Paternal preconception modifiable risk factors for adverse pregnancy and offspring outcomes: a review of contemporary evidence from observational studies

Influence of paternal preconception health on pregnancy, intrapartum, postpartum and early childhood outcomes: protocol for a parallel scoping review

INTRODUCTION

Preconception care is the provision of behavioural, social or biomedical interventions to women and couples prior to conception. To date, preconception research has primarily focused on maternal health, despite the male partner's contribution before birth to both short-term and long-term child outcomes. The objectives of the reviews are: (1) to identify, consolidate and analyse the literature on paternal preconception health on pregnancy and intrapartum outcomes, and (2) to identify, consolidate and analyse the literature on paternal preconception health on postpartum and early childhood outcomes.

METHODS AND ANALYSIS

A scoping review will be conducted following the Joanna Briggs Institute methodology. MEDLINE, PsycINFO, Embase, Scopus and CINAHL databases will be searched for articles published in English. Two independent reviewers will screen titles and abstracts and then full text using Covidence, with conflicts resolved by a third reviewer. Data extraction will be performed using Covidence.

ETHICS AND DISSEMINATION

Ethics approval is not required for this scoping review. Results will be published in peer-reviewed journals as well as presented at relevant national and international conferences and meetings.

Maternal pre-pregnancy BMI and reproductive health in adult sons: a study in the Danish National Birth Cohort

STUDY QUESTION

Is maternal pre-pregnancy BMI associated with semen quality, testes volume, and reproductive hormone levels in sons?

SUMMARY ANSWER

Maternal pre-pregnancy BMI was associated with an altered reproductive hormone profile in young adult sons, characterized by higher levels of oestradiol, LH, and free androgen index (FAI) and lower levels of sex hormone-binding globulin (SHBG) in sons born of mothers with pre-pregnancy overweight and obesity.

WHAT IS KNOWN ALREADY

Evidence suggests that maternal pre-pregnancy BMI may influence reproductive health later in life. Only one pilot study has investigated the association between maternal pre-pregnancy BMI and reproductive health outcomes in sons, suggesting that a high BMI was associated with impaired reproductive function in the adult sons.

STUDY DESIGN, SIZE, DURATION

A population-based follow-up study of 1058 young men from the Fetal Programming of Semen Quality (FEPOS) cohort nested within the Danish National Birth Cohort (DNBC), 1998-2019, was carried out.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In total, 1058 adult sons (median age 19 years, 2 months), born 1998-2000 by mothers included in the DNBC, participated in FEPOS. At a clinical examination, they provided a semen and blood sample, measured their testes volume, and had height and weight measured. Maternal pre-pregnancy BMI was obtained by self-report in early pregnancy. Semen characteristics, testes volume, and reproductive hormone levels were analysed according to maternal pre-pregnancy BMI categories and as restricted cubic splines using negative binomial and ordinary least square regression models. Mediation analyses examined potential mediation by the sons' birthweight, pubertal timing, fat mass, and BMI. Additional analyses investigated the role of paternal BMI in the potential associations between maternal BMI and reproductive health outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

We found no consistent associations between maternal pre-pregnancy BMI and semen characteristics or testes volume. Sons of mothers with higher pre-pregnancy BMI had higher oestradiol and lower SHBG levels, both in a dose-dependent manner. Sons of mothers with pre-pregnancy obesity (≥30 kg/m2) had higher LH levels and a higher FAI than sons born by mothers with normal pre-pregnancy BMI (18.5-24.9 kg/m2). The mediation analyses suggested that the effect of maternal pre-pregnancy BMI on higher levels of oestrogen, LH, and FAI was partly mediated by the sons' birthweight, in addition to adult fat mass and BMI measured at the clinical examination, whereas most of the effect on lower levels of SHBG was primarily mediated by the sons' own fat mass and BMI. Paternal BMI was not a strong confounder of the associations in this study.

LIMITATIONS, REASONS FOR CAUTION

This study was based in a population-based cohort with a low prevalence of overweight and obesity in both mothers and adult sons. Some men (10%) had blood for reproductive hormone assessment drawn in the evening. While several potential confounding factors were accounted for, this study's inherent risk of residual and unmeasured confounding precludes provision of causal estimates. Therefore, caution should be given when interpreting the causal effect of maternal BMI on sons' reproductive health.

WIDER IMPLICATIONS OF THE FINDINGS

Given the widespread occurrence of overweight and obesity among pregnant women, it is imperative to thoroughly examine the potential consequences for reproductive hormone levels in adult sons. The potential effects of maternal pre-pregnancy obesity on sons' reproductive hormone profile may potentially be partly avoided by the prevention of overweight and obesity in the sons.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by the Lundbeck Foundation (R170-2014-855), the Capital Region of Denmark, Medical doctor Sofus Carl Emil Friis and spouse Olga Doris Friis's Grant, Axel Muusfeldt's Foundation (2016-491), AP Møller Foundation (16-37), the Health Foundation, Dagmar Marshall's Fond, Aarhus University, Independent Research Fund Denmark (9039-00128B), and the European Union (ERC, BIOSFER, 101071773). Views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible. The authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

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 Care: A Strategic Intervention for the Prevention of Neonatal and Birth Disorders

Preconception care is a strategic intervention to improve neonatal and birth outcomes by addressing modifiable risk factors and optimizing maternal and fetal health before pregnancy. This review article examines the importance of preconception care and its impact on preventing neonatal and birth disorders. The methodology involved a comprehensive review of peer-reviewed articles, research studies, and authoritative reports. Key components of preconception care, evidence-based interventions, and their effectiveness in reducing specific neonatal and birth disorders are discussed. The review also highlights the challenges and barriers in implementing preconception care, such as lack of awareness, socioeconomic factors, health system limitations, and policy considerations. Strategies for promoting preconception care, including integration into healthcare systems, raising awareness, healthcare professional education, and collaborations are presented. The conclusion emphasizes the significance of preconception care as a strategic intervention and calls for action by healthcare providers, policymakers, and individuals to prioritize preconception care for better neonatal and birth outcomes.