Earlier childbirth ups risk of frailty later in life

Women who give birth at a young age are more likely to experience frailty in midlife and beyond, as reported in a study.

Researchers used data from the National Health and Nutrition Examination Survey (NHANES; 1999–2018) in the US and included 10,828 women (age ≥45 years). The women completed a standardized reproductive health questionnaire, which detailed age at first birth. Meanwhile, frailty was measured using a 53-item frailty index, with a score >0.21 defining the diagnosis.

For the analysis, survey-weighted logistic regression models were used to examine the association between age at first birth and the prevalence of frailty, with a survey-weighted restricted cubic spline (RCS) model applied to determine the presence of a dose–response effect. Mediation analyses were also conducted to assess the mediated effects of education levels, family poverty income ratio, and parity on the association. Finally, sensitivity and subgroup analyses were performed to establish the robustness of the findings.

A total of 3,828 women (35.4 percent) received a diagnosis of frailty. Compared with the women who had their first childbirth at 33–35-years (reference), those who had theirs at a younger age had greater odds of frailty (<18 years: odds ratio [OR], 3.02, 95 percent confidence interval [CI], 1.89–4.83; 18–20 years: OR, 2.32, 95 percent CI, 1.54–3.50; 21–23 years: OR, 1.83, 95 percent CI, 1.19–2.81; 24–26 years: OR, 1.64, 95 percent CI, 1.07–2.53).

On the other hand, there was no association between the following age groups and the risk of later frailty: 27–29, 30–32, or >35 years.

In the subgroup of women who had their first childbirth at age ≤32 years, the association between age at birth and later frailty was partly mediated by education levels (23.4 percent), family poverty income ratio (32.4 percent), and parity (18.3 percent; p<0.001 for all). This means that women with higher education levels, higher family income, and fewer children were less likely to experience frailty even if they had their first childbirth at a younger age.