First childbirth at older age protects against POAG in postmenopausal women
Postmenopausal women having their first childbirth at the age of 27 years or older have a lower risk of developing primary open-angle glaucoma (POAG) compared with those who give their first birth at the age of 20 years or younger, a study suggests. Furthermore, parity significantly moderates the observed association between age at first childbirth and POAG.
Researchers looked at 4,057 postmenopausal women aged ≥50 years from the fifth Korea National Health and Nutrition Examination Survey from 2010 to 2012. The mean age at first childbirth was 23.7 years. The overall POAG prevalence was 3.4 percent and was lowest among women whose first childbirth was between the ages of 27 and 44 years (1.8 percent).
Logistic regression and mediation analyses revealed that compared with women who had an early first childbirth (between the ages of 13 and 20 years), those who had a late first childbirth (between the ages of 27 and 44 years) were 75 percent less likely to develop POAG (odds ratio [OR], 0.25; 95 percent CI, 0.10 to 0.65).
Late first delivery was particularly associated with reduced risk of POAG (direct effect OR, 0.57; 95 percent CI, 0.39 to 0.83; total effect OR, 0.85; 0.74 to 0.98). However, lower parity among women with late first delivery attenuated the effect of age at first childbirth on POAG (indirect effect OR, 1.50; 1.11 to 2.02).
The present data suggest that women who delivered their first infants at younger ages should be screened for POAG when they reach postmenopausal age, researchers said.
Pregnancy and childbirth alter the physiology of the female body. It is speculated that physiological changes during pregnancy at a later age might reduce the risk of POAG. Oxytocin responses to breastfeeding at a later age, for instance, might inhibit inflammation, impair wound healing and suppress stress-associated activation of the interleukin network, which could improve neurologic conditions in the retinal ganglion cells in response to stress and thus promote the cells’ survival. [Front Immunol 2016;7:693; Invest Ophthalmol Vis Sci 2003;44:5206-5211]