Pregnancy and mortality

Mamas on Bedrest: Does Pregnancy Protect Against Cardiovascular Disease?

April 6th, 2012

My grandmother, Holly Alston Turner had 13 pregnancies and 15 children. Yes, you read correctly, 15 children! Born in 1897, she had my Aunt Candace, her first born in approximately 1917 and my dad, her youngest in 1940. In between she had a child about every 18 months to 2 years. She had 2 sets of twins, boys born after Aunt Candace and girls who are 4 years older than my dad. Unfortunately the boys died of childhood illnesses before the age of 3. My grandmother died in the summer of 1967 just before her 70th birthday in December from a stroke.

When I saw the article title from Medscape, “More Pregnancies, Longer Life? I immediately thought of my grandmother. In this study, researchers sought to determine the association between reproductive history and all causes of cardiovascular (heart disease and stroke) death. This is what they found:

“This study searched for an association between gravidity/parity and overall mortality from cardiovascular disease (CVD), including coronary heart disease (CHD) and non-coronary heart CVD, in 1294 middle-class women (the Rancho Bernardo cohort). Clinic visits, questionnaires, physical examinations, and laboratory testing were used for data collection. Gravidity/parity was used to divide the cohort into 5 groups (0, 1, 2, 3, 4 or more). The average age of the participants was 70.6 years; both the median gravidity (number of pregnancies) and the median parity (number of live births) were 2. The average age at menopause was 46.5 years, and the average duration of menopause was 23.7 years. During follow-up, 707 of the 1294 women died, with 46.5% of the deaths attributed to CVD (20.5% to CHD and 26% to non-CHD CVD).

Women with higher gravidity/parity were older at menopause, spent fewer years in menopause, had slightly higher body mass index, were less likely to be current users of estrogen therapy, and were more likely to be receiving diabetes medication.

Multivariate analysis controlling for age and other known risk factors found that women with 4 or more pregnancies had lower risks for overall CVD mortality (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.38-0.96) and non-CHD CVD mortality (HR, 0.48; 95% CI, 0.26-0.90) in comparison with nulligravid women. Trend analysis showed reduced risk for overall CVD mortality and non-CHD CVD mortality with increased gravidity.”

The findings from this study did not match findings from similar studies seeking answers to the same question. While one study reported a slightly increased risk for cardiovascular disease and coronary heart disease among women with 6 or more pregnancies, another found an increased risk for myocardial infarction (heart attack) in women with 5 or more deliveries. This study had different observations. Women with high gravidity (4 or more pregnancies) had lower risk for overall CVD and non-CHD CVD mortality.

But the authors of this study recognize that many factors play into a woman’s mortality. One has to look at ability to conceive-did she have problems and utilize fertility treatments, for example. What is her overall socioeconomic status? Many women of lower socioeconomic means have fewer children. Women who have many pregnancies, especially those without complications may in fact have better overall health to begin with, so would have lived longer and would have been less likely to develop cardiovascular disease anyway. It’s a fascinating subject that will clearly have to be researched further before any definitive answers are obtained.

As for my grandmother, I think many factors contributed to her reasonably “young death”. Raised in the south, she had what many of us would call the “southern palate”, a high fat high salt diet which we know contributes substantially to cardiovascular disease-especially in African Americans. Two months after giving birth to my father, my grandfather died, so she was left to raise the 10 children she had at home on her own. She was definitely of low socioeconomic means which we know contributes to higher rates of morbidity and mortality for all diseases across all ethnicities. She was an African American woman in this country when segregation and racial discrimation was the norm and was not at all challenged. She would be a diffiicult study participant in that there are so many confounding variables in her history it would be hard to know what really caused anything.

And I believe that is the conclusion these researchers came to. It would be nice to say that having several pregnancies is protective to women’s health, but as we see with my grandmother, it clearly had little to no bearing. One could argue that my grandmother had an excessive number of pregnancies that stressed her body and her heart. Possibly. Her southern upbringing and dietary habits certainly didn’t help her health. True. Stress?? We can’t even go there. I think in time we will be better able to assess the effect that pregnancy has on a woman’s overall health long term, but we’ll also have to find a way to factor in a woman’s environment and the role it also plays on her health.