Over a quarter of pregnancies might end up as ectopic, in miscarriage or stillbirth if the father-to-be is unhealthy and has three or more medical conditions like obesity, diabetes, high blood pressure or high cholesterol levels, a study has revealed.
The researchers emphasised that pre-conception counselling should not forget the father, as his health may have an important impact on the pregnancy outcome.
The study, published in Human Reproduction, a peer-reviewed journal, was carried out by researchers from Stanford University School of Medicine, California, United States.
According to the study, which involved nearly a million pregnancies between 2009 and 2016 in the US, if a father was diagnosed with metabolic syndrome that includes the listed medical conditions, there was an increased risk of the mother losing the pregnancy.
It noted that, compared to men who had none of the components of metabolic syndrome, the risk of pregnancy loss increased by 10 per cent, 15 per cent and 19 per cent respectively for men with one, two or three or more components.
According to Mayo Clinic, metabolic syndrome is a cluster of conditions that occur together, increasing the risk of heart disease, stroke and type 2 diabetes.
It noted that the conditions include increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol level.
Speaking further on the finding, lead researcher and Associate Professor, Michael Eisenberg, said it had been known that the health of mothers has an impact on the developing foetus and events at the time of birth, but that the health of fathers never received attention.
He explained that the study is the first to suggest that pregnancies sired by men with increasing numbers of medical conditions are at higher risk of ending in miscarriage, ectopic pregnancy or stillbirth.
“In the group of men we studied, the risk of losing the pregnancy was 17 per cent in couples where the father had no components of the metabolic syndrome.
“But it increased to 21 per cent in couples where the father has one metabolic syndrome component, 23 per cent where he has two, and 27 per cent where he has three or more.
“While this study can’t prove that poor paternal health is a cause of pregnancy loss, it shows there is an association.”
Reacting to the findings, an Obstetrician and Gynaecologist, Dr. Kelvin Madu, said the health of the father doesn’t in all cases impact on the pregnancy, especially in the case of ectopic pregnancy, which has more to do with implantation.
While speaking with our correspondent, Madu, who heads OAR Medical Centre in Egbeda, Lagos, said ectopic pregnancy has more to do with the mother than father-to-be.
He explained that ectopic pregnancy, also known as extrauterine pregnancy, occurs when a fertilised egg grows outside a woman’s uterus, or somewhere else in the belly.
“It can be life-threatening and requires urgent medical intervention. In more than 90 per cent of ectopic cases, the egg implants in a fallopian tube.
“Usually, an ectopic pregnancy happens within the first few weeks of pregnancy and the woman might not even be aware that she is pregnant.
“It can rupture the fallopian tube and can cause major pain, with or without severe bleeding,” Madu said.
He, however, said some underlying medical conditions and lifestyle can actually lead to low sperm count (oligospermia).
“Certain lifestyles like cigarette smoking, use of illicit drugs, unhealthy diet, alcohol intake, use of illicit drugs and sleep disturbances can impact negatively.
“Behaviour modification can counter the negative effects these choices could have on individuals in the long run,” he said.
Another physician, Dr. Rotimi Bakare, said the first study doesn’t always apply, but noted that genetic and blood group incompatibility (Rhesus factor) can affect the outcome of a pregnancy.
“The health of a father, especially when it comes to having a transmittable infection, can also play a vital role in pregnancy outcome.
“A father can pass an infection to the mother, and this in turn can be passed to the developing foetus,” Bakare said.
On how the study was conducted, the researchers said they analysed data from US insurance claims covering 958,804 pregnancies.
They explained that to establish the impact of metabolic syndrome, they gathered information on other medical conditions such as chronic obstructive pulmonary disease, depression and heart disease.
The team also calculated the burden of chronic disease for all patients, which included age and medical history of problems such as heart failure, heart attack, diseases of the blood vessels, kidney and liver disease, cancer, stroke and dementia.
The researchers said they then adjusted their calculations to take account of other factors that could affect pregnancy, particularly, mother’s age, health, weight, and whether or not the father and mother smoked.
“A total of 4.6 per cent of men in the study were aged over 45 years and 23.3 per cent had at least one component of metabolic syndrome prior to conception.
“There were 785,809 live births and 172,995 pregnancies (22%) lost to ectopic pregnancy, miscarriage or stillbirth during the period of the study.
“As expected, pregnancy losses increased with the mother’s age and the number of other medical conditions she had.
“However, the association with the health of the father and pregnancy loss remained.
“The risk of losing a pregnancy also increased with the age of the father.
“The mechanisms by which the father’s health might affect the risk of pregnancy loss are not known,” they said.
Eisenberg, the lead researcher, noted that his team hypothesised that the father’s health and lifestyle could adversely affect the genetic make-up and expression in the sperm, and that this may alter how well the placenta functions.
“If the placenta isn’t working properly, then this could lead to the pregnancy losses that we observed.
“For instance, we know already that paternal smoking and diet can affect sperm quality,” he added.
Eisenberg, however, noted that there are limitations to the study, which include potential lack of detail and accurate diagnoses inherent in obtaining information from insurance claims databases, and pregnancy losses that did not result in a medical claim.
He said, “For instance, those in early miscarriage were not included in the database, although the frequency of miscarriages, still births and ectopic pregnancies observed in the study were similar to estimates for the general US population.
“The findings include only privately insured and employed parents, and the findings might not be generalisable to other populations.
“Information on important factors such as socio-demographic status, race and substance abuse, was incomplete.”
He, however, said there is a need for confirmatory studies, adding, “Hopefully, paternal health can be more integrated into future studies.
“In addition, investigations that target the possible mechanisms will help to better understand the associations we found.”
According to an article published in the Washington Post, titled ‘What men eat and drink may affect their babies’ health, the paternal role in producing a healthy baby is rarely considered, but that emerging science indicates that fathers play a more significant role in pregnancy outcomes than previously thought.
It noted that low sperm count or damaged sperm actually have an impact on pregnancy outcomes.
“For instance, we know that sperm helps to determine how well the placenta forms — a key factor in foetal development — and that impaired sperm dramatically increases the likelihood of miscarriage, possibly because it is known to contain high levels of free radicals.
“Moreover, thanks to the science of epigenetics, we are learning that human sperm may carry “biological memories” of abnormalities that can be transferred to offspring,” it stated.