- Women having unhealthy blood fat levels such as increased LDL cholesterol and triglycerides may have impaired (weakened) fertility and have only one child or no children at all
- Previous studies have found that women who suffered heart disease and stroke had no children or one child only
- It is unclear whether reduced female fertility and heart disease share common biological factors that might account for higher incidence of heart disease and stroke in childless or one-time mothers
Women who have unhealthy lipid or fat levels in their blood before pregnancy may be at increased risk of reduced fertility and may have only one child or no children at all, according to an observational study by Norwegian scientists which appears in the online journal BMJ Open.
Details of Study
In order to determine whether reduced fertility and heart disease in women had some common biological factors, the study team analyzed the possible influence of high cholesterol, triglycerides, and the ratio between the two types of blood fats before pregnancy on the number of children born soon after.
They team gathered information from the national birth (MBRN) and health (CONOR) data, including blood samples taken from women aged 20 years and above staying in different parts of Norway between 1994 and 2003, as well as lifestyle and dietary data.
‘Metabolic abnormalities such as dyslipidemias leading to unhealthy lipid (fat) profiles are an independent risk factor for fertility issues even in women of normal weight.’
The final analysis of the study included 4322 women - 1677 women who were childless; 488 one-time mums; and 2157 women with two or more children. One-time mums referred to women who had had no more pregnancies from six years after their first pregnancy
Findings of Study
The key findings of the study were the following -
- Occurrence of known risk factors of heart disease was found to be more in childless women and one-time mums; they were more likely to be older (34+ years), overweight/obese (higher BMI), and more likely to be smokers than women who had had two or more children.
- One-time mothers had lesser years of education and higher incidence of diabetes
- Also women with only one child were twice as likely to have had fertility treatments
- Women with an 'unhealthy' blood fat profile, (namely high levels of LDL ('bad') cholesterol, triglycerides, and a high triglyceride to HDL ('good') ratio, as well as low levels of HDL cholesterol), that was estimated many years before they became pregnant, were 20 to 100 percent more likely to have had only one pregnancy
- Elevated LDL and total cholesterol concentrations were also associated with increased chances of having no children, similar to being overweight or obese
- Compared to women who had had two or more pregnancies, total cholesterol levels above the normal range was associated with an increased risk of remaining childless, irrespective of body mass index (BMI).
Possible Demerits of Study
Since this was an observational study,
it cannot establish cause. Also blood samples were not taken after a period of fasting
, and there was no data on chemical markers
that might affect women's fertility
, all of which could have possibly influenced the findings.
Nevertheless, the findings of the current study echo earlier studies, which found that metabolic abnormalities among women who were normal weight were an independent risk factor for having fertility problems.
The authors therefore conclude that, "Pre-existing poor lipid and metabolic profiles could represent one of the possible linkages between previously observed fertility and later [cardiovascular disease]."
What Women with Fertility Issues Can Do to Reduce Heart Disease Risk Later
Some men and women are genetically pre-disposed to develop certain diseases, but it is possible to reduce heart disease risk by making better lifestyle choices. Adopting a heart healthy lifestyle can help reduce the chances of developing heart disease later. Some of the simple measures include -
- Adopting a healthy diet rich in fresh fruits and vegetables
- Avoidance of fast foods rich in saturated fats
- Stop smoking and reduce alcohol intake
- Regular exercise
- Stress management techniques such as meditation and relaxation
- Good restful sleep
These simple measures could reduce risk of heart disease, improve chances of pregnancy and can enhance overall physical and emotional well-being.