Having your first baby between ages 25-35 is tied to being healthier at 40...

It is a fact of life, that as a woman ages, so her fertility decreases.

Yet, the pressures of modern life dictate that more and more women are delaying motherhood, instead focusing on their careers and financial pressures.

The decision can be a difficult one, but now a new study has offered older women a ray of hope.

Those who delay motherhood until their late 20s and early 30s, are more likely to enjoy better health when they reach 40 years old.

Conversely, women who give birth to their first child between the ages of 15 and 24 have worse health in midlife.

Furthermore, teenage mothers had ‘no significant health differences’ in midlife from women who gave birth for the first time in their early 20s.

The study is the first in the US to find that having your first child in young adulthood is associated with worse self-assessed health decades later. 

Currently, close to one-third of all US first births occur in women between the ages of 20 to 24, according to a recent National Vital Statistics Report.

Dr Kristi Williams, study co-author and an associate professor of sociology said: ‘We still need to be concerned that women who are having births in their early 20s may face more health challenges as they reach middle age than those who wait longer.’ 

The study analyzed data from 3,348 women who participated in the National Longitudinal Survey of Youth 1979.

The NLSY79 is conducted by Ohio State's Center for Human Resource Research for the U.S. Bureau of Labor Statistics. 

Each of the women investigated in the study gave birth between the ages of 15 and 35.

They were interviewed every one or two years from 1979 through 2008.

The women rated their own health at age 40 on a scale from poor to excellent.

Researchers compared women who had their first birth as teenagers (ages 15-19), during early adulthood (20-24) and when they were older (ages 25-35).

Women who were between the ages of 25 and 35 tended to report having better health at age 40 than the other two groups.

Yet, women who gave birth for the first time as teenagers and young adults reported similar states of health at midlife.

Dr Williams said: ‘We’ve had all this focus on the bad effects of teen childbearing but never really asked what happens if these teens waited until early adulthood.

‘The assumption has been that “of course, it is better to wait".

‘But at least when it comes to the later health of the mother, that isn’t necessarily true.’

The study also found that women who were married when they had their first child reported better health at age 40.

And yet, for black single mothers, those who never married after giving birth had better self-reported health than those who did marry. 

Researchers aren’t sure why the health of black single mothers varies so heavily.

However, studies suggest that many black single mothers ‘face a lack of eligible men who have good economic prospects’.

Those who do marry are likely to have a spouse who didn’t have a good education or job, the study said.

Researchers compared women who had their first birth as teenagers (ages 15-19), during early adulthood (20-24) and when they were older (ages 25-35).

Women who were between the ages of 25 and 35 tended to report having better health at age 40 than the other two groups.

Yet, women who gave birth for the first time as teenagers and young adults reported similar states of health at midlife.

Dr Williams said: ‘We’ve had all this focus on the bad effects of teen childbearing but never really asked what happens if these teens waited until early adulthood.

‘The assumption has been that “of course, it is better to wait".

‘But at least when it comes to the later health of the mother, that isn’t necessarily true.’

The study also found that women who were married when they had their first child reported better health at age 40.

And yet, for black single mothers, those who never married after giving birth had better self-reported health than those who did marry. 

Researchers aren’t sure whey the health of black single mothers varies so heavily.

However, studies suggest that many black single mothers ‘face a lack of eligible men who have good economic prospects’.

Those who do marry are likely to have a spouse who didn’t have a good education or job, the study said.

That could lead to stress and conflict in marriage – and negatively affect the woman’s health.

But the researchers stressed that the study specifically focused on women who were born in the early 1960s – and that some factors have changed for those who grew up later.

The National Vital Statistics Report noted that most women who gave birth between the ages of 20 and 24 were single mothers.

The report also found that the proportion of black women having a teen birth has declined significantly.

But, 63 per cent of all first births to black women still occur among those aged 24 or younger.

The study was co-authored by researchers from Ohio State, Cornell University, the University of Wisconsin-Madison and the University of Akron.

The research was published in the Journal of Health and Social Behavior.

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