Timing of ovulation and implantation in the common marmoset, Callithrix jacchus, by monitoring of estrogens and 6 beta-hydroxypregnanolone in urine.

Urinary estrogen and 6 beta-hydroxypregnanolone excretions have been determined in female marmosets by means of HPTLC. The levels observed in cycling females during implantation and abortion are reported. Hormone analysis revealed a characteristic pattern showing cyclic fluctuations of estrogens and progesterone. Estrogen metabolites increase during the follicular phase up to 1 microgram/ml, the progesterone metabolite level rises to 1.2 micrograms/ml urine during the luteal phase. Maximum values of both are superimposed in many cases. Ovulatory cycles can be monitored by following estrogen and progesterone metabolites in urine samples. Thus ovulation and the onset of pregnancy can be estimated with a precision of +/- 24 h (or less).