We hear a lot about women’s biological clock and how age affects the chance of pregnancy.

New research shows men’s fertility is also affected by age. When dads are over 50, the risk of pregnancy complications increases.

Data from more than 46 million births in the United States between 2011 and 2022 compared fathers in their 30s with fathers in their 50s.

While taking into account the age of the mother and other factors known to affect pregnancy outcomes, the researchers found every ten-year increase in paternal age was linked to more complications.

The researchers found that compared to couples where the father was aged 30–39, for couples where the dad was in his 50s, there was a:

• 16% increased risk of preterm birth
• 14% increased risk of low birth weight
• 13% increase in gestational diabetes.

The older fathers were also twice as likely to have used assisted reproductive technology, including IVF, to conceive than their younger counterparts.

Dads are getting older

In this US study, the mean age of all fathers increased from 30.8 years in 2011 to 32.1 years in 2022.

In that same period, the proportion of men aged 50 years or older fathering a child increased from 1.1% to 1.3%.

We don’t know the proportion of men over 50 years who father children in Australia, but data shows the average age of fathers has increased.

In 1975 the median age of Australian dads was 28.6 years. This jumped to 33.7 years in 2022.

How male age affects getting pregnant

As we know from media reports of celebrity dads, men produce sperm from puberty throughout life and can father children well into old age.

However, there is a noticeable decline in sperm quality from about age 40.

Female partners of older men take longer to achieve pregnancy than those with younger partners.

A study of the effect of male age on time to pregnancy showed women with male partners aged 45 or older were almost five times more likely to take more than a year to conceive compared to those with partners aged 25 or under. More than three quarters (76.8%) of men under the age of 25 years impregnated their female partners within six months, compared with just over half (52.9%) of men over the age of 45.

Pooled data from ten studies showed that partners of older men are also more likely to experience miscarriage. Compared to couples where the male was aged 25 to 29 years, paternal age over 45 years increased the risk of miscarriage by 43%.

Older men are more likely to need IVF

Outcomes of assisted reproductive technology, such as IVF, are also influenced by the age of the male partner.

A review of studies in couples using assisted reproductive technologies found paternal age under 40 years reduced the risk of miscarriage by about 25% compared to couples with men aged over 40.

Having a male under 40 years also almost doubled the chance of a live birth per treatment cycle. With a man over 40, 17.6% of treatment rounds resulted in a live birth, compared to 28.4% when the male was under 40.

How does male age affect the health outcomes of children?

As a result of age-related changes in sperm DNA, the children of older fathers have increased risk of a number of conditions. Autism, schizophrenia, bipolar disorders and leukaemia have been linked to the father’s advanced years.

A review of studies assessing the impact of advanced paternal age reported that children of older fathers have increased rates of psychiatric disease and behavioural impairments.

But while the increased risk of adverse health outcomes linked to older paternal age is real, the magnitude of the effect is modest. It’s important to remember that an increase in a very small risk is still a small risk and most children of older fathers are born healthy and develop well.

Improving your health can improve your fertility

In addition to the effects of older age, some chronic conditions that affect fertility and reproductive outcomes become more common as men get older. They include obesity and diabetes which affect sperm quality by lowering testosterone levels.

While we can’t change our age, some lifestyle factors that increase the risk of pregnancy complications and reduce fertility, can be tackled. They include:

• smoking
• recreational drug taking
• anabolic steroid use
• heavy alcohol consumption.

Get the facts about the male biological clock

Research shows men want children as much as women do. And most men want at least two children.

Yet most men lack knowledge about the limitations of female and male fertility and overestimate the chance of getting pregnant, with and without assisted reproductive technologies.

We need better public education, starting at school, to improve awareness of the impact of male and female age on reproductive outcomes and help people have healthy babies.

For men wanting to improve their chance of conceiving, the government-funded sites Healthy Male and Your Fertility are a good place to start. These offer evidence-based and accessible information about reproductive health, and tips to improve your reproductive health and give your children the best start in life.

Karin Hammarberg, Senior Research Fellow, Global and Women’s Health, School of Public Health & Preventive Medicine, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We often use the word vagina to describe everything “down there”, but that’s not actually anatomically correct.

The vagina is the stretchy, muscular tube that connects the external genitalia, or vulva, to the cervix, which is the entrance to the uterus (womb).

Because it’s barely visible from the outside, many vagina owners wonder how long theirs is, or should be.

Worried teenagers going through puberty regularly asked “Dolly Doctor” – the medical advice column Melissa wrote for over 20 years in Dolly magazine – whether their vaginas were too small or short.

Often they were asking because inserting a tampon was difficult or painful.

The vagina is an incredibly adaptable part of the body and its length can change – across your lifetime, within the month, and with hormonal changes and sexual arousal.

Length at different life stages

Before puberty, the vagina usually measures between 5.5 and 8cm in length.

During puberty (usually between 8–13 years old), not only does the length of the vagina increase, but hormones also change the vaginal lining.

In the time of life between puberty and menopause, oestrogen levels rise and cause the lining of the vagina to thicken and soften. This is what makes the vagina moist and responsive to stimuli, such as when aroused.

By adulthood, the vagina is typically between 6.5cm and 12.5cm. This varies greatly from person to person and continues to change at different times during our lives.

What else can change the vagina’s length?

When someone has their period, generally the cervix sits in a lower position, meaning the vaginal canal is shorter. Then, after menstruation, the cervix lifts upwards again and reaches its highest point during ovulation.

The length of the vagina also changes during different reproductive stages. For example, in pregnancy the cervix sits higher up, meaning the vagina is longer.

On the other hand, menopause, along with many other impacts such as vaginal dryness, can shorten the vaginal canal.

A pelvic organ prolapse can also make the vagina shorter. This is when the pelvic floor becomes weakened and organs such as the womb or bladder bulge into the vagina.

There are also some very rare conditions that can affect the development of the vagina before birth, such as vaginal atresia, which can cause the vagina to not fully form.

What about sex?

Sex also has a large impact on vaginal length.

When someone with a vagina becomes aroused the vagina gets longer and moves the cervix further from the vaginal opening, which allows for sexual penetration.

Despite this lengthening of the vagina, contact with the cervix can still occur during sex, for example with a sex toy, finger or penis. Some people will find cervical stimulation painful or sensitive, while for others it may be pleasurable.

How sex feels can also change depending on your menstrual cycle.

Remember, when you have your period, the cervix is likely to be sitting lower, so this can increase the chance of contact with the cervix during sex, especially during certain sexual positions.

Touching the cervix during sex is very unlikely to cause any damage, although sometimes with vigorous sexual intercourse it can cause bruising. This is not usually dangerous and heals on its own.

Ongoing communication with your partner is crucial to check in and see what feels good for both of you.

So, how long is my vagina?

It can be useful to feel the length of your vagina and the position of your cervix.

For example, if you want to use a menstrual cup during your period, some brands will have different sizes. If you have a shorter vaginal canal, then a shorter or smaller cup may achieve a better fit.

However, other factors – such as your age and how heavy your periods are – can also impact what size is right for you.

To feel the position of your cervix, first wash your hands with soap and water. This is best done around the time of your period, when the vaginal canal will be shorter.

Find a comfortable position, such as sitting, squatting or having one leg bent up on a chair. Then insert your finger into the vagina aiming up and back.

The vagina feels soft and squishy, whereas the cervix is smooth and firm, with a tiny divot in the centre – imagine a mini doughnut.

If you have to really stretch to feel the cervix, you may opt for a longer cup, whereas if you don’t need to insert your whole finger, it is probably sitting a bit lower and you may be more comfortable with a smaller size.

Keep in mind, this will just give you a rough idea of your vagina’s length and where your cervix is sitting (although it may change tomorrow).

Does the length of your vagina matter?

All of our bodies are unique and there is a wide range of “normal”. Generally, having a “short” or “long” vagina doesn’t make any real difference.

For example, a 2009 study of women over the age of 40 found vaginal length doesn’t affect sexual activity or function.

The vagina is extremely elastic and can stretch and mould to accommodate a variety of needs, before returning back to its baseline.

There are some symptoms that would be worth discussing with your GP though, such as pain during sex, difficulty inserting tampons or menstrual cups, or if you are concerned about a prolapse.

Keersten Fitzgerald, Lecturer in General Practice, University of Sydney and Melissa Kang, Professor of Adolescent Health, Co-Head of the General Practice Clinical School, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.