "Healthy Reproductive Years" Patient and Public Involvement and Engagement advisory panel.

RESULTS

The searches identified 273 resources, and a subsequent audit with healthcare professionals in Northern Ireland revealed five additional preconception health-related resources. A wide range of resource types were identified, and preconception health was often not the only focus of the resources reviewed. Resources proposed approaches to improve preconception health and care, such as the need for improved awareness and access to care, preconceptual counselling, multidisciplinary collaborations, and the adoption of a life-course approach. Many behavioural (e.g., folic acid intake, smoking), biomedical (e.g., mental and physical health conditions), and environmental and social (e.g., deprivation) factors were identified and addressed in the resources reviewed. In particular, pre-existing physical health conditions were frequently mentioned, with fewer resources addressing psychological factors and mental health. Overall, there was a greater focus on women's, rather than men's, behaviours.

CONCLUSIONS

This scoping review synthesised existing resources available in the UK and Ireland to identify a wide range of common approaches and factors that influence preconception health and care. Efforts are needed to implement the identified resources (e.g., strategies, guidelines) to support people of childbearing age to access preconception care and optimise their preconception health.

What preconception health services would the public find when searching the internet in Australia?: results from a simulated internet-search study

BACKGROUND

Australian preventive health strategy outlines the importance of preconception health in improving health in the community, across multiple generations and places primary and community healthcare services as a central pillar to effective preconception care. However, there is no national implementation plan to see preconception care proactively offered in healthcare settings in Australia. Instead, there is evidence that most women search the internet for information about pregnancy planning and preparation. In response, this study explores the availability and characteristics of health services found by searching for preconception care online in Australia.

METHOD

Simulated Google searches were conducted using search terms 'preconception' and the name of a city/town with a population > 50,000. Related terms, 'fertility' and 'pregnancy' were also searched. Characteristics of the health services and the information available on relevant websites were extracted and reported descriptively.

RESULTS

The searches identified 831 website links, including 430 websites for health services. The health services were most often located in cities/towns with populations equal to or less than 200 000 (54.2%), and housing multiple health professionals (69.8%) including a specialist doctor (66.5%), nurse (20.9%), psychologist/counsellor (2.0%) and/or naturopath (13.0%). All the health services identified online explicitly mentioned women among their target populations, while 69.1% (n = 297) also referred to providing services for men or partners. More than one third of websites included blogs (36.9%) while external links were included in 10.8% of the online sites.

CONCLUSIONS

This study provides a preliminary examination of health services that may be found through internet-based searching by Australian consumers seeking health advice or support prior to becoming pregnant. Our descriptive results suggest couples may find a variety of health professionals when seeking health services for preconception care. Future research involving co-design of search terms with consumers, ongoing monitoring of health services and ensuring access to meaningful, and accurate information found through internet-searching are all necessary to ensure people of reproductive age are able to access the preconception health information and care they need.

Prevalence of preconception health indicators among Brazilian women of reproductive age

This article aims to evaluate the performance of preconception health indicators according to sociodemographic characteristics among Brazilian women of reproductive age. We conducted a descriptive epidemiological study using data from 21,645 and 25,228 women, respectively, who responded the 2013 and 2019 national health surveys, and data for the period 2010 to 2020 derived from the national health system's Department of Informatics (DATASUS). We calculated the prevalence of indicators according to sociodemographic characteristics and statistical significance of differences was measured using Pearson's chi-squared test. Syphilis and HIV incidence rates were also calculated. There was an increase in the prevalence of access to health service indicators (medical and dental consultations and recent Pap smear). However, there was an increase in the prevalence of hypertension, alcohol use, and obesity. The prevalence of use of contraceptive methods and fertility treatment remained stable. Syphilis incidence increased sevenfold between 2010 and 2020. Black/brown women with a low level of education, higher parity, and living in the North or Northeast performed worse for preconception health indicators. Despite the increase in access to health services, performance on preconception health indicators declined and health inequities continued.

