Background Ramadan fasting (RF) is mandatory for all healthy Muslims in the ninth month of Islamic calendar. Pregnant women are exempt from fasting but many willfully practise it. There are concerns that fasting during pregnancy is harmful to the fetus but there are no firm recommendations regarding its safety. Objectives To provide a systematic review on the effects of RF on fetal health. Search Strategy We conducted literature search for peer-reviewed articles through Ovid MEDLINE, PubMed, SCOPUS, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) until 31 December 2021. Selection Criteria All case-control and observational cohort studies that reported on fetal outcomes of pregnant women who underwent RF for at least 1 day at any point of time during pregnancy are included. Data Collection and Analysis Two researchers independently reviewed the eligibility of all studies. A third researcher resolved any conflict between researchers. Findings are extracted from eligible papers and presented as narratives. Main Results 18 articles are included based on eligibility criteria, with a total sample size of 3,213,070. There are studies demonstrating negative associations between RF and neonatal weight, amniotic fluid index, preterm birth and growth parameters mainly during second and third trimesters, but those evidences are not strongly supported. Conclusion There is limited data to elucidate the relationship between RF and fetal health, hence the need for more studies to provide better understanding. Funding None. Keywords Ramadan fasting, pregnant women, fetal outcomes.