A recent opinion article in the New York Times Sunday Review (Pregnant, Obese … and in Danger) highlights the dangers of obesity in pregnancy and childbirth. The article’s author, obstetrician and gynecologist Claire A. Putnam, states that: “Over two-thirds of adults and about one-third of children in America now are overweight or obese. An obese pregnant woman is more likely to have a very large baby, weighing roughly nine pounds or more. And babies of obese mothers are more likely to grow up to become overweight or obese themselves. Maternal obesity causes more immediate problems as well. Obese pregnant patients are more likely to have elevated blood pressure, gestational diabetes and babies with birth complications. They are more likely to need cesareans. And they are more likely to have serious complications from the surgery, such as infections, hernias or life-threatening bleeding.”
But what about babies born to obese mothers? In addition to birth complications, are there other consequences for these babies? Unfortunately, the answer is yes. Maternal obesity is linked to several adverse health effects in the offspring — and these effects may persist into adulthood. Babies born to obese mothers have increased lifelong risk of obesity, type-2 diabetes, high blood pressure, heart disease, asthma, and other disorders that involve the immune system. Indeed, results from a recent study show that changes in the immune system are already detectable at birth.
For the study, researchers analyzed umbilical cord blood samples of infants born to mothers grouped in lean, overweight and obese categories. These three categories were established on the basis of the body mass index (BMI) — the BMI is a measure of body fat, and is indicated with a number calculated from height and weight. A mother was considered overweight if her BMI was 25 to 29.9, and obese if her BMI was 30 or higher. The researchers found that pre-pregnancy maternal weight has a significant impact on the immune system of the neonate.
Ilhem Messaoudi, lead author of the study, said in a press release: “We found that very specific immune cells in circulation — monocytes and dendritic cells — isolated from babies born to moms with high BMI were unable to respond to bacterial antigens compared to babies born to lean moms. Such babies also showed a reduction in ‘CD4 T-cells.’ Both of these changes could result in compromised responses to infection and vaccination.”
The researchers also found that eosinophils — cells that play a role in allergic response and in the pathogenesis of asthma — were significantly reduced in the umbilical cord blood of babies born to obese mothers. One potential explanation for these observations is that these cells have already moved into the lungs, which could explain the increased incidence of asthma observed later in life in children born to obese mothers.
Messaoudi added that the immune system changes detected in babies of obese mothers could influence the response of these babies to vaccination and to asthma-inducing environmental antigens. He said: “As we know, in the first two years of life, children typically receive plenty of vaccines. The questions that arise are: Are the responses to vaccines in infants born to obese moms also impaired in the first two years of life? Should we change how often we vaccinate children born to obese moms? Should we change practices of how much and how often we vaccinate?” Messaoudi sees the study results as a launching point for further studies and a call to action.
During prenatal visits, doctors talk to pregnant mothers about smoking, recreational drug use, and alcohol. However, they should also talk about weight and weight management. In addition, as Claire A. Putnam states in her opinion article: “Above all, we need to end the taboo against talking frankly about obesity. Doctors need to be sensitive and nonjudgmental, and patients should not take offense, especially when their health, and their children’s health, is at stake.”