Unhealthy Fathers-to-be Could Raise the Risk of Pregnancy Loss

By Linda Carroll

December 21, 2020

(Reuters Health) - The risk of pregnancy loss may be greater when prospective fathers have chronic conditions, such as obesity, diabetes, high blood pressure or high cholesterol, a new study finds.

The more health conditions a man has, the higher the risk, researchers report in Human Reproduction. In the analysis, pregnancy loss was most likely when fathers-to-be had three or more components of metabolic syndrome, which increased risk by 19% compared to when men had none of these conditions.

"The main point is that paternal preconception health matters," said study coauthor Dr. Michael Eisenberg, an associate professor in the department of urology and director of male reproductive medicine and surgery at the Stanford University School of Medicine in California. "Fertility is a team sport. But most counseling has developed to focus on the health of the mother. This shows the same applies to the father."

Dr. Eisenberg doesn't know yet how the father's preconception health might be impacting the health of pregnancies, but he suspects that the mechanism has to do with epigenetics as opposed to genetics. "If something is wrong with the epigenetics of the sperm, that could lead to poor quality embryos, poor quality placentas, or an entire pregnancy loss," he said.

To take a closer look at the possibility that paternal health could be a risk factor for pregnancy loss, Dr. Eisenberg and his colleagues turned to the Marketscan Research database, which provides U.S. data on reimbursed healthcare claims on inpatient and outpatient encounters and covers over 153 million individuals privately insured through employer-sponsored health insurance and Medicare supplemental coverage.

Included in the analysis were claims data from 2007 to 2016 for 956,804 pregnancies in which the women were aged 20 to 45. Pregnancy outcomes analyzed in the study included live birth, stillbirth, ectopic pregnancy and spontaneous abortion.

The average paternal age was 35.3 and the average maternal age was 33. A total of 4.6% of the men were older than 45. The average observation period of the men was 3.9 years, while for women it was 3.7 years.

The researchers looked at comorbidities in both parents. For men, these included components of metabolic syndrome such as hypertension, hyperlipidemia, obesity and diabetes, as well as heart disease, COPD, depression, and other common illnesses.

Overall, 23.3% of men had at least one component of metabolic syndrome prior to conception. A total of 785,809 pregnancies resulted in live births, while there were 172,995 pregnancy losses.

There was a higher risk of pregnancy loss with increasing numbers of paternal components of metabolic syndrome. The highest risk of pregnancy loss was among men with three or more components (Relative Risk: 1.19). With one or two components, RR was 1.10 and 1.15, respectively.

Dr. Eisenberg notes that other paternal health issues, such as smoking, have also been linked to poor pregnancy outcomes.

When it comes to pregnancy loss, the big focus has been on women, Dr. Eisenberg said. "I think a lot of the time an absence of information has to do with mothers being blamed for stuff," he added. "There's no doubt that the mother is very important, but the father is too."

Clinicians should remember this when counseling couples, Dr. Eisenberg said, adding "the take-home point from this study is that fathers are important as well and we should think about both members of the couple during this fertility journey."

SOURCE: https://bit.ly/3oXWx50 Human Reproduction, online December 18, 2020.