Prenatal Risk Assessment for Preterm Birth in Low-Resource Settings: Infection

Abstract

Maternal infections are a risk factor for preterm birth (PTB); 40% to 50% of PTBs are estimated to result from infection or inflammation. Higher infection rates are reported in low- and middle-income countries (LMIC), and over 80% of PTBs occur in these settings. Global literature was synthesised to identify infections whose prevention or treatment could improve maternal and neonatal health outcomes and/or prevent mother-to-child transmission of infections. Best evidenced risk factors for PTB were maternal infection with human immunodeficiency virus (HIV) (OR2.27; 95%CI: 1.2–4.3), syphilis (OR2.09; 95%CI:1.09–4.00), or malaria (aOR3.08; 95%CI:1.2–4.3). Lower certainty evidence identified increased PTB risk with urinary tract infections (OR1.8; 95%CI: 1.4–2.1), sexually transmitted infections (OR1.3; 95%CI: 1.1–1.4), bacterial vaginosis (aOR16.4; 95%CI: 4.3–62.7), and systemic viral pathogens. Routine blood testing and treatment are recommended for HIV, hepatitis B virus, and syphilis, as well as for malaria in areas with moderate to high transmission. In high-risk populations and asymptomatic or symptomatic disease, screening for lower genital tract infections associated with PTB should be offered at the antenatal booking appointment. This should inform early treatment and management. Heath education promoting pre-pregnancy and antenatal awareness of infections associated with PTB and other adverse pregnancy outcomes is recommended.