Methodology
The systematic review is structured according to the Preferred Reporting
Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 protocol
and checklist.12 The protocol of this review has been
registered with the International Prospective Register of Systematic
Reviews (PROSPERO) (CRD42021254301).
2.1 Search strategy
We searched the following electronic database sources for relevant
articles according to the search strategy: Ovid MEDLINE, PubMed, SCOPUS,
EMBASE and CENTRAL for peer-reviewed articles published until 31st
December 2021. The following combination of Medical Subject Heading
(MeSH) terms and keywords was used: (‘fasting’ or ‘intermittent fasting’
or ‘diet restriction’ or ‘Ramadan’ or ‘Muslim’ or ‘Islam’) and (‘fetal
movement’ or ‘fetal wellbeing’ or ‘fetal development’ or ‘biophysical
profile’) and (‘pregnancy’ or ‘pregnant women’ or ‘expectant mother’).
Search was restricted to ‘human studies’ and English language where
possible. The searches conducted in all e-databases are provided as
Supplementary Table S1.
2.2 Study selection
The article selection process was facilitated using Covidence
software.13 The articles obtained from the database
searches were imported to Covidence, where duplicated records were
deleted. A two-stage screening process was utilized in our study
selection process. At the first screening stage, titles and abstracts
were screened according to inclusion and exclusion criteria. Potential
articles were included, and studies that cannot be excluded based on
title/abstract underwent the second stage of screening. Full texts were
retrieved and again screened in the second stage according to inclusion
and exclusion criteria.
All case-control studies and observational cohorts (prospective or
retrospective) that reported on fetal movements of pregnant women who
underwent RF for at least 1 day at any point of time during pregnancy
are included. For the purpose of this review, fasting is defined as RF
which is an Islamic rule that requires Muslims to have total abstinence
from food and water from sunrise to sunset for a consecutive period of
29-30 days.14 On the other hand, fetal movement is
defined as the fluttering movements of a fetus perceived by a pregnant
woman at around 20 weeks of pregnancy, which indicates the fetus’s
growth in size and strength.15
Grey literature, conference proceedings, theses, reviews,
non-peer-reviewed monographs, books, book chapters, study protocols,
case studies, and cross-sectional studies were excluded. We excluded
studies conducted in vitro or in vivo, single-armed or cohort studies
with no comparator group, and studies where fasting duration during
Ramadan is less than a day.
Two researchers independently reviewed, discussed, and agreed upon the
eligibility of all studies. A third researcher resolved any conflict in
the agreement between the researchers. We did a manual search of the
reference lists of the included articles for other relevant studies not
found in the database search.
2.3 Data extraction and synthesis
Eligible papers are
categorized in a Google sheet to provide clarity. The study origin, the
mean age of participants, study setting, trimester, type of fasting,
outcome reported, and most important findings are extracted from the
final eligible papers. As this is a qualitative synthesis, the findings
are presented as narratives, including tables and figures to aid in data
presentation where appropriate.
2.4 Quality assessment
Two researchers conducted quality assessment for the quantitative
studies using the Newcastle-Ottawa Scale (NOS)16checklist independently. Similar to the screening process, a third
researcher acted as a conflict resolver.
Results
3.1 Study selection and characteristics
We identified 1,366 records through electronic database searches and 8
records through manual searching. A total of 216 duplicate records were
removed, and subsequently, the titles and abstracts of 1,158 records
were screened for inclusion. The full texts of 44 articles were reviewed
for eligibility, and finally, 18 studies were included in the review
(Supplementary Table S2). The study selection process is summarized in a
PRISMA 2020 flow diagram (Figure 1).
[insert Figure 1]
The majority of the studies
were conducted in Turkey (33.3%), followed by Iran (16.7%), Canada
(11.1%) and Saudi Arabia (11.1%) (Table 1). Sixteen studies were
published within the last decade. Two-thirds of the studies were of
cohort designs (prospective or retrospective), and all involved RF. Most
of the studies were conducted across all trimesters (38.9%) or in the
second and third trimesters (27.8%). A total of 3,213,070 samples were
reported collectively in the included studies, with mostly the mean
maternal age ranging from 27 and 30 years (50.0%).
[insert Table 1]
According to NOS, the median quality score was 5 (range: 4-6) for
case-control studies and 7 (range: 6-9) for cohorts (Table 2). Overall,
eleven studies (61.1%) scored 7 and above, indicating high quality,
while the other seven (38.9%) scored 4–6, indicating intermediate
quality.
3.2 Effect of fasting on neonatal
outcomes.
Table 3 presents the summary of outcomes that were reported by the
studies included in this review. Thirteen studies (72.2%) reported the
effect of fasting on neonatal weight, followed by six studies (33.3%)
on amniotic fluid index. Five studies (27.8%) reported on biparietal
diameter, estimated fetal body weight, head circumference and fetal
femur length, while gestational age at delivery, preterm birth/delivery
and length were reported by four studies (22.2%). Fewer studies
reported other outcomes like abdominal circumference, biophysical
profile, APGAR score and stillbirth.
