Female Pituitary Size in Relation to Age and Hormonal Factors

Abstract

Background: It is well known that pituitary volume decreases with age; little is known about the influences of female cycle, intake of oral contraceptives, number of given births and duration of menopause on pituitary morphology. Furthermore, these contexts have never been examined with 3-tesla MRI, from which a high spatial resolution is expected. Methods: Ninety-four women from 18 to 80 years (mean 64 years) had to answer a questionnaire concerning their cycle situation, menopause, hormone intake and childbirths before receiving a 3-tesla MRI scan (Achieva, Philips, N.V.), including a T₁-weighted TSE sequence of the sella turcica. Pituitary volumes and diameters were measured with the software iplan® (BrainLAB, Feldkirchen, Germany). Results: A significant reverse correlation was found between age and pituitary volume (p < 0.0001)/cranio-caudal diameter (p = 0.02). In addition, an age-independent influence of oral contraceptives was found, indicating smaller pituitary sizes with hormone intake (p = 0.003). Cycle phase, number of given births and onset or duration of menopause had no effects on pituitary size. Conclusion: Three-tesla MRI suggests that pituitary volume not only decreases with age, it also seems to be related to long-term hormonal changes such as intake of oral contraceptives.

Estrogen- and progesterone-mediated structural neuroplasticity in women: evidence from neuroimaging

“…No menstrual cycle dependent effects were found on pituitary size (Grams et al 2010). As pituitary size did not change in response to menstrual fluctuations in estrogen, the degree of hormone variation may need to be quite large in order for pituitary size to be affected in a detectable way.…”

“…Additionally, women taking OCPs were found to have slightly smaller pituitary volumes than naturally cycling women (Grams et al 2010). …”

“…Of the 25 papers we identified: 14 papers examined structural brain changes associated with natural menstrual cycling and use of hormonal birth control (Baroncini et al 2010; De Bondt et al 2013a, b; Grant et al 1988; Hagemann et al 2011; Lisofsky et al 2015b; Ossewaarde et al 2013; Pletzer et al 2010, 2015; Protopopescu et al 2008a; Teasdale et al 1988; Tu et al 2010, 2013; Witte et al 2010), seven examined structural brain changes associated with pregnancy and the postpartum period (Dinc et al 1998; Elster et al 1991; Gonzalez et al 1988; Hinshaw et al 1984; Kim et al 2010; Miki et al 2005; Oatridge et al 2002), 3 papers examined structural brain changes associated with the menopause transition (Goto et al 2011a, b; Sullivan et al 2005), and 1 paper examined structural pituitary changes across multiple categories (Grams et al 2010). We identified instances where study subjects were included across two publications: Teasdale et al (1988) and Grant et al (1988), Goto et al (2011a, b), and De Bondt et al (2013a, b).…”

Does the Pituitary Gland Volume Change in Polycystic Ovary Syndrome?

“…Incompatible with our study, these results show us that the pituitary volume is a hormone-dependent quite variable structure. In a study held by Grams et al [14], pituitary volume was found to be lower in patients using combined oral contraceptive pills and pituitary volume changes were emphasizes during the menstrual cycle. We think that decreased pituitary volume was due to suppressed LH and FSH, and according to this hypothesis, in PCOS, increasing LH is responsible for increasing pituitary volume.…”

“…Pituitary gland size increases from 30 to 100% during the third trimester of pregnancy [13]. Also, the pituitary volume is lower in combined oral contraceptive users than in those who are not [14]; therefore, previous studies have demonstrated that the pituitary volume is affected by hormonal changes. Therefore, the aim of the current study is to assess whether pituitary gland volume (PGV) changes in patients with PCOS or not.…”