hCG and FSH Levels During Early Pregnancy and Reproductive Aging
Low levels of hCG are known to be co-produced with FSH during reproductive aging (during peri-menopause and menopause). A missed period could be indicative of pregnancy or peri-menopause for woman in later reproductive life, so understanding the reference ranges for hCG is important.
Introduction
- hCG assays have high sensitivity and specificity for pregnancy1
- Low levels of hCG are known to be co-produced with FSH during reproductive aging (during peri-menopause and menopause)2
- Age of motherhood is increasing; 126,956 women over 40 gave birth in 2018*
- Average age of menopause is 51, with most women experiencing menopause between 40 and 58, however, the peri-menopause starts several years before
- Therefore, a missed period could be indicative of pregnancy or peri-menopause for woman in later reproductive life, so understanding the reference ranges for hCG is important
Methods
Not Pregnant Cohort
Samples (first morning void) were collected from not-pregnant women aged 20-65
Pregnant Cohort
Women were recruited preconception to collect daily urine samples (first morning void) from menses to 30 days after conception (if they became pregnant). Day of LH surge was determined for each conception cycle in order to assign day of ovulation (Day following LH surge).
Analysis
hCG, FSH and LH were measured by AutoDELFIA*. A total of 6475 pregnancy samples and 395 non pregnancy samples were examined to create reference ranges.