Blood prolactin levels: Influence of age, menstrual cycle and oral contraceptives

Prolactinemia during the Menstrual Cycle

“…The progressive increase of prolactin secre tion, starting from the time of ovulation, is in agreement with previous reports [10,19], and is reflected by the parallel increase of progesterone. Thus, the highest plateau lev els of both hormones are obtained imme diately before shedding.…”

“…Serum was stored at -2 0 °C until the time of assay, which was performed on the same occasion for all scrum samples from each single patient. The serum concen trations of FSH, LH, estradiol, progesterone and pro lactin were measured by established R1A procedures [10,11]. Each assay was performed in duplicate, and the intra-and interassay coefficients of variation were < 10% and < 15%, respectively.…”

Effect of Oral Contraceptives on Serum Prolactin: A Longitudinal Study in 126 Normal Premenopausal Women

“…(1984) that the distribution of basal serum prolactin concentrations is skewed to the right at least among normal premenopausal women and that the 'normal' range for this population may need redefinition. On the other hand, when prolactin levels were compared to age-and sex-matched controls, as in the large cross-sectional studies of Davies et al Pansini et al (1983), no significant elevation of serum prolactin among patients taking oral contraceptives could be detected. Some of the apparent discrepancies in earlier studies on the effect of combination-type oral contraceptive agents on serum prolactin concentrations in normal premenopausal women could have been due to a failure to take this factor into consideration.…”

“…Thus, among the larger studies reported recently, Reyniak et al (1980) found that about 30% of 123 subjects on oral contraceptives had 'hyperprolactinaemia', when hyperprolactinaemia was defined as any prolactin concentration above 20 ng/ml, a value presumably derived from the general population. On the other hand, when prolactin levels were compared to age-and sex-matched controls, as in the large cross-sectional studies of Davies et al Pansini et al (1983), no significant elevation of serum prolactin among patients taking oral contraceptives could be detected. Differences in the definition of hyperprolactinaemia, as well as in the oestrogen content of contraceptives employed and perhaps other factors, such as patient selection and time of blood sampling, probably account for the discrepant results among several other earlier studies (Abu-Fadil et al, 1976;Dericks-Tan et al, 1976;Spellacy et al, 1978).…”

“…Results have been more equivocal with combination-type oral contraceptives. Several studies failed to detect any significant effect of oral contraceptives on serum prolactin levels (Spellacy et al, 1978;Pansini et al, 1983;Davis et al, 1984) while others reported definite but modest increases in at least a proportion of the subjects studied (Abu-Fadil et al, 1976;Dericks-Tan et al, 1976;Reyniak et al, 1980). Most of the reported studies carried out in normal premenopausal women involved small numbers of subjects except for three recent crosssectional studies (Reyiak er a!., 1980; Pansini e f a]., 1983; Davis el a]., 1984).…”