11 12 13 14 15 The graph shows the changing levels of hormones during menstruation and ovulation. Which hormone has the most influence on preparing the body for pregnancy? A graph shows the changing levels of hormones during menstruation and ovulation. Progesterone increases after ovulation. Luteinizing hormone promotes fertility because it spikes the most during ovulation. Estradiol promotes fertility because it peaks slightly before ovulation. Progesterone promotes fertility because its levels rise during ovulation and immediately after. Follicle-stimulating hormone promotes fertility because it is released mostly during ovulation.