A critical systematic review and meta-analyses of risk factors for fertility problems in a globalized world

Globally, fertility awareness efforts include well-established risk factors for fertility problems. Risks disproportionately affecting women in the Global South, however, are neglected. To address this gap, we conducted a systematic review and meta-analyses of relevant risk factors to examine the association between risk factors and fertility problems. MEDLINE, Embase, Cochrane Library, regional databases and key organizational websites were used. Three authors screened and extracted data independently. Studies assessing exposure to risk (clinical, community-based samples) were included, and studies without control groups were excluded. Outcome of interest was fertility problems, e.g. inability to achieve pregnancy, live birth, neonatal death depending on study. The Newcastle-Ottawa Scale was used to assess study quality. A total of 3843 studies were identified, and 62 were included (58 in meta-analyses; n = 111,977). Results revealed the following: a ninefold risk of inability to become pregnant in genital tuberculosis (OR 8.91, 95% CI 1.89 to 42.12); an almost threefold risk in human immunodeficiency virus (OR 2.93, 95% CI 1.95 to 4.42) and bacterial vaginosis (OR 2.81, 95% CI 1.85 to 4.27); a twofold risk of tubal-factor infertility in female genital mutilation/cutting-Type II/III (OR 2.06, 95% CI 1.03 to 4.15); and postnatal mortality in consanguinity (stillbirth, OR 1.28, 95% CI 1.04 to 1.57; neonatal death, OR 1.57, 95% CI 1.22 to 2.02). It seems that risk factors affected reproductive processes through multiple pathways. Health promotion encompassing relevant health indicators could enhance prevention and early detection of fertility problems in the Global South and disproportionately affected populations. The multifactorial risk profile reinforces the need to place fertility within global health initiatives.