Obese father, small baby: how the father’s weight affects the size of the newborn and his future health

These results reinforce the idea that anthropometric issues are not the exclusive responsibility of the mother and that the father is also You should strive to maintain a healthy lifestyle during your partner’s pregnancy.

“There is much debate and research on the relationship between fetal development and maternal health, including issues such as being overweight before and during pregnancy, but The fact is that the health of the father also has a significant impact on the development of the babyboth during pregnancy and after birth. Our study is the first in which Brazilian families participate and shows that the higher the father’s BMI, the lower the baby’s birth weight, which highlights the importance of the father for the health and development of the baby”, says Mariana Rinaldi Carvalho, first author of the article and researcher at the Ribeirão Preto Faculty of Medicine of the University of São Paulo (FMRP-USP).

Key factor to predict health

Birth weight is considered a key factor in predicting health, not only in early childhood, but throughout life. Numerous research has shown that babies born with low (or high) weight are at increased risk of death and developing non-communicable diseases in later life, such as type 2 diabetes, cancer and cardiovascular disorders.

The study conducted by FMRP-USP researchers was the continuation of a clinical trial that investigated the effect of nutritional counseling intervention on weight gain in 350 overweight pregnant women attending public primary care clinics.

“Having observed that most studies on fetal and neonatal health do not take into account parental lifestylewe proposed to include paternal anthropometry as a factor that affects fetal development,” explains Carvalho’s thesis director, Daniela Saes Sartorelli, last author of the study and professor at the Department of Social Medicine at FMRP-USP.

The group plans to analyze the effect of paternal diet on neonatal anthropometry and adiposity, focusing on the consumption of ultra-processed foods and the quality of fats.

The dangers of maternal overweight

Maternal overweight is considered a public health problem and numerous studies have shown that excessive weight gain during pregnancy is a significant short- and long-term health hazard for both mother and baby. In the case of the mother, it increases the risk of gestational diabetes, hypertension and preeclampsia, which often makes a cesarean section inevitable. In the case of the baby, it increases the probability of low or high birth weight and the risk of obesity and Associated disorders such as type 2 diabetes and hypertension at an early age.

While in the case of the mother there is a direct link through the placenta and other cells between obesity and fetal development, paternal overweight can cause epigenetic alterations (biochemical changes in DNA that reprogram gene expression).

According to Carvalho, previous animal studies showed that some genes expressed by the father can affect fetoplacental growth.

Without reaching genetic power

The fetus may suffer growth restrictions influenced by paternal overweight and not reach its genetic growth potential, he explains. In summary, paternal exposure prior to conception to environmental stressors such as an unhealthy dieta sedentary lifestyle and smoking, for example, can cause metabolic disorders in offspring through epigenetic alterations.

«We now know that environmental stress factors such as being overweight can influence the structure and quality of the father’s sperm, altering gene expression and affecting the DNA of his children. This influence is related to the epigeneticsthe scientific field that studies how environmental stimuli can activate or silence genes,” says Carvalho.

Thus, he adds that “the health of the mother is obviously a key factor, and research has shown the importance of a healthy diet during pregnancy, but more attention needs to be paid to paternal overweight in the period before conception. “The results of our research show that, just as maternal nutritional advice is important, so is the need for a change in paternal habits before conception.”

The study, which involved 89 parents and babies, also found that the higher the father’s BMI and waist circumference, the smaller the baby’s head circumference at birth. «We did not detect anomalies or malformations, but the correlation is important because head circumference at birth is a key growth parameter. However, more research is needed to evaluate the real importance of this finding,” says Carvalho, who recalls that previous studies on obesity discovered that being overweight influences neonatal bone mineralization.