Temporal refinement does not affect predicted human chorionic gonadotropin rise in early pregnancy

Area of Science:

• Reproductive Endocrinology
• Clinical Chemistry
• Obstetrics and Gynecology

Background:

• Accurate assessment of human chorionic gonadotropin (hCG) rise is crucial for early pregnancy monitoring.
• Variations in laboratory testing and infrequent measurements can impact the precision of hCG level estimations.
• Existing models for hCG rise may not fully account for temporal imprecision in clinical data.

Purpose of the Study:

• To evaluate the effect of data validation and temporal resolution on the estimation of hCG increase.
• To determine if improved temporal precision alters the interpretation of hCG trends in early pregnancy.
• To assess the validity of current hCG rise models in diagnosing nonviable gestations.

Main Methods:

• Retrospective cohort study of women with symptomatic first-trimester pregnancies.
• Analysis of serial human chorionic gonadotropin (hCG) level measurements over time.
• Data verification and improved temporal precision applied to hCG measurements.

Main Results:

• 118 subjects with 327 hCG values met inclusion criteria after data verification.
• Improved temporal precision revealed a steeper hCG rise compared to raw clinical data.
• The predicted 2-day hCG increase at the 1st percentile was faster with precise data (1.68-fold vs. 1.56-fold).

Conclusions:

• Data verification and enhanced temporal precision suggest a faster hCG increase in early intrauterine gestation.
• Current modeling of expected hCG rise is valid and appropriately conservative for diagnosing nonviable gestations.
• No changes are recommended for the minimal threshold for potential viability based on these findings.