Pregnancy causes many hormonal changes, with some research suggesting it may even impact some of the brain’s functions. A new study suggests there may be cognitive advantages to having a pregnancy later in life,MNT reports.
Some studies have linked higher levels of estradiol and cortisol with lower attention and have suggested mothers may have poorer verbal memory during pregnancy.
Negative emotional states have also been reported during pregnancy. In fact, 1 in 9 women experience depression before, during, or after pregnancy, according to the Centers for Disease Control and Prevention (CDC).
However, in the long run, pregnancy hormones may lead to better cognition and memory. A new study investigates the link between age at last pregnancy and a mother’s cognitive abilities later in life.
Assessing the link between reproductive history and cognition
Researchers at the University of Southern California examined the association between reproductive history, hormonal exposure, and cognition in postmenopausal women.
Factors that influence hormonal exposure and that were considered by the study included reproductive period, pregnancy, and use of hormonal contraceptives. The analysis evaluated a total of 830 women, using data from two clinical trials.
The average age of the participants was 60 years. The researchers made the necessary adjustments for age, race and ethnicity, income, and education.
Participants were evaluated using a variety of cognitive tests and a reproductive history questionnaire. Researchers tested participants’ verbal memory by asking them to remember a list of words or to retell a story after being distracted.
They also assessed their psychomotor speed, attention span, and concentration, as well as their planning abilities, visual perception, and episodic memory.
The findings have been published in the Journal of the American Geriatrics Society.
Pregnancy after 35 linked to better cognition
The study revealed several associations, some of which have been supported by previous research, while others were more surprising.
The study found that postmenopausal women who had their last pregnancy after the age of 35 had better verbal memory.
Those who had their first pregnancy when they were 24 or older had significantly better executive function. This includes attention control, working memory, reasoning, and problem solving.
The study also revealed that having the first menstrual cycle at an early age, along with a longer reproductive life, also led to better executive function in later life.
Estrogen has been shown in previous studies to impact positively on the brain’s chemistry, function, and structure in animal studies, explains lead author Roksana Karim, assistant professor of clinical preventive medicine at University of Southern California’s Keck School of Medicine. Progesterone has been associated with brain growth and development of brain tissue, she adds.
Researchers also found that women who had used contraceptives for 10 years or more had better verbal memory and critical thinking skills. “Oral contraceptives maintain and sustain a stable level of sex hormones in our bloodstream,” Karim says. “Stable is good.”
One result that surprised the researchers was the positive effect an incomplete pregnancy seemed to have on cognitive function.
Women who did not carry their pregnancy to term had better cognition, verbal memory, and executive function, compared with women who had only one full-term pregnancy.
“The finding that even incomplete pregnancies are beneficial was novel and surprising,” says senior author Wendy Mack, professor of preventive medicine at the Keck School of Medicine.
Parity was also found to associate positively with cognition. Women who gave birth to two children had better cognition in older age, compared with mothers of one child.