A simplified determination of the urinary luteinizing hormone surge using the hemagglutination inhibition test.

The hemagglutination-inhibition test for urinary luteinizing hormone (LH) has been modified so that the test for LH surge can be assayed in 1 day. A first morning voided urine specimen submitted to the laboratory can be analyzed in 5 hours by ordinary bench procedures. This modification involves a 20-fold reduction, as compared with the older procedure, of the duration of incubation of the urine-antiserum mixture. Another modification is the choice of aliquots which are adaptable to automatic pipetting. Only a single dilution of urine is necessary to determine LH surge for the anticipation of ovulation. Daily LH determinations on 12 normally menstruating women (av. cycle 28.18 days) reveal consistent patterns. For the 40 cycles studied LH surge occurred 14.29 days (av.) prior to the onset of the next menstruation and coincided with the rise in basal body temperature. One woman with an unusually high incidence of familial twinning showed two large LH surges in each consecutive cycle.