Impacts of Ramadan fasting during pregnancy on pregnancy and birth outcomes: An umbrella review

Abstract

Background: Despite a large number of primary research studies, and systematic and narrative reviews, there is no consensus on the impact of fasting during Ramadan while pregnant on pregnancy and birth outcomes. Currently, there is no evidence-based guideline for Muslim women regarding Ramadan fasting during pregnancy and clinicians cannot provide firm recommendations.

Objectives: To review the current evidence regarding the impact of Ramadan fasting during pregnancy on pregnancy and birth outcomes.

Search strategy: We conducted an umbrella review of all systematic and narrative reviews examining the impacts of fasting during Ramadan while pregnant on pregnancy and birth outcomes by searching PubMed, CINAHL, and Cochrane Registry of Systematic Reviews databases between November 2023 and February 2024.

Selection criteria: We included all systematic and narrative reviews examining the impacts of Ramadan fasting on pregnancy and birth outcomes. The primary outcome was the change in birth weight, gestational age at birth, fetal growth indices, and Apgar score as well as the risk of delivery by cesarean section and the risks of gestational diabetes and pre-eclampsia.

Data collection and analysis: We summarized the data using narrative synthesis and descriptive statistics as appropriate. This study was registered with PROSPERO, ID: CRD42023478819.

Main results: Out of 943 published reports identified across all database searches, 13 systematic and narrative reviews were included, of which three were systematic reviews with meta-analysis, six were systematic reviews without meta-analysis, and the remaining four were narrative reviews. There is no sufficient evidence that Ramadan fasting during pregnancy may reduce gestational age at birth or increase the risk of preterm birth (PTB). There is little evidence to support the hypothesis that maternal Ramadan fasting may reduce birth weight or increase the risk of low birth weight (LBW). Systematic reviews showed pooled estimates of odds ratios ranging between 0.93 (95% confidence interval [CI] 0.60-1.44) and 0.99 (95% CI 0.72-1.37) for PTB, and between 1.05 (95% CI 0.87-1.26) and 1.37 (95% CI 0.74-2.53) for LBW. There is no sufficient evidence that Ramadan fasting during pregnancy may increase the risk of delivery by cesarean section, gestational diabetes, or the risk of pre-eclampsia. None of the reviews reported evidence regarding the impacts of fasting during pregnancy on rare but clinically significant pregnancy and birth outcomes such as stillbirth, miscarriage, congenital anomalies, or neonatal deaths.

Conclusion: There is little evidence that Ramadan fasting during pregnancy can negatively impact pregnancy and birth outcomes. Primary research studies on this issue suffered from significant methodologic limitations and systematic reviews showed significant heterogeneity for several pregnancy and birth outcomes. High-quality primary research studies that collect data on multiple confounders and effect modifiers are needed to investigate this issue and help reaching evidence-based recommendations.

Keywords: Ramadan; birth outcome; birth weight; fasting; pregnancy; preterm birth.