To test two hypotheses: In spontaneous conceptions, early pregnancy loss (EPL) is associated with  inadequate luteal (ovarian) P, and/or  elevated follicular (adrenal) P.
A population-based prospective study.
Thirty rural Bolivian communities.
Women volunteers (n = 191), 19-40 years old, in stable sexual unions and not using contraception.
Collection of serial saliva samples throughout sequential ovarian cycles and urine samples during late luteal phases. Collections continued throughout pregnancy for each detected conception.
Main Outcome Measure(s)
Occurrence of spontaneous conceptions and subsequent outcomes. Salivary concentrations of P. Test for elevated urinary human chorionic gonadotropin (hCG).
Luteal (through implantation) P levels were similar in pregnancies lost within 5 weeks after conception (EPL; n = 8) and those pregnancies that were maintained longer (sustained conceptions, SC; n = 32). Follicular P was significantly higher in EPL than in SC.