Long-term plasma lipid changes associated with a first birth: the Coronary Artery Risk Development in Young Adults...

Area of Science:

• Cardiovascular Health
• Reproductive Health
• Lipid Metabolism

Background:

• Previous research indicates a decline in high-density lipoprotein (HDL) cholesterol 1-2 years post-pregnancy.
• Understanding the long-term impact of childbearing on lipid profiles is crucial for cardiovascular risk assessment.

Purpose of the Study:

• To prospectively examine the association between childbearing and changes in fasting plasma lipids (HDL, LDL, total cholesterol, triglycerides) in US women.
• To investigate if these lipid changes differ by race and parity over a 10-year follow-up period.

Main Methods:

• Prospective cohort study (1986-1996) of 1,952 US women (Black and White) from the Coronary Artery Risk Development in Young Adults (CARDIA) study.
• Repeated-measures multiple linear regression analyzed lipid changes over 10 years (baseline to years 5, 7, 10) in groups based on pregnancy/birth history (0, >=1 miscarriage/abortion, 1 birth, >=2 births).
• Analyses were fully adjusted for numerous covariates including race, age, smoking, diet, weight, and physical activity.

Main Results:

• A first birth was significantly associated with a decline of -3 to -4 mg/dl in HDL cholesterol for both races compared to women with no pregnancies (p < 0.001).
• Higher-order births did not show a greater decline in HDL cholesterol compared to a first birth.
• In White women, declines in total and low-density lipoprotein (LDL) cholesterol were also associated with follow-up births.
• The observed HDL cholesterol decline after a first birth persisted for 10 years, irrespective of weight changes, central adiposity, or lifestyle modifications.

Conclusions:

• Childbearing, particularly a first birth, is associated with a sustained decrease in HDL cholesterol levels in US women.
• These lipid changes occur independently of major weight and lifestyle factors, suggesting a direct biological link between pregnancy and altered lipid metabolism.
• Further research may be warranted to explore the mechanisms underlying these persistent HDL cholesterol reductions and their long-term cardiovascular implications.