Relation between maternal weight and serum alpha-fetoprotein concentration during the second trimester

Area of Science:

• Biochemistry
• Obstetrics
• Maternal-Fetal Medicine

Background:

• Maternal serum alpha-fetoprotein (MSAFP) is a key marker in prenatal screening.
• Current reference intervals for MSAFP do not typically account for maternal body weight.
• Variations in MSAFP can be associated with fetal developmental abnormalities and adverse pregnancy outcomes.

Purpose of the Study:

• To investigate the relationship between maternal weight and second-trimester serum alpha-fetoprotein concentrations.
• To determine if maternal weight influences MSAFP levels, potentially impacting their interpretation.
• To explore the clinical utility of adjusting MSAFP reference intervals based on maternal body weight.

Main Methods:

• Analysis of maternal serum samples collected during the second trimester.
• Correlation of alpha-fetoprotein concentrations with maternal weight data.
• Statistical evaluation to identify significant associations and trends.

Main Results:

• A significant inverse correlation was observed between maternal weight and median serum alpha-fetoprotein concentrations.
• Heavier women exhibited lower median MSAFP values compared to women of lower weight.
• The observed dilution effect is attributed to increased maternal blood volume in heavier individuals.

Conclusions:

• Maternal body weight is a significant confounder for second-trimester serum alpha-fetoprotein levels.
• Adjusting MSAFP reference intervals to incorporate maternal weight may improve the accuracy of prenatal risk assessment.
• This adjustment is particularly relevant for optimizing diagnostic utility in heavier women.