Two new studies published this week has found that women who wait until later in life to start or finish their family benefit from various health improvements.

In the first study to investigate the association between age at last pregnancy and cognitive function in later life, a team of researchers from Keck School of Medicine of USC, California, USA, found that women who have their last baby later in life can benefit from improved brainpower after menopause.

Published this month in the Journal of the American Geriatrics Society, the research looked at 830 women with an average age of 60.

Participants were asked to complete a series of tests to assess cognitive function.

After taking into account various factors such as age, race and ethnicity, income, and education, the team found that women who had their last pregnancy after 35 had better verbal memory than those who had had finished their family earlier.

Those who had their first pregnancy when they were 24 or older also had significantly better executive function, which is responsible for attention control, working memory, reasoning and problem solving, and women who didn't carry their pregnancy to term or who gave birth to two children also had better overall cognitive ability, verbal memory and executive function than woman who had had only one full-term pregnancy.

In addition those who began their menstrual cycle before age 13, or had a longer reproductive life with more time between their first and last period, also benefited from improved executive function.

Using the pill or other hormonal contraceptives for at least 10 years was also beneficial for verbal memory and critical thinking ability.

However lead author Roksana Karim also pointed out that, "Based on the findings, we would certainly not recommend that women wait until they're 35 to close their family, but the study provides strong evidence that there is a positive association between later age at last pregnancy and late-life cognition."

In another study out this week, published online in the American Journal of Public Health, a team from University of California San Diego School of Medicine found that women who start their family later in life may be more likely to live into their 90s.

The study, which is the first to look at an association between the age a woman has her first child and longevity, looked at around 20,000 participants who were followed for up to 21 years.

The researchers found women who had their first child at age 25 or older or who had had two to four term pregnancies were more likely to live to age 90.

Women who were college graduates, married, had a higher income, were not obese and did not have a history of chronic disease were also more likely to live longer.