Study / Country Study design N Trimester Mean maternal age (y) Type of fasting Main finding
Naderi (2004) Iran
Case-control
101
Second and third
Case = 28.3 (5.5) Control = 28.8 (5.7)
Ramadan fasting
No significant difference in fundal height increase in 5 performed examinations, and mean BW between study groups.
Dikensoy (2008, 2009) Turkey
Prospective cohort
65
Second and third
Fasting = 24.0 (5.3) Control = 26.0 (4.2)
Ramadan fasting
No difference in increase in BPD, FL, EFBW, and fetal BPP and AFI between the groups. Fetal BPP and AFI were within normal ranges in both groups.
Alwasel et al (2010) Saudi Arabia
Retrospective cohort
7083
First, second and third
29.5
Ramadan fasting
No difference in birth weight between babies in utero and not in the utero during Ramadan regardless of the trimester and gender. No difference in other outcomes (BW, HC, CC), between babies in utero and not in utero during Ramadan, regardless gender.
Ziaee (2010) Iran
Retrospective cohort
189
First, second and third
25.9
Ramadan fasting
No significant increase in risk of low BW with fasting in the first trimester. No significant differences between BW, length, HC and number of days on fasting.
Alwasel (2011) Saudi Arabia
Retrospective cohort
967
First, second and third
Boys = 29.3 (6.1) Girls = 29.5 (5.9)
Ramadan fasting
Babies who were boys and were in the second trimester of gestation during Ramadan were significantly longer at birth than babies that were not in utero during Ramadan and baby girls. Girls who were in their second trimester of gestation during Ramadan had significantly shorter gestation periods.
Moradia (2011) Iran
Case-control
52
Second and third
Fasting = 28.3 (5.5) Non-fasting = 28.3 (5.5)
Ramadan fasting
No significant difference between fasting and non-fasting groups in terms of increase in BPD, FL, AC, fetal weight (fetal weight gain, increase in gestational age related to BPD, FL and AC, and changes in AFI.
Ozturk (2011) Turkey
Prospective cohort
72
Second
Fasting = 30.1 Control = 29.5
Ramadan fasting
No significant difference in birth weight between study groups.
Awwad (2012) Lebanon
Prospective cohort
402
Second and third
Fasting = 29.7 (5.2) Control = 30.0 (5.4)
Ramadan fasting
Neonates of fasted women had lower BW than controls. No significantly different in preterm delivery rates, small for gestational age, and gestational age at delivery.
Petherick (2014) United Kingdom
Prospective cohort
300
First, second and third
Fasted = 27.6 (4.7) None = 29.0 (5.4)
Ramadan fasting
No significant association between fasting, preterm birth and low BW before and after adjustment for other covariables
Savitri (2014) Netherlands
Prospective cohort
130
First, second and third
Fasting < half a month = 28.9 (4.9) Fasting > half a month = 28.9 (4.7) Non-fasting = 29.3 (4.2)
Ramadan fasting
Significantly lower BW of new-borns of women who fasted in the first trimester than non-fasting women, after adjustment for covariates. No differences in BW found in the second or third trimester. Lowest BW in new-borns of women who fasted more than half a month, but no significant interaction suggesting the opposing effects of fasting per trimester of exposure.
Seckin (2014) Turkey
Prospective cohort
169
Third
Fasting = 24.0 (4.2) Non-fasting = 26.1 (5.9)
Ramadan fasting
Significantly greater mean BW and change in AFI in fasting women compared to non-fasting group. The number of patients who initially had a normal amniotic fluid measurement and subsequently developed oligohydramnios was significantly higher in the religious fasting group than in the non-fasting group. No significant differences in changes in BPD, AC, FL, fetal weight gain, changes in age-BPD, age-FL, age-AC, and mean gestational age at delivery between groups.
Karateke (2015) Turkey
Prospective cohort
240
First, second and third
26.2 (3.7)
Ramadan fasting
Lower AFI in fasting than without fasting among pregnant women in the second trimester. No significant differences between the groups in terms of increase of fetal BPD, increase of fetal femur length, increase of fetal EFBW, AFI in first and third trimesters, newborn BW, rate of low BW, and Apgar score.
Sakar (2015) Turkey
Case-control
166
Second and third
Fasting = 26.8 (5.2) Non-fasting = 28.4 (5.0)
Ramadan fasting
Significant difference in increase in BPD, HC, FL, increase in gestational age related to HC and FL between groups. Increase in AFI was significant in the non-fasting group only. No significant differences in increase in AC, gestational age related to BPD, AC and fetal weight gain between groups.
Abd-Allah Rezk et al (2016) Egypt
Case-control
450
Third
Fasting = 23.2 (4.3) Non-fasting = 23.0 (4.0)
Ramadan fasting
No significant differences in reactivity of NST, modified biophysical scores, gestational age at delivery, neonatal weight, 5-min Apgar scores and admission to neonatal intensive care unit. Short-term maternal fasting has no deleterious effect on fetal well-being parameters or neonatal outcome.
Sakar (2016) Turkey
Case-control
338
Third
Fasting = 28.0 (5.8) Non-fasting = 27.6 (5.5)
Ramadan fasting
No significant differences in mean BW, height and HC between groups.
Tith (2019) Canada
Retrospective cohort
3123508
First, second and third
NA
Ramadan fasting
Ramadan fasting in week 15-21 and 22-27 of gestation were associated with greater risk of very preterm birth.
Bernier (2021) Canada
Retrospective cohort
78623
First and second
35.0
Ramadan fasting
Ramadan fasting has no significant association with the risk of early or late stillbirth overall.
Hossain (2021) Pakistan
Prospective cohort
215
Third
Fasted = 26.54 (4.82) Not fasted = 26.84 (5.06)
Ramadan fasting
5-min Apgar scores are significantly higher in the fasted group than the non-fasted group. However, there is no significant difference in rate of preterm delivery and anthropometric measurements between both groups