Antenatal biochemical screening to predict low birthweight infants

Area of Science:

• Obstetrics and Gynecology
• Biochemical Markers in Pregnancy
• Maternal-Fetal Medicine

Background:

• Accurate prediction of low birthweight outcomes is crucial for effective prenatal care.
• Various biochemical markers in maternal samples have been investigated for their predictive potential.
• Identifying high-risk pregnancies aids in targeted fetal monitoring and intervention.

Purpose of the Study:

• To assess the predictive accuracy of several biochemical tests for identifying pregnancies with low birthweight outcomes.
• To determine the optimal use of biochemical screening and centile cut-offs for risk stratification.
• To evaluate the benefit of combining multiple biochemical tests for improved prediction.

Main Methods:

• Measurement of urine and plasma oestriol, plasma progesterone, human placental lactogen, beta 1-glycoprotein, and serum cystyl aminopeptidase in 608 pregnancies.
• Analysis of predictive accuracy of low test values at various gestational ages.
• Calculation of 10th-90th centile values for each test from 28 weeks to delivery.

Main Results:

• No single biochemical test demonstrated superiority across all centiles and gestations for predicting low birthweight.
• Lower centile cut-offs identified higher proportions of low birthweight infants, but in smaller absolute numbers.
• Combining tests below the 10th centile did not significantly improve prediction accuracy compared to single-test centile adjustments.

Conclusions:

• Biochemical screening for high-risk pregnancies has limited potential for identifying low birthweight outcomes.
• Practical clinical criteria may be more effective than statistical cut-offs for defining high-risk groups.
• The utility of higher centile cut-offs for screening depends on the availability and patient acceptance of fetal monitoring facilities.