Size and shape of the pituitary gland during pregnancy and post partum: measurement with MR imaging.

Abstract

Cranial magnetic resonance (MR) imaging was performed in 38 pregnant and postpartum women and 30 nonpregnant age-matched control subjects to establish standards for pituitary gland size and shape during this period. Gland height and infundibulum width were measured on midline T1-weighted sagittal images. Gland convexity or concavity was graded qualitatively. Throughout pregnancy, gland height increased linearly by approximately 0.08 mm/wk. No gland exceeded 10 mm in height during pregnancy. Increases in gland convexity also correlated with progression of pregnancy. The largest glands were seen in the immediate postpartum period; during this period, five of 12 glands measured 10.0-11.8 mm. Beyond the first week post partum, glands rapidly returned to normal size, apparently regardless of the status of breast-feeding. The mean diameter of the infundibulum was 2.2 mm (range, 0.8-4.0 mm). The pituitary gland enlarges throughout pregnancy but should probably not exceed 10 mm during most of this period. Size of up to 12 mm may be acceptable immediately post partum.

Pituitary volume and the effects of phototherapy in patients with seasonal winter depression: a controlled study

“…24,25 Women tend to have larger glands than men, with additional transient increases during pregnancy and early postpartum period. [26][27][28] The results of the present study show no group mean differences in the pituitary volume between patients with SAD and healthy volunteers in winter or summer. These findings are in agreement with those reported by Schwartz et al, 17 describing similar results of pituitary size in patients with SAD.…”

The expansion of adult stem/progenitor cells and their marker expression fluctuations are linked with pituitary plastic adaptation during gestation and lactancy

“…A mitotic variability was described in the anterior pituitary of female rats (38,56) in the estrous cycle and also during pregnancy and lactation (5,13,14), with estrogen being the principal cause for the increased lactotroph cell population (31). Considering the evidence of an SC/P niche in the adult pituitary and in an attempt to achieve a better understanding of the new endocrine cell supply during the cell turnover that occurs in states such as reproduction, we evaluated in vivo the SC/P contribution to the cell differentiation during gestation and lactancy.…”

ENDOCRINOLOGY IN PREGNANCY: Management of the pregnant patient with a prolactinoma

“…This rise in PRL level is thought to prepare the breast for lactation. Magnetic resonance imaging (MRI) scans show a gradual increase in pituitary volume over the course of gestation, beginning by the second month and peaking the first week postpartum with a final height reaching to almost 12 mm (44,45).…”