Effect of Childbirth Age on Bone Mineral Density in Postmenopausal Women

BACKGROUND: In postmenopausal women, there is rapid bone loss due to estrogen depletion. In women, reproductive factors such as age at menarche, breastfeeding, and parity are considered risk factors of osteoporosis. Many reports suggest that obesity is associated with a reduced risk of osteoporosis. This nationwide, population-based study aims to identify the association between maternal age and osteoporosis risk in postmenopausal women of different obesity classifications. METHODS: We assessed data from the Korean National Health and Nutrition Examination Survey 2010–2012. The study included 1,328 postmenopausal women, after excluding women with missing data for reproductive history among 4,546 postmenopausal women in the survey. Multivariate regression was used to identify the association between childbirth age and postmenopausal bone mineral density after adjustments for confounding factors. RESULTS: The prevalence of postmenopausal osteoporosis was 35.24% (n = 468). After dividing the subjects into obese and non-obese groups based on body mass index (BMI) and waist circumference, there were significant differences between non-osteoporosis and osteoporosis groups with regard to age at first childbirth, age at last childbirth, and parity in the BMI-based general obesity group. The prevalence of osteoporosis was highest in women older than 35 years old at last childbirth. The prevalence of osteoporosis was also greater in women with parity ≥ 4 compared to those with lower parity levels. CONCLUSION: Postmenopausal women of older age at last childbirth and higher parity were at increased risk of osteoporosis in the BMI-based non-general obesity group.

Impact of Maternal Age of 40 Years or Older on Pregnancy Outcomes / 대한주산의학회잡지

OBJECTIVE: The aim of this study was to examine the effects of maternal age on perinatal and obstetric outcomes with respect to maternal age older than 40 years. METHODS: A retrospective review of maternal and newborn medical records of women who delivered their babies in the hospitals of the Catholic University of Korea between January 1, 2000 and July 1, 2005 was conducted to compare pregnancy complications and perinatal outcomes in three age groups; women aged 25~29 years (group A; n=214), those aged 35~39 years (group B; n=276), and those aged 40 years and older (group C; n=347). RESULTS: The incidences of GDM (gestational diabetes mellitus), preterm birth and cesarean section in group C were by far the greatest among the three groups. The incidence of postterm delivery in group A was the highest among the three groups. Previous cesarean section and elderly gravida were the most frequent causes of cesarean section in group C. The incidences of low birth weight (<2,500 g) and the NMICU(neonatal medical intensive care unit) admission rate in group C were higher than those in group B, but not significantly different from those in group A. CONCLUSION: Maternal ages of 35~39 years do not appear to be associated with adverse perinatal and obstetrical outcomes. Maternal ages of over 40 years influence the incidences of PIH (pregnancy induced hypertension), GDM, preterm birth, cesarean section, placenta previa, low birth weight and NMICU admission.