Introduction:
Globally, caffeine is the most commonly consumed addictive substance with an estimated prevalence of about 80%¹. Excessive intake is not recommended, especially during the perinatal period due to reported adverse effects². Research on breastfeeding is scarce with the majority focusing on the potential impacts on the breastfeeding child³. We aimed to investigate the prevalence of maternal caffeine consumption during the perinatal period and the associations between caffeine intake and breastfeeding duration.

Material and Methods:
The online databases PubMed/Medline, EMBASE, CINAHL and Google Scholar were systematically searched for relevant articles published between 1993-2023 following PRISMA guidelines. Keywords were: “maternal”, “caffeine consumption”, “caffeine intake”, “breastfeeding initiation”, “breastfeeding duration”, “breastfeeding cessation’’, “lactation’’.

Results:
Five cohort studies met the inclusion criteria. Mattar et al.⁴ and Tigka et al.⁵ reported longer duration of breastfeeding in association with maternal caffeine consumption in their studies (mean±SD: 5.32 ± 5.66; p=0.031 and β=0.09; SE: 0.04; p=0.045, respectively). On the contrary, caffeine was negatively associated with longer duration of breastfeeding in two prospective studies conducted by Clifford et al. and Rebhan et al. (HR=1.34; 95% CI: 1.06-1.70 and OR=1.49; 95% CI: 1.25-1.79, p<0.001 respectively)^6,7. Finally, a Swedish study recruiting 10205 infants did not demonstrate any associations between maternal caffeine intake and breastfeeding duration⁸. The prevalence of antenatal caffeine consumption ranged from 52.6 to 86.6%^4-7 and from 49.3 to 84.8% during lactation^4,5,7.

Conclusions:
The results of the included studies are contradictory, thus preventing safe conclusions on this issue and the provision of evidence-based advice to breastfeeding mothers. Evidence on correlations between maternal caffeine consumption and breastfeeding duration is insufficient, highlighting the need for further research.