Using a validated instrument to assess pregnancy planning and preconception care at antenatal booking visits: a retrospective cohort study

OBJECTIVE

To determine the completion rate for the London Measure of Unplanned Pregnancy (LMUP), a psychometrically validated measure of a woman's intention with regard to a current or recent pregnancy, during booking visits at two metropolitan antenatal care clinics; to identify socio-demographic characteristics associated with unplanned pregnancy.

DESIGN, SETTING, PARTICIPANTS

Retrospective cohort study; analysis of LMUP data for women attending antenatal care booking consultations as public patients in the Sydney Local Health District, 31 December 2019 - 30 November 2020.

MAIN OUTCOME MEASURES

Proportions of women with LMUP scores indicating unplanned (0-9) or planned pregnancies (10-12); associations between planned pregnancy and socio-demographic characteristics, crude and adjusted for age, parity, and socio-economic status (Index of Relative Socioeconomic Disadvantage).

RESULTS

Of 4993 women with antenatal care bookings, the LMUP was completed by 2385 (47.8%; 1142 of 3564 women at the tertiary referral hospital [32.0%], 1118 of 1160 at the secondary hospital [96.3%]). Planned pregnancies were indicated by the total LMUP scores of 1684 women (70.6%); 1290 women (59.1%) reported no health actions in preparation for pregnancy. In multivariable analyses, planned pregnancies were more likely in all age groups than for women aged 24 years or younger (30-34 years: adjusted odds ratio [aOR], 2.54; 95% confidence interval [CI], 1.76-3.66; 35-39 years: aOR, 2.91; 95% CI, 1.95-4.33). The likelihood of planned pregnancy declined with increasing parity (v no previous births: three previous births: aOR, 0.25; 95% CI, 0.16-0.40; four or more previous births: aOR, 0.10; 95% CI, 0.05-0.19).

CONCLUSION

Seven in ten women who completed the LMUP had planned their pregnancies, but fewer than half had undertaken health-related actions prior to conceiving. Higher parity was associated with unplanned pregnancy, indicating the importance of postpartum contraception advice. Overcoming barriers to implementing the LMUP more widely would enhance preconception health monitoring.

Women's preconception health in England: a report card based on cross-sectional analysis of national maternity services data from 2018/2019

OBJECTIVE

To present the first national-level report card on the state of women's preconception health in England.

DESIGN

Cross-sectional population-based study.

SETTING

Maternity services, England.

POPULATION

All pregnant women in England with a first antenatal (booking) appointment recorded in the national Maternity Services Dataset (MSDS) from April 2018 to March 2019 (n = 652 880).

METHODS

We analysed the prevalence of 32 preconception indicator measures in the overall population and across socio-demographic subgroups. Ten of these indicators were prioritised for ongoing surveillance based on modifiability, prevalence, data quality and ranking by multidisciplinary UK experts.

RESULTS

The three most prevalent indicators were the proportion of the 22.9% of women who smoked 1 year before pregnancy who did not quit smoking before pregnancy (85.0%), those who had not taken folic acid supplementation before pregnancy (72.7%) and previous pregnancy loss (38.9%). Inequalities were observed by age, ethnicity and area-based deprivation level. The ten indicators prioritised were not taking folic acid supplementation before pregnancy, obesity, complex social factors, living in the most deprived areas, smoking around the time of conception, overweight, pre-existing mental health condition, pre-existing physical health condition, previous pregnancy loss and previous obstetric complication.

CONCLUSIONS

Our findings suggest important opportunities to improve the state of preconception health and reduce socio-demographic inequalities for women in England. In addition to MSDS data, other national data sources that record further and possibly better quality indicators could be explored and linked to build a comprehensive surveillance infrastructure.

