Urinary excretion of oestrogens during pregnancy, lactation, and the re-establishment of menstruation.

Abstract

A new chemical method for estimating the urinary excretion of estriol estrone and estradiol 17beta during conception pregnancy puerperium lactation and resumption of menstruation postpartum is described and used to measure these levels in women; the results of 4 are presented here. 2 subjects were studied for levels of urinary estrogens over a period which included a complete menstrual cycle and the cycle in which pregnancy started. In both women the urinary estrogen levels were similar in the 2 cycles up to about Day 24 showing ovulation peaks and subsequent luteal rise. In the first cycle estrogen levels then decreased before onset of menstruation but in the second pregnancy cycle estrogen concentrations continued to increase increasing rapidly about 7 weeks after the last menstrual period. In all 4 subjects (results are presented both in a logarithmic scale and in tabular form) there was a rapid rise in urinary levels of the 3 estrogens throughout pregnancy which was greatest from Weeks 6-12. The estrone and estradiol levels at labor were 100 times higher than those during the luteal phase of the menstrual cycle with the estradiol levels being about one-third of the estrone levels. The urinary estriol levels rose about 1000-fold during this time. 1 subject followed after delivery showed that during the first menstrual periods after delivery ovulation did take place but the luteal phases were abnormally short.