Paternal weight influences child size at birth, study finds

A study carried out with 89 pairs of fathers and children showed that there is an association between paternal excess weight and the baby’s birth weight. The higher the father’s body mass index (BMI, that is, weight/height ratio), the lower the newborn’s.

The results, disclosed node International Journal of Obesityreinforce the idea that anthropometric issues are not exclusively the responsibility of mothers and that maintaining a healthy lifestyle should also be a concern for men before conceiving a baby.

“Much is said and there are many studies about the relationship between the baby’s development and maternal health, including issues such as excess weight in the pre-pregnancy and gestational period, but the fact is that the health of the parents also has a great impact on the development both fetally and after the baby is born. Our study was the first carried out with Brazilian families to show that the higher the father’s BMI, the lower the baby’s birth weight. And it highlights the importance of the father in matters of health and development of the baby”, highlights Mariana Rinaldi Carvalho, FAPESP scholarship holder and co-author of the article.

A baby’s birth weight is considered an important predictor of health not only in childhood, but throughout adulthood. In addition to the increased risk of death, several studies have already shown that babies born with low (or high) weight may develop non-communicable diseases throughout their lives, such as cardiovascular diseases, type 2 diabetes and some types of cancer.

The work, carried out by researchers from the Faculty of Medicine of Ribeirão Preto at the University of São Paulo (FMRP-USP), is the development of a clinical study largest supported by FAPESP, which evaluated the effectiveness of nutritional counseling in 350 overweight pregnant women treated in Basic Health Units (UBS).

“In studies conducted among pregnant women, we noticed that there was a missing component in the equation that involves the maternal lifestyle and the newborn. Therefore, we aimed to analyze the effect of paternal anthropometry on fetal development”, says Daniela Saes Sartorelli, professor at the Department of Social Medicine at FMRP-USP who supervised Carvalho’s doctoral study.

The group will also analyze the effect of paternal diet on neonatal anthropometry and adiposity. Parameters such as the consumption of ultra-processed foods and the quality of fat in the paternal diet will be considered.

Public health

Maternal excess weight is considered a public health issue. Several studies have already shown that excessive weight gain during pregnancy exposes both the woman and the baby to increased health risks in the short and long term.

In the mother, it increases the risk of gestational diabetes, hypertension, pre-eclampsia and cesarean sections. In childhood, there is a high probability that, in the short term, babies will be born with high or low weight. In the long term, there is an increased risk of developing obesity and associated diseases, such as type 2 diabetes or high blood pressure, at an early age.

If in the case of mothers there is a direct relationship via the placenta and other cells between obesity and fetal development, paternal excess weight can lead to some epigenetic changes (biochemical modifications in DNA that reprogram gene expression). According to Carvalho, previous studies conducted on animals had already demonstrated that some genes expressed by the father can affect fetus-placental growth.

According to the researcher, these studies showed that, even inside the mother’s womb, the fetus can suffer growth restrictions, influenced by the paternal excess weight, not reaching its genetic growth potential. Basically, paternal exposure to so-called environmental stressors in the period before fertilization, such as diet, physical activity and smoking, for example, can lead to changes in the offspring’s metabolism through epigenetic changes (read more at: agencia.fapesp.br/40302 and agencia.fapesp.br/21915 ).

“What is known so far is that these environmental stressors, such as being overweight, for example, can influence the structure and quality of sperm by altering gene expressions and influencing the child’s DNA. This influence is related to epigenetics, an area of ​​science that studies how environmental stimuli can activate or silence genes”, explains Carvalho.

“It is clear that the mother is a fundamental point and, in fact, studies show the importance of nutritional care for pregnant women. But it is necessary to shed light on the issue of paternal excess weight in the pre-conception period. The results show that, just as maternal nutritional counseling is important, parents also need to change habits before conception”, says the researcher.

The study carried out with 89 fathers and children also found that the higher the paternal BMI and waist circumference, the smaller the newborn’s head circumference. “We did not identify any anomalies or malformations, but it is an important correlation, as the baby’s head circumference is a relevant growth parameter. However, we still need new studies to assess the real meaning of this finding”, says Carvalho.

Previous studies on obesity, he adds, have identified that excess weight can influence bone mineral deposition in newborns. “We emphasize that in this study there is a limitation: we did not have access to information on how long the women were in labor [em caso de parto vaginal]. And we know that head circumference right after birth can be temporarily altered when the baby remains in the vaginal canal for a long time,” he says.

The article Relationship between paternal excessive weight and neonatal anthropometry in a clinical trial of nutritional counseling for pregnant women with overweight can be read at: www.nature.com/articles/s41366-024-01639-8# .

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This content was originally published in Paternal weight influences the size of the child at birth, finds study on the CNN Brasil website.

Source: CNN Brasil

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