People whose mothers had them after age 35 may be more likely to have heart problems, new research suggests.
University of Alberta researchers studied female rats that give birth to offspring with impaired blood vessels and greater risk of heart problems as adults, the University of Alberta study found.
As more women focus on their careers earlier in life and reproductive medicine advances, the number of babies born to women over 35 is surging.
The children of women who undergo IVF or use frozen or donor eggs are still at risk of cardiovascular problems, as both the age of the egg and the placenta play a role in the development of the fetus’s system of blood vessels.
‘This research is important because it improves our understanding of the impact of giving birth at an older age on the health of offspring in later life,’ said lead study author and executive director of the Women and Children’s Health Research Institute, Dr Sandra Davidge.
Children whose mothers gave birth to them after the age of 35 are at higher risks of cardiovascular issues later in life, a new study of
But, she says, these greater risks should not scare older women away from having children, just be used to help them better prepare for pregnancy.
Having a baby at an older age has long been known to come with unique risks., Women who become pregnant over 35 are more likely to have children with growth difficulties and chromosomal abnormalities, such as Down’s syndrome.
They are also more likely to develop high blood pressure or a form of pregnancy-related diabetes and at higher risk of losing the pregnancy or delivering prematurely.
Women are born with a set number of eggs, one of which is released each month during ovulation.
As they age, both the number and quality of these eggs starts to decline, a process that accelerates more rapidly after the age of 35.
Plus, women themselves (and men, for that matter) are at greater risks of chronic health conditions and the general degeneration of their bodies as they get older.
‘Pregnancy is a fascinating event – especially its effects on our cardiovascular system,’ says Dr Davidge.
The volume of blood in a woman’s body increases steadily over the course of her pregnancy, and her heart gets bigger and pumps harder in order to distribute that blood – enriched with additional immune cells – throughout her body and to the fetus growing in her belly.
Despite all of these incredible changes, a woman’s blood pressure does not change in a complication-free pregnancy.
But these physiological shifts put more strain on the bodies of older women, making them more vulnerable to preeclampsia, or pregnancy-related high blood pressure.
The exact causes of preeclampsia are unclear, but are likely related to the way that blood vessles form in the placenta.
Blood vessels supplying the placenta are more narrow than those in the rest of a woman’s body, which may cause the pressure in her overall system to build up.
Plus, older women’s placentas may not have as robust a development, limiting its ‘capacity for nutrient exchange’ and, in turn, potentially impairing fetal development, says Dr Davidge.
Together, these factors, ‘in the whole concept of how a developing fetus is susceptible to chronic diseases later in life has a lot to do with epigenetic mechanisms: how the environment can change the the genes, leading to changes in proteins and to changes in some aspects of cardiovascular development,’ she explains.
The children of older women who used IVF, frozen eggs or donor eggs are not out of the woods either. ‘It’s not just an older egg, it is also about the uterine receptivity – like soil and seed – it takes two to tango,’ she says.
Both male and female offspring born to older rats showed signs of weaker cardiovascular systems, though the males seemed much more affected at just a few months old.
This was unsurprising to Dr Davidge. Regardless of maternal age, male and female offsprings’ placentas develop differently and, early on, ‘males tend to be more susceptible [to cardiovascular problems], but females catch up,’ she says.
Those born to older mothers would be less resilient to epigenetic, environmental factors – like diet and exercise habits – that might make increase their cardiovascular risks, meaning that forming these good lifestyle practices early in life may be particularly important to them.
‘Some sets of the population are more susceptible to secondary hits, and therefore it is even more necessary to start good habits earlier,’ says Dr Davidge.
Her research needs to be tested in humans, but suggests that older women who want to conceive should ‘go into pregnancy the best fit that you can be. Just being healthy, having good nutrition, being in a good physical state is critical for everybody at all ages.’
‘None of these prenatal exposures [should be cause] to blame the mother, but we all have risk factors and knowledge and awareness of them is important,’ Dr Davidge says.