Objective: To investigate the potential risk for developing visual loss during single or multiple pregnancies in women with pituitary adenomas.
Design: Cohort study.
Setting: Referral center of a neuro-ophthalmology service.
Patients: 65 consecutive women with pituitary adenomas who had not been previously treated with surgery or radiation were monitored during 111 pregnancies. Sixty had increased levels of serum prolactin or growth hormone and 5 did not.
Main outcome measures: Visual field or acuity loss was compared with the baseline size of the adenoma measured on the coronal view of the computed tomographic or magnetic resonance image.
Results: Computed tomography or magnetic resonance imaging showed a definitive tumor (> 0.3 cm, vertical height) in 57 patients, 8 of whom had macroadenomas (> or = 1.1 cm). Visual field loss occurred in 6 of 8 primiparous patients, all with adenomas greater than 1.1 cm (range, 1.2 to 2.5 cm). None of the 57 patients (95% CI, 0% to 6.3%) with a microadenoma or presumed microadenoma of 1 cm or smaller developed visual loss after as many as four full-term pregnancies.
Conclusions: The risk for developing visual loss during single or multiple pregnancies in patients with microadenomas was small. Six of eight pregnant women with macroadenomas, however, developed visual field loss during pregnancy.