The health of both mom and dad are key to a healthy pregnancy and birth, new research finds.
In the study of nearly 786 000 births, researchers found that dads who weren't in the best of health were more likely to have preterm and low birth weight infants who spent time in the neonatal intensive care unit (NICU).
"The study suggests that a father's health before conception should be considered, as it can affect the outcome of the pregnancy for both the child and mother," said lead researcher Dr Alex Kasman. He's a resident physician in the department of urology at Stanford University Hospital in Stanford, California.
Because the study looked at data retrospectively, it can't prove that the father's health caused these medical problems, only that they seem to be associated.
Specifically, fathers with conditions such as high blood pressure, obesity, diabetes, cancer or depression had 19% higher odds of having a preterm infant, 23% higher odds of having a low birth weight infant and 28% higher odds of having an infant who needed a stay in the NICU, the researchers found.
Also, the women whose partners were in poor health were more likely to have pregnancy complications, such as gestational diabetes or preeclampsia, the findings showed.
It's not known exactly how a father's health contributes to the health of a newborn, but Kasman speculated that several factors might be at play.
"A father contributes half the genome and health can impact expression of genes, so it is reasonable to hypothesise that conditions that make a father healthy, or not, may impact these genes," he said.
Also, a father's health may have negative effects on the health of the placenta, which can lead to changes in the baby's outcome, Kasman noted.
Evidence in previous studies found poor health can negatively affect the quality of sperm in the same way as environmental exposures to smoking and toxins do, he added.
Diabetes and high blood pressure
It's also possible that genetics may be a factor, but that's not certain, Kasman said.
"While a couple with an unhealthy father and mother may have a higher chance of pregnancy complications, they can certainly still have a healthy baby," he stressed. "However, the more a couple looks after their health, the higher the odds of having a healthy baby."
Dr Rahul Gupta, chief medical and health officer at the March of Dimes, said it is possible that the father's health is a hint that the mother, too, may be in poor health.
For example, an obese man may be more likely to be with an obese woman, so the health consequences of obesity – such as diabetes and high blood pressure – may affect both partners, he suggested.
Gupta also agreed that the quality of the sperm can be affected by the health of the father and have an impact on the baby.
Shape up before conceiving
To help parents have a healthy baby, prenatal care needs to involve both parents, he said.
"We have done a fair job of focusing on prenatal care for mothers. We have improved access to care through expanded Medicaid – we're not doing great, but we're doing better than we have in the past. Where we can still do better is to involve the father before and during pregnancy," Gupta said.
Involving both parents in prenatal health has the potential to lead to healthier babies, he explained.
"It's time for both the mother and father to shape up, before conceiving the child but also during pregnancy," Gupta said.
The report was published in the journal Fertility and Sterility.
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