Insights from outside BJOG

Abstract

The traditional measures of perinatal outcomes are mortality rates, Apgar scores, delivery age and weight, but increasingly, more sophisticated criteria of pregnancy outcomes are being explored. This incorporates longitudinal studies that indicate that maternal socio-economic factors profoundly influence childhood and long-term development. The initial concept – that the intrauterine environment could affect the health of the adult – was hypothesised by Barker (BMJ 1995;311:171–4). He postulated that fetal malnutrition could give rise to heart disease in later life, which opened the way to more detailed investigations into the fetal origins of health and disease. His thesis was that the conceptus has ‘in its genes a generative programme for making a person’ and this programming could be influenced by the mother’s wellbeing. The question now being posed is: just how intimately is her uterine milieu influenced by her socio-economic status? Obstetric records and information from national databanks are able to detect the effects of teratogens, nutrition, metabolic disturbances, infections, drugs and more subtle factors such as stress and anxiety, with these factors playing out in infancy, childhood, adolescence and adult life. Gross insults to the fetus are readily studied but less obvious influences during gestation reveal themselves as physiological outliers of cognitive, behavioural and emotional variations downstream. These in turn can be traced back to parental socio-economic status, incorporating income, education, employment, inequality, food, housing, security, neighbourhood, development and social support (Papageorghiou BJOG 2020;127:431–2). The links between broad socio-economic status and adverse pregnancy outcomes are clear (Reynolds et al. Eur J Obstet Gynecol Reprod Biol 2020; 250:86–92), but quite what in the social or economic spectrum causes the effects is difficult to elucidate. The factors impinging on the fetus can be direct, such as non-ionising radiation (Li et al. JAMA Netw Open 2020;3:e201417), or via maternal intake, or intrinsically generated by the mother’s emotions (Wu et al. JAMA Netw Open 2020;3: e1919940). Other links are generating a large volume of research publications. What is being shown is that disadvantaged women have increased exposure to air pollution (Vrijens et al. JAMA Netw Open 2020;3:e205156; and Fleisch et al. JAMA Netw Open 2020;3:e206046) or foods containing phthalates (which are known endocrine disruptors; Zhang et al. JAMA Network Open 2020;3: e202159), plus they are more likely to experience overor under-nutrition with the quality and quantity of calories they ingest affecting the blood pressure of their offspring at the age of 5 years (Cox et al. JAMA Netw Open 2020;3: e204662). There is also a strong association between socio-economic status and drugtaking, with perhaps the most alarming article entitled ‘Associations of Maternal Prenatal Drug Abuse With Measures of Newborn Brain Structure, Tissue Organisation, and Metabolic Concentrations’ (Peterson et al. JAMA Pediatr 2020; https://doi.org/10.1001/jamapediatrics.2020. 1622). The researchers from the USA trace illicit drug-taking in a high-risk population group and present evidence of the detrimental effects of cannabis, cocaine and heroin on immediate neonatal aberrations and on the child’s development at 12 months. Alcohol and tobacco use are within the maternal moral choice ambit and disadvantaged women are vulnerable in this regard. The host of links between low socioeconomic status and suboptimal neonatal outcomes do not identify a single factor nor do they propose mechanisms whereby the influences create genetic (and epigenetic) consequences. However, DNA studies show a correlation between low parental socio-economic status and short fetal telomere lengths (Martens et al. JAMA Netw Open 2020;3:e204057). This suggests a higherthan-average cell replication during the fetus’s compromised intrauterine existence, which could be explained by the conceptus attempting to achieve maturity when threatened by ‘increased oxidative stress and inflammation’. This may be operational methodology when there is accelerated cell division without physical growth (Sacchi et al. JAMA Pediatr 2020;174:772–81). However, this advanced processing comes at a cost of ‘untoward long-term outcomes, including diabetes and cardiovascular diseases, and affects cognitive, socioemotional, and behavioral domains’ (Guerby and Bujold JAMA Pediatr 2020;174:749–50). Whether it would be ethical to explore fetal wellbeing by telomere measures using non-invasive prenatal testing during gestation is debatable, but there are data that indicate remedial interventions can be successfully employed within family structures which show intergenerational promise (Hill et al. JAMA Pediatr 2020;174:764–71). Is the yoke of socio-economic deprivation on pregnant women reversible by education, reason and logic? Can appeals be made to what Immanuel Kant called each person’s ‘moral law within’ (Berwick JAMA 2020;324:225-6)? What is certain is that maternal wellbeing can affect fetal well-being, and the fetal origins of health are more nuanced than we thought.