The most popular IVF (in vitro fertilization) treatment used by thousands of couples could lead to their sons suffering from fertility difficulties too, new research found.
Sons whose fathers took an intro-cytoplasmic sperm injection (ICSI) to conceive were found to have low sperm counts and poor-moving sperm.
What is IVF?
In Vitro Fertilization (IVF) is a very common and popular way to solve infertility problem in men worldwide. This is a one assisted reproductive technology (ART) commonly referred to as IVF. IVF is the process of fertilization by manually combining an egg and sperm in a laboratory dish, and then transferring the embryo to the uterus.
Normally the fertilized egg (zygote) is cultured for 2–6 days in a growth medium and is then implanted in the same or another woman's uterus, with the intention of establishing a successful pregnancy.
In the year of 1977, Steptoe and Edwards successfully carried out a pioneering conception which resulted in the birth of the world's first baby to be conceived by IVF, Louise Brown on 25 July 1978, in Oldham General Hospital, Greater Manchester, UK.
The second successful birth of a test tube baby occurred in India just 67 days after Louise Brown was born. The girl, named Durga conceived in vitro using the methods of Subhash Mukhopadhyay, a physician and researcher from Kolkata.
In 2012 it was estimated that five million children had been born worldwide using IVF and other assisted reproduction techniques and in 2013, there were 37,566 embryos transferred using this type of treatment in the UK only.
The IVF treatment can be used to treat infertility with the following patients:
- Blocked or damaged Fallopian tube s
- Women with ovulation disorders, premature ovarian failure, uterine fibroid
- Male factor infertility including decreased sperm count or sperm motility
- Individuals with a genetic disorder
- Women who have had their Fallopian tubes removed
- Unexplained infertility
The new study on IVF conceived baby boys
The research Prof. André Van Steirteghemat and colleagues - from the Centre for Reproductive Medicine at the Vrije Universiteit Brussel (VUB) in Belgium - publish their research article in the journal Human Reproduction.
Intracytoplasmic sperm injection (ICSI) is a type of assisted reproductive technology. Forming a part of in vitro fertilization(IVF), it involves collecting sperm from the father and injecting it directly into the inner part of the mother's egg, in order to induce normal fertilization. The fertilized egg is then placed in the mother's womb.
Men born from ICSI were almost three times more likely to have sperm concentrations below 15 million per milliliter of semen, which is the World Health Organisation’s definition of normal.
Researchers said the findings “are not unexpected” as they had always suspected the problems that caused a man’s infertility - such as genetic factors - may be inherited by their sons.
ICSI is mainly used to treat male infertility -that is, men who have a low sperm count or abnormal sperm function. The technique allows doctors to select the best quality sperm, and injecting it directly into the egg increases the chances of fertilization.
The ICIS technique was pioneered more than 20years ago by Prof. Van Steirteghemat and team. On January 14, 1992, the first baby was born through ICSI.
As many cases of male infertility are caused by genetic defects, Prof. Van Steirteghemat and colleagues always speculated that men conceived through ICSI might inherit such defects from their fathers.
Now, speculation may have moved closer to fact,after an analysis of 54 men born through ICSI between 1992 and1996, a time when the procedure was solely used for male infertility - suggests an association between the procedure and poor sperm quantity and quality.
Decrease in sperm count and concentration
The 54 men included in the study - aged 18-22 -were identified through the UZ Brussel hospital database, and they were matched with a group of control men who had been conceived naturally.
Of the men who were conceived through ICSI, 50 of them had fathers who had male-factor infertility (two cases of combined male and female infertility, 48 cases of male infertility only). For parents of the remaining four men, the reason for their infertility was unknown.
All men were asked to provide semen samples,which were assessed for sperm quantity and quality. Blood samples were also collected for analysis, and other health checks were conducted.
The analysis revealed that men conceived through ICSI had almost half the total sperm concentration as men conceived naturally,and they showed a twofold reduction in total sperm count (semen volume multiplied by semen concentration) and total motile sperm count (the number of sperm that can reach the egg).
Furthermore, men conceived through ICSI were found to be three times more likely to have a sperm concentration below 15million per milliliter and four times more likely to have a total sperm count below 39 million per milliliter.
For reference, the World Health Organization(WHO) considers a normal sperm concentration to be 15 million per milliliter or higher.
The team's findings remained even after accounting for a number of factors that might have impacted semen quality,including age, body mass index (BMI), and genital malformations.
New study revealed 'a degree of sub-fertility has been passed on'
Prof. Van Steirteghemat and colleagues say their results suggest men conceived through ICSI may have poorer sperm quality and quantity, increasing their likelihood of fertility problems.
"These findings are not unexpected," says Prof. Van Steirteghemat. "Before ICSI was carried out, prospective parents were informed that it may well be that their sons may have impaired sperm and semen like their fathers. For all the parents, this information was not a reason to abstain from ICSI because, as they said: 'if this happens ICSI can then also be a solution for our sons.'"
"These first results from the oldest group of ICSI-conceived adults worldwide indicate that a degree of 'sub-fertility' has, indeed, been passed on to sons of fathers who underwent ICSI because of impaired semen characteristics", adds Prof. André Van Steirteghemat.
Furthermore, there is no indication that specific semen characteristics can be passed from fathers to sons through ICSI; in the study, the low sperm concentration and total motile sperm counts among ICSI-conceived men did not correlate with those of their fathers.
"The study shows that semen characteristics of ICSI fathers do not predict semen values in their sons. It is well established that genetic factors play a role in male infertility, but many other factors may also interfere. Furthermore, correlation is not the something as causation," says Prof. Van Steirteghemat.
Children conceived through IVF should be monitored properly
Scientists revealed that their results cannot be generalized to all men conceived through ICSI, as the way the technique is used has changed over the years; nowadays, it is used in most IVF procedures, even when there is no evidence that a couple's infertility is due to the man's poor semen characteristics.
Yet, Prof. Van Steirteghemat says the findings emphasize the need for research that monitors the fertility and overall health of offspring conceived using assisted reproduction techniques.
"For instance, paired analysis of samples from fathers and sons should be carried out, and we need to look at larger numbers of offspring," he adds.
"This remains a challenging project for the VUB. However, health authorities and funding agencies should provide the means to answer questions concerning the effects of genetics, mode of conception,fetal growth patterns, and birth weights on the fertility of ICSI men."
ProfessorAdam Balen, chairman of the British Fertility Society, said he was “surprised” that some causes of infertility maybe transmitted to children born by fertility treatments.
“While these young men may have lower sperm counts than the general population, they may still be able to father children without treatment and if they cannot they will have the opportunity to use the IVF/ICSI themselves,” he concluded.
Dr Alastair Sutcliffe, a paediatrician at the institute, said: 'This the first study of its kind. We don't yet know the implication of the findings because the children are very young, but we need to inform people.'
Josephine Quintavalle, from Comment on Reproductive Ethics, said ICSI was becoming the preferred option in infertility treatment because of a shortage of healthy sperm, caused by legislation requiring donors to agree to be identified to offspring in adulthood.
She said: 'Using ICSI is obviously counter-intuitive to good health and this research would demonstrate that maybe true.'
Allan Pacey, an expert in male infertility at Sheffield University and a spokesman for the British Fertility Society, said ICSI should be used 'only when absolutely necessary'.
A spokesman for the Human Fertilization and Embryology Authority, the watchdog which regulates private IVF clinics, said doctors should warn couples of the risks of treatment before they were enrolled as patients.
John Manning, an evolutionary biologist at Southampton University and one of the authors of the study, said: 'This is telling us that we should only use ICSI when it is absolutely necessary.