Maternal obesity and metabolic risk to the offspring: why lifestyle interventions may have not achieved the desired outcomes

Abstract

Obesity during pregnancy is associated with an increased risk of short- and long-term metabolic dysfunction in the mother and her offspring. Both higher maternal pregravid body mass index (kg m−2) and excessive gestational weight gain (GWG) have been associated with adverse pregnancy outcomes such as gestational diabetes, preeclampsia and fetal adiposity. Multiple lifestyle intervention trials consisting of weight management using various diets, increased physical activity and behavioral modification techniques have been employed to avoid excessive GWG and improve perinatal outcomes. These randomized controlled trials (RCTs) have achieved modest success in decreasing excessive GWG, although the decrease in GWG was often not within the current Institute of Medicine guidelines. RCTs have generally not had any success with decreasing the risk of maternal gestational diabetes (GDM), preeclampsia or excessive fetal growth often referred to as macrosomia. Although the lack of success for these trials has been attributed to lack of statistical power and poor compliance with study protocols, our own research suggests that maternal pregravid and early pregnancy metabolic condition programs early placenta function and gene expression. These alterations in maternal/placental function occur in the first trimester of pregnancy prior to when most intervention trials are initiated. For example, maternal accrural of adipose tissue relies on prior activation of genes controlling lipogenesis and low-grade inflammation in early pregnancy. These metabolic alterations occur prior to any changes in maternal phenotype. Therefore, trials of lifestyle interventions before pregnancy are needed to demonstrate the safety and efficacy for both the mother and her offspring.

‘Because the baby asks for it’: a mixed-methods study on local perceptions toward nutrition during pregnancy among marginalised migrant women along the Myanmar–Thailand border

“…Continued research on pregnant women nutrition along the border could produce easy-to-understand, culturally and contextually specific information materials to counsel women presenting to ANC about healthy GWG [26,27,58]. However, recent analyses suggest that such lifestyle measures are of modest benefit during pregnancy [34,59,60] and change will likely require policy interventions to improve access to healthy foods along the border to influence pre-conception maternal nutrition [61]. Similar upstream interventions should focus on accessing and educating women prior to conception, as pre-conception care is exceedingly rare in these communities [55].…”

Maternal Gestational and Postdelivery Weight Gain and Child Weight

“…Also, interventions before pregnancy remain important, because maternal prepregnancy BMI may be even more strongly related to childhood BMI than GWG. 25,26 Because childhood BMI is known to track into adulthood, 27 and the cardiovascular consequences of adult overweight are clear, 28 GWG may have important implications for future cardiovascular health.…”

Why it is critical to address the challenge of maternal obesity

“…Long-term follow up of children from studies of this type are awaited. That this is well received among women has been shown (9).…”

“…The more pronounced adverse effects of marked obesity may all be associated with an unfavorable metabolic milieu in early gestation. Therefore interventions beginning in the second trimester might be too late and last for too short a time to overcome the negative impact of an early dysmetabolic intrauterine environment (9). Interventions are also by themselves complex and depend not only on the time in pregnancy when they are applied, but in this case on factors such as intensity levels of physical activity, on individual compliance or motivation, and related environmental situations.…”

“…It may also be link to increased stillbirth rates (1,9). Stabilizing interpregnancy weight appears to be an important target for reducing adverse perinatal outcome in a second pregnancy.…”