In singleton pregnancies, a first-trimester kisspeptin level of less than 1463 pmol/L had an 80% sensitivity (95% CI 66%–90%) and a 75% specificity (95% CI 72%–78%) for miscarriage, and a kisspeptin level of less than 1630 pmol/L had 86% sensitivity (95% CI 73%–94%) and 70% specificity (95% CI 67%–73%) for detecting miscarriage. The gene discussed is KISS1; the disease is spontaneous abortion.