Infertility and early pregnancy loss

Area of Science:

• Reproductive endocrinology
• Epidemiology
• Human reproduction

Background:

• Understanding early pregnancy loss is crucial for reproductive health.
• Subclinical pregnancy loss, occurring before clinical detection, impacts fertility outcomes.
• Previous studies have not fully characterized early pregnancy loss in diverse fertility populations.

Purpose of the Study:

• To investigate the epidemiologic characteristics of conception and early pregnancy loss in healthy women volunteers.
• To specifically examine the conception and pregnancy loss experiences of women with documented impaired fertility.
• To identify factors associated with subclinical and clinical pregnancy loss.

Main Methods:

• Prospective observational cohort study of 148 female volunteers from semiconductor manufacturing facilities.
• Daily urine samples collected for 7 months to assay human chorionic gonadotropin (hCG) for conception and ovarian steroid hormones for ovulation.
• Interviews and daily diaries supplemented biological data for comprehensive cycle tracking.

Main Results:

• A total of 679 menstrual cycles at risk for pregnancy were analyzed.
• Women with subfertility exhibited a 70% rate of early pregnancy loss compared to 21% in women without fertility issues (RR 2.6).
• The risk of pregnancy loss associated with subfertility increased with age and was not altered by clomiphene citrate treatment.

Conclusions:

• Subfertile women experience a higher incidence of subclinical pregnancy losses, irrespective of fertility treatments.
• Advancing age may contribute to reduced fertility partly due to an increased rate of early, undetected pregnancy losses.
• These findings highlight the importance of considering subclinical losses in evaluating fertility challenges.