marginally significantP = 0.05
A marginally significant association was found in retrospective cohorts (OR = 1.78, 95% CI: 1.00–3.17, P = 0.05, I 2 = 91%), whereas no significant associations were identified in women aged >32 years (OR = 2.08, 95% CI: 0.89–4.83, P = 0.09, I 2 = 99%) or small-sample studies (<1,000 participants, OR = 1.68, 95% CI: 0.54–5.22, P = 0.37, I 2 = 69%).