Maternal obesity, weight gain increase risk for CRC among ad
In utero events such as maternal obesity and weight gain increased the risk for colorectal cancer development among adult offspring, according to research published in Gut.

To investigate the association between maternal obesity and weight gain with the development of CRC in offspring, researchers analyzed data from records of 18,751 live births among 14,507 mothers from the Child Health and Development Studies prospective cohort. Medical records informed investigators about mothers’ clinical characteristics 6 months prior to pregnancy through delivery; the California Cancer Registry identified CRC diagnoses through 2019 among adult offspring.

Height and weight reported at enrollment or during a first prenatal visit were used to calculate mothers’ BMI, which was then classified into one of three categories: underweight (< 18.5 kg/m2) or healthy (18.5-24.9 kg/m2); overweight (25-29.9 kg/m2); or obese ( 30 kg/m2).

Over 738,048 person-years of follow-up, CRC development occurred in 68 offspring with 48.5% of diagnoses occurring in offspring aged younger than 50 years. Compared with healthy maternal weight, maternal overweight and maternal obesity was associated with CRC development in offspring with incidence rates of 16.2 per 100,000 among offspring of obese mothers, 14.8 per 100,000 among offspring of overweight mothers and 6.7 per 100,000 among offspring of underweight and healthy weight mothers.

Early weight gain was measured by pounds gained per week through 32 weeks gestation. Total weight gain was the difference between the mother’s last predelivery weight and the weight recorded at the first prenatal visit.

While early weight gain was not associated with CRC, researchers noted an elevated association in the highest quartile of weight gain of 1.25 pounds per week. Total weight gain was linked to an increased risk for CRC in offspring.

“In utero events – or events in early life – are important risk factors for CRC and may contribute to the alarming increase of CRC in young adults,” researchers concluded. “This study adds to the well-established evidence on the health consequences of obesity and suggests that obesity prevention should begin before birth.”