[insert Table 3]
3.3 Neonatal weight
Only one study found a significant association between maternal fasting
and neonatal weight.21 The authors reported
significantly lower birth weight in neonates of Ramadan-fasted women
during the second and third trimesters than the control group (3094±467g
vs.202±473 g; P=0.024). Savitri et al.’s study22 among
women who fasted in their first trimester showed a potential reduction
in the birthweight of newborns than of non-fasting mothers. However, the
results were insignificant (-198 g, 95 % CI -447–51,
P=0.12).22
3.4 Amniotic fluid index
(AFI)
The results on AFI were not statistically significant in all but two
studies.24,26 Karateke et al.,25which presented AFI findings for both second and third trimesters
fasting respectively, determined a significant reduction in AFI for
second trimester fasting only (11.4(9.8-14.1)cm vs 16.2(12.6-18.3)cm,
P=0.02). Seckin and colleagues23 noted a significant
decrease in AFI in the fasting group for third trimester fasting
(20.1±11.2cm vs11.5±6.4cm,P<0.001). They concluded that
maternal fasting reduced the interval for development of
oligohydramnios.
Despite showing no significant difference in AFI increase between
fasting and non-fasting groups, Sakar et al.’s32demonstrated a significantly lower increase in AFI of fasting group,
potentially due to higher incidence of dehydration among fasting group,
attributed by longer daytime above 17 hours and high temperatures
between 36°C to 43°C.
3.5 Increase in biparietal diameter
(BPD)
Only one study showed a significant association between both
variables.32 Sakar and colleagues32noted that increase in BPD was significantly different from initial
measurements between fasting and non-fasting groups (9.69±3.07mm
vs10.74±1.99mm,P=0.041) for pregnant women in their second and third
trimesters. Other than Sakar et al.,32 all four
remaining studies reported insignificant findings. Except for Dikensoy
et al.,29,30 three other studies demonstrated that
increase in BPD was greater in non-fasting control
groups.23,25,31
3.6 Increase in estimated fetal body weight
(EFBW)
Findings correlating the increase in EFBW and fasting were not
significant in all articles (P>0.05). In
Karateke’s25 and Sakar’s32 studies,
there were expected greater increases in EFBW in non-fasting groups,
compared to the fasting groups.25,32 However, the
inverse was true for the three remaining
studies.23,29,30,31
3.7 Increase in fetal femur length
(FL)
Only one study showed a significant association between fasting and
increase in fetal FL. Sakar et al.’s32 study showed a
significantly more significant increase in fetal FL in the non-fasting
control group than with second and third trimesters fasting (9.98±1.86mm
vs8.57±2.56mm, P=0.002). As for the remaining articles with
insignificant findings, three studies23,29,30,31 noted
that the increase in fetal FL was lesser in the control groups than in
the study groups, unlike in Karateke et al.,25 which
reported a larger increase in fetal FL in the non-fasting control group.
3.8 Gestational age at
delivery
Only Alwasel’s study19 found a significant association
between RF and gestational age at delivery. The author reported that
girls whose mothers were in their second trimester of pregnancy during
the fasting month endured a shorter gestation period than girls who were
not in utero during Ramadan (39.4weeks vs39.8weeks,P=0.04). The
differences in gestational age at delivery for other trimesters and boys
in general, were not statistically significant.
In two other studies,21,23 mothers who fasted during
pregnancy also experienced a shorter gestational period than pregnant
mothers who did not fast. Contrarily, one study26noted that pregnant women fasted during their third trimester had a
longer gestational age at delivery than their non-fasting counterparts.
3.9 Increase in length, head circumference (HC), and
abdominal circumference
(AC)
In Sakar and colleagues’s study32, second and third
trimesters’ fasting had significant increase on HC in the control group
than study group (39.12±7.42cm vs 35.12±12.22cm, P=0.046). However, the
other articles6,19,28 showed no significant between
fasting and an increase in HC. Alwasel et al.19 also
noted boys’ HC in utero were generally larger than girls’ during
fasting.
Only one study19 showed the length of boys whose
mothers were in their second trimesters of pregnancy was significantly
greater than boys who were not in utero during Ramadan (52.3cm vs
51.1cm, P=0.005). However, no significant association was found between
fasting and babies’ height in three other
studies.6,27,28
All three articles reporting on AC indicated insignificant association
between fasting and increased AC.23,31,32 The increase
in AC was greater in the non-fasting groups in Moradia et
al.31 and Sakar et al.32
3.10 Preterm Birth
According to Tith et al.,33 the risk of preterm birth
is significantly increased when participants fasted during
second-trimester. Arabic-speaking women who fasted between weeks 15 and
21 of gestation and weeks 22 and 27 had 1.33 (95% CI:1.06-1.68) and
1.53 (95% CI:1.21-1.93) times the risk of very preterm birth,
respectively than non-fasting group. When both parents had Arabic mother
tongue and spoke the language at home, RF in weeks 15 to 21 was linked
to 1.38 times the risk of very preterm birth (95% CI:1.03-1.85) and
1.65 times in weeks 22 to 27 (95% CI:1.23-2.21). If compared to
non-Arabic speakers who were pregnant in the same