Exploring Health Behaviours, Attitudes and Beliefs of Women and Men during the Preconception and Interconception Periods: A Cross-Sectional Study of Adults on the Island of Ireland

Preconception health is increasingly seen as a key target for improving population health in the UK and Ireland, yet little is known about the attitudes and beliefs of adults regarding preconception care strategies. This online cross-sectional survey aimed to explore the health behaviours, attitudes and beliefs of adults of reproductive age in regard to preconception health and care. The survey was developed by reviewing the previous literature and engaging with those from the target group. It is one of the first surveys to assess the attitudes and beliefs of adults of reproductive age across the Island of Ireland regarding preconception health and care. Results from 386 individuals with a mean age of 29.9 ± 10.3 years were included. A variety of health behaviours, attitudes and beliefs were investigated, with differences being identified between women and men and between participants with or without children (i.e., in the preconception or interconception stage). The majority of respondents held beliefs that preconception care was important, but there was greater emphasis on women than men in terms of the need to engage in health-promoting preconception health behaviours. This study highlights the need to improve preconception health awareness in women and men in the preconception and interconception stage. Findings indicate that efforts to improve preparation for pregnancy among adults of childbearing age are needed, to ensure optimal engagement in preconception health behaviours, with efforts being tailored based on sex and parental status.

Preconception health and care policies, strategies and guidelines in the UK and Ireland: a scoping review protocol

INTRODUCTION

Preconception care can significantly improve maternal and infant outcomes, and thus optimise intergenerational health. The aims of this scoping review are to (1) provide an up-to-date summary of preconception health and care strategies, policies, guidelines, frameworks and recommendations across the UK and Ireland and (2) explore preconception health and care services and interventions in Northern Ireland as a case study.

METHODS AND ANALYSIS

This scoping review of grey literature will be conducted as per the Scoping Review Methods Manual by the Joanna Briggs Institute and the Arksey-O'Malley framework for scoping studies, and reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Searches were conducted on Google Advanced Search, OpenAire, NICE, ProQuest and relevant public health websites in May 2022. Only results published, reviewed or updated between January 2011 and the time of the searches (May 2022) were considered for inclusion. In addition, searches on interventions and services provided in Northern Ireland will be supplemented by consultations and audits with key stakeholders to validate findings, identify other potentially eligible resources and ensure breadth of coverage. Data will be extracted into Excel and coded using NVivo, and ≥10% of the data will be double-coded. A narrative approach with content analysis highlighting key themes and concepts will be used to report findings.Throughout the research cycle, members of the wider public will be involved and engaged with to provide feedback.

ETHICS AND DISSEMINATION

Ethical approval is not required as analyses will be conducted on data available in the public domain. Findings will be shared with relevant stakeholders with the aim to inform future research, practice and decision-making, and disseminated through a peer-reviewed publication, conference presentations and infographics. Dissemination plans will be informed by the 'Healthy Reproductive Years' patient and public involvement and engagement advisory panel.

Knowledge, attitudes and behaviours surrounding preconception and pregnancy health: an Australian cross-sectional survey

OBJECTIVE

To understand Australian women's knowledge, attitudes and behaviours surrounding preconception and pregnancy health and their preferences for information about these periods.

DESIGN

Cross-sectional survey.

SETTING

Making healthy changes can optimise preconception and pregnancy outcomes. Clinical practice guidelines inform preconception and pregnancy care in Australia. Women often have access to multiple sources of information on reproductive and pregnancy health.

PARTICIPANTS

Women of reproductive age were asked to complete a web-based survey. The survey development was informed by preconception guidelines, consensus statements and the national pregnancy care guidelines. The survey was distributed through social media, local and national networks from 2017 to 2018.

RESULTS

Completed surveys were received from 553 women.The majority (80.4%) had high educational attainment. Checking immunisation status and ensuring good mental health were rated as equally important actions both preconception (65%) and during pregnancy (78%). Limiting sedentary activities was not rated as an important action to take either preconception (36%), or during pregnancy (38%). Although women have good knowledge about the impact of weight on their own health outcomes (eg, gestational diabetes), there was less knowledge about adverse outcomes for babies like stillbirth and preterm birth. Women access many sources for reproductive health information, however, the most trusted source was from healthcare professionals.

CONCLUSION

Most women of reproductive age in Australia have knowledge of the key health recommendations for preconception and pregnancy. However, there are gaps related to lifestyle behaviours particularly connected to weight gain and outcomes for babies. There is a strong preference to receive trusted information from healthcare providers through multiple resources.

Addressing reproductive health needs across the life course: an integrated, community-based model combining contraception and preconception care

Prevention of pregnancy (contraception) and preparation for pregnancy (preconception care) are services that most people need during their reproductive life course. Despite increased attention, and growing recognition that health before pregnancy is crucial to addressing disparities in maternity outcomes, service provision is far from routine. We bring together evidence from the literature, new quantitative and qualitative data on women's preferences, and case studies of existing practice, to develop an integrated, community-based model that synthesises reproductive life planning, contraception, and preconception care. Our model provides a holistic, life course approach, encompassing school-based education, social media, and national campaigns, and highlights the need for training and system-level support for the range of health-care professionals who can deliver it. This high-level model can be adapted across settings, leading to a step change in the provision of preconception care in the community with consequent improvements in health and wellbeing, and reductions in inequalities at population level.

A conceptual framework for characterising lifecourse determinants of multiple long-term condition multimorbidity

Objective

Social, biological and environmental factors in early-life, defined as the period from preconception until age 18, play a role in shaping the risk of multiple long-term condition multimorbidity. However, there is a need to conceptualise these early-life factors, how they relate to each other, and provide conceptual framing for future research on aetiology and modelling prevention scenarios of multimorbidity. We develop a conceptual framework to characterise the population-level domains of early-life determinants of future multimorbidity.

Method

This work was conducted as part of the Multidisciplinary Ecosystem to study Lifecourse Determinants and Prevention of Early-onset Burdensome Multimorbidity (MELD-B) study. The conceptualisation of multimorbidity lifecourse determinant domains was shaped by a review of existing research evidence and policy, and co-produced with public involvement via two workshops.

Results

Early-life risk factors incorporate personal, social, economic, behavioural and environmental factors, and the key domains discussed in research evidence, policy, and with public contributors included adverse childhood experiences, socioeconomics, the social and physical environment, and education. Policy recommendations more often focused on individual-level factors as opposed to the wider determinants of health discussed within the research evidence. Some domains highlighted through our co-production process with public contributors, such as religion and spirituality, health screening and check-ups, and diet, were not adequately considered within the research evidence or policy.

Conclusions

This co-produced conceptualisation can inform research directions using primary and secondary data to investigate the early-life characteristics of population groups at risk of future multimorbidity, as well as policy directions to target public health prevention scenarios of early-onset multimorbidity.

Preconception exposures and adverse pregnancy, birth and postpartum outcomes: Umbrella review of systematic reviews

BACKGROUND

Preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, the reports, statements and guidelines of national and international health organisations vary in what they recommend individuals should monitor, avoid, reduce or practise in the preconception period.

OBJECTIVES

To synthesise and evaluate the evidence across systematic reviews for associations between exposures before conception and adverse pregnancy, birth and postpartum outcomes.

DATA SOURCES

MEDLINE, Embase, Epistemonikos (to May 2020) and reference lists of included reviews, without language or date restrictions.

STUDY SELECTION, DATA EXTRACTION AND SYNTHESIS

Systematic literature reviews of observational and/or interventional studies reporting associations between preconception exposures in women and/or men of reproductive age and pregnancy, birth or postpartum health outcomes were included. The methodological quality of reviews and the certainty of the evidence underlying each exposure-outcome association were assessed using AMSTAR 2 and the GRADE approach.

RESULTS

We identified 53 eligible reviews reporting 205 unique exposure-outcome associations. Methodological quality was generally low with only two reviews rated as 'high' quality and two as 'moderate'. We found high-certainty, randomised trial evidence that maternal folate supplementation reduces the risk of neural tube defects and anomaly-related terminations. Moderate-certainty, observational evidence was found that maternal physical activity is associated with reduced risk of pre-eclampsia and gestational diabetes, and that paternal age of ≥40 years and maternal body mass index (BMI) and interpregnancy weight gain are associated with increased risk of various adverse pregnancy and birth outcomes. Low- and very low-certainty evidence was found for other associations.

CONCLUSIONS

Clinicians and policymakers can be confident that maternal folate supplementation should be encouraged during the preconception period. There is moderate certainty in the evidence base that maternal physical activity, BMI and interpregnancy weight gain and advanced paternal age are important preconception considerations. High-quality research is required to better understand other exposure-outcome associations.