Older wombs linked to complications in pregnant mice

September 5, 2017
A fluorescent microscopy image of the womb of an elderly mouse. The areas in green show cells which respond to pregnancy hormones. As a mouse ages, the womb becomes less sensitive to hormones, as shown by the uneven, patchy areas of green. This is reflected in the developmental problems we see in the offspring from these older mothers. Credit: Ms. Laura Woods

Deciding to start a family later in life could be about more than just the age of your eggs. A new study in mice suggests the age of a mother's womb may also have a part to play. This work, led by Dr Myriam Hemberger at the Babraham Institute and the Centre for Trophoblast Research in Cambridge, UK, is one of the first to look at the effects of age on womb health and it is expected to lead to new research into human pregnancies.

The risks of complications during all increase with age. A woman in her late 30s is twice as likely as a younger woman to have a stillbirth, she is also 20% more prone to giving birth prematurely and more likely to experience conditions such as pre-eclampsia. Many of these effects have been linked to the deteriorating quality of ageing egg cells. Yet, this new research, published in Nature Communications, reveals that older wombs also have more trouble adapting to pregnancy.

By examining first pregnancies in aged , the team showed that, for mice as for humans, the risk of complications increases with age. Closer examination revealed that the wombs of are less able to support the growth of a placenta, meaning the developing young have poor blood supply, which slows their growth and can cause birth defects.

The co-first authors were Ms Laura Woods and Dr Vicente Perez-Garcia. Speaking about the findings, Ms Woods said: "We wanted to enhance our understanding of the increased risks of pregnancy in older mothers. When we compared mice who have their first litter in middle age to their younger counterparts, we found that the lining of the uterus does not respond as well to pregnancy hormones and this delays placenta formation. By identifying the key pathways affected by age in mice we have a better idea of what to look for in humans."

Understanding the potential risks of pregnancy with age is an increasingly important issue. In the UK, more and more women are starting families later and in 2015, 53% of UK births were to women aged 30 or over. A 2016 report by the Human Fertilisation and Embryology Authority showed that freezing eggs for later use is also growing in popularity. In 2001, just 29 women opted for the treatment, rising to 816 by 2014.

Lead author, Dr Hemberger, Group Leader in Epigenetics at the Babraham Institute, said: "Overall, our study highlights the importance of the ageing uterine environment as a cause of reproductive decline in . This is one of the first times that the considerable impact of age on pregnancy has been studied in detail beyond the effects of egg fitness. More research will be needed to establish if and how our results translate to humans."

The shorter lifespan of mice means that they are useful for studying the effects of age on pregnancy but these results cannot always be directly applied to human pregnancies. These new results will help to guide long-term studies in humans but it is not yet clear what the implications of these findings will mean for family planning and human healthcare. It is clear that other factors besides egg quality may need to be considered when planning a family.

As a member of the Royal College of Obstetricians and Gynaecologists, Ashley Moffett, Professor of Reproductive Immunology at the University of Cambridge and expert on placenta formation, said: "We know that the so-called Great Obstetrical Syndromes, in particular pre-eclampsia are more common in older women but it's still not clear why. Although more work is needed to demonstrate this effect in humans, this study could help advance research into these important questions".

Explore further: Weight gain between pregnancies linked to increased risk of gestational diabetes

More information: Laura Woods et al, Decidualisation and placentation defects are a major cause of age-related reproductive decline, Nature Communications (2017). DOI: 10.1038/s41467-017-00308-x

Related Stories

Weight gain between pregnancies linked to increased risk of gestational diabetes

August 1, 2017
The risk of developing gestational diabetes mellitus (GDM) increases with increased weight gain between pregnancies, according to a new study published in PLOS Medicine by Linn Sorbye of the University of Bergen, Norway, ...

Mothers with pre-eclampsia may encounter challenges later in life

August 25, 2017
A new study has found that a condition that threatens the lives of some pregnant women and the fetus may continue to put the mother at risk later in life.

Being South Asian is as great a risk factor for stillbirth as smoking

June 29, 2017
Australian women born in South Asia are more likely to have a stillbirth than other women, perhaps due to a rapidly ageing placenta that cannot support the pregnancy, new research suggests.

Women's wellness: pregnant later in life

January 10, 2017
Are you considering pregnancy after 35? Understand the issues for older mothers - and know what it takes to have a healthy pregnancy.

White blood cell treatment could prevent leading cause of fetal death

December 12, 2016
Treating a type of white blood cell using hormones could improve the development of the placenta in women with pregnancy complications, according to early research led by Queen Mary University of London (QMUL) involving mice ...

Recommended for you

Sleeping position linked to the risk of stillbirth

November 20, 2017
Pregnant women who go to sleep on their back during the later stages of pregnancy face an increased likelihood of suffering a stillbirth, according to new research.

Study in mice finds dietary levels of genistein may adversely affect female fertility

November 14, 2017
Exposure to the phytoestrogen genistein prior to conception may adversely affect female fertility and pregnancy outcomes, depending on the dosage and duration of exposure, a new study in mice suggests.

IUDs may have a surprising benefit: Protection against cervical cancer

November 7, 2017
Considered a safe and highly effective contraception method, intrauterine devices (IUDs) may also be quietly offering protection against the third-most common cancer in women worldwide. A new study from the Keck School of ...

Increasing rates of chronic conditions putting more moms, babies at risk

November 7, 2017
Pregnant women today are more likely to have chronic conditions that could cause life-threatening complications than at any other time in the past decade - particularly poor women and those living in rural communities, a ...

First time mums with an epidural who lie down more likely to have a normal birth

October 18, 2017
Adopting a lying down position rather than being upright in the later stages of labour for first-time mothers who have had a low dose epidural leads to a higher chance of them delivering their baby without any medical intervention, ...

Mice delivered by C-section gain more weight than those delivered naturally

October 11, 2017
Mice born by Caesarian section gained on average 33 percent more weight in the 15 weeks after weaning than mice born vaginally, with females gaining 70 percent more weight.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.