Pregnancy history may be tied to Alzheimer's disease

July 18, 2018, American Academy of Neurology
Credit: CC0 Public Domain

A woman's history of pregnancy may affect her risk of Alzheimer's disease decades later, according to a study published in the July 18, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology. The study found that women who give birth to five or more children may be more likely to develop Alzheimer's disease than women who have fewer births. The study also showed that women who have had an incomplete pregnancy, whether through miscarriage or abortion, are less likely to develop Alzheimer's disease in the future than women who have never had an incomplete pregnancy.

"Estrogen levels double by the eighth week of pregnancy before climbing to up to 40 times the normal peak level," said study author Ki Woong Kim, MD, Ph.D., of Seoul National University in Seoul, South Korea. "If these results are confirmed in other populations, it is possible that these findings could lead to the development of hormone-based preventive strategies for Alzheimer's disease based on the hormonal changes in the first trimester of pregnancy."

For the study, researchers combined the data from two, independent population-based studies from Korea and Greece, with a total of 3,549 women. Women who were currently taking hormone replacement therapy and those who had a hysterectomy or surgery to remove the ovaries were not included in the study.

The women, who were an average age of about 71 at the start of the study, provided information on their reproductive history. They took the diagnostic examination after an average of 46 years from their first childbirth. During that time, the participants took tests of their memory and thinking skills to see whether they had developed Alzheimer's disease or its precursor, . A total of 118 women developed Alzheimer's disease and 896 women developed mild cognitive impairment.

Women who had given birth to five or more were 70 percent more likely to develop Alzheimer's disease than women who gave birth to fewer children. Of the 716 women with five or more children, 59 developed Alzheimer's disease, compared to 53 of the 2,751 women with fewer children. The results stayed the same after researchers adjusted for other factors, such as other medical conditions, use of and breastfeeding.

Women who had experienced an incomplete pregnancy were about half as likely to develop Alzheimer's disease as women who had never had an incomplete pregnancy. Of the 2,375 women who had an incomplete pregnancy, 47 developed Alzheimer's , compared to 71 of the 1,174 women who never had an incomplete pregnancy.

On the tests of memory and thinking skills, women who had five or more children had lower scores than women who had fewer children. On a test where the maximum score is 30 points and scores of 24 or more indicate normal thinking skills and scores of 19 to 23 indicate mild cognitive problems, the women with five or more children had average scores of about 22 points, compared to almost 26 points for the women with fewer than five children.

Women who had one or more incomplete pregnancies had higher test scores than women with no incomplete pregnancies, regardless of how many children they had. For example, among women with five or more children, those with no incomplete pregnancies had average scores of about 22, compared to scores of more than 23 points for those with one or more incomplete pregnancy.

"It's possible that the modestly raised levels of estrogen in the first trimester of are within the optimal range for protecting ," Kim said.

A limitation of the study is that incomplete pregnancies may be been underestimated either because abortions were not reported or because may not have realized that they had miscarriages. Another limitation is that the researchers did not collect information on the timing and cause of incomplete pregnancies.

Explore further: Decrease in mean platelet counts seen during pregnancy

Related Stories

Decrease in mean platelet counts seen during pregnancy

July 8, 2018
(HealthDay)—All women have a decrease in mean platelet counts during pregnancy, according to a study published in the July 5 issue of the New England Journal of Medicine.

Women with high blood pressure during pregnancy more likely to develop CVD risk factors

July 2, 2018
Preeclampsia and gestational hypertension are common pregnancy complications involving high blood pressure that develops for the first time during pregnancy and returns to normal after delivery. Previous studies have shown ...

Thyroid dysfunction may lead to diabetes during pregnancy

June 7, 2018
Women with thyroid dysfunction in the first half of pregnancy face an increased risk for gestational diabetes, a form of diabetes that is typically diagnosed during the second trimester, according to a new study published ...

Does age at menopause affect memory?

April 11, 2018
Entering menopause at a later age may be associated with a small benefit to your memory years later, according to a study published in the April 11, 2018, online issue of Neurology, the medical journal of the American Academy ...

Certain medications for chronic inflammatory diseases appear safe during pregnancy

April 5, 2018
Anti-tumor necrosis factor medications (anti-TNFs) are effective in controlling chronic inflammatory diseases, but some physicians recommend that their patients discontinue them during pregnancy. In an Arthritis & Rheumatology ...

Hypertension during pregnancy may affect women's long-term cardiovascular health

August 18, 2017
Women who experience hypertension during pregnancy face an increased risk of heart disease and hypertension later in life, according to a new study.

Recommended for you

Immune cell pruning of dopamine receptors may modulate behavioral changes in adolescence

September 25, 2018
A study by MassGeneral Hospital for Children (MGHfC) researchers finds that the immune cells of the brain called microglia play a crucial role in brain development during adolescence, but that role is different in males and ...

Scientists reverse a sensory impairment in mice with autism

September 25, 2018
Using a genetic technique that allows certain neurons in the brain to be switched on or off, UCLA scientists reversed a sensory impairment in mice with symptoms of autism, enabling them to learn a sensory task as quickly ...

Why it doesn't get dark when you blink

September 25, 2018
People blink every five seconds. During this brief moment, no light falls on the retina, yet people continue to observe a stable picture of the environment with no intervals of darkness. Caspar Schwiedrzik and Sandrin Sudmann, ...

Researchers identify new cause of brain bleeds

September 25, 2018
A team of researchers including UCI project scientist Rachita Sumbria, Ph.D. and UCI neurologist Mark J. Fisher, MD have provided, for the first time, evidence that blood deposits in the brain may not require a blood vessel ...

Lung inflammation from childhood asthma linked with later anxiety

September 25, 2018
Persistent lung inflammation may be one possible explanation for why having asthma during childhood increases your risk for developing anxiety later in life, according to Penn State researchers.

Exercise may delay cognitive decline in people with rare Alzheimer's disease

September 25, 2018
For individuals carrying a genetic mutation that causes Alzheimer's disease, engaging in at least 2.5 hours of physical activity per week may have beneficial effects on markers of Alzheimer's disease brain changes and may ...

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.