Risk of early death and hospitalisation for a cardiovascular event was significantly higher in the grown-up children of obese mothers compared with those whose mothers had a normal BMI, a study from Scotland has shown.

The study, published in the BMJ, was a record linkage cohort analysis using birth records from the Aberdeen Maternity and Neonatal Databank linked to the General Register of Deaths, Scotland, and the Scottish Morbidity record systems. It included 28,540 mothers and their 37,709 offspring with birth records from 1950 to the present day.

Of the mothers, 5,993 (21%) were overweight (BMI 25-29.9) and 1,141 (4%) were obese (BMI ≥ 30).

The primary outcome measure was death and hospital admission for cardiovascular events up to 1 January 2012 in offspring aged 34-61 years; a follow-up of 1,323,275 person-years.

Maternal BMI was calculated from measurements made at the first antenatal visit. The effect of maternal obesity on the outcomes of offspring was analysed in underweight, overweight, and obese categories of maternal BMI compared with children of mothers with normal BMI. The results were adjusted for maternal age at delivery, socioeconomic status, sex of offspring, current age, birthweight, gestation at delivery, and gestation at measurement of BMI.

After adjustment, all cause mortality was increased in the offspring of obese mothers compared with those whose mothers had a normal BMI, hazard ratio (HR) 1.35 (95% CI:1.17-1.55).

In adjusted models, offspring of obese mothers also had an increased risk of hospital admission for a cardiovascular event, HR 1.2 (95% CI:1.06-1.57) compared with those of mothers with a normal BMI.

The authors consider that the mechanism underlying these findings could centre around increased circulating levels of inflammatory cytokines, non-esterified fatty acids and increased insulin resistance resulting in an increased nutrient supply to the fetus with compensatory fetal hyperinsulinaemia and increased fetal adipose.

This could result in permanent changes in appetite control, neuroendocrine functioning, and energy metabolism in the offspring, leading to an increase in adult adipose formation and the accompanying cardiovascular risk factors.

The authors conclude that maternal obesity is associated with an increased risk of premature death in adult offspring.

One in five women in the United Kingdom are classified as obese at antenatal booking. It would seem that our efforts to tackle obesity need to continue at all levels from public health and government initiatives to the face-to-face consultation.

In particular specific strategies are required to optimise weight before pregnancy.

Dr Peter Savill

• Reynolds RM, Allan KM, Raja EA et al. Maternal obesity during pregnancy and premature mortality from cardiovascular event in adult offspring: follow-up of 1323 275 person years. BMJ 2013;347: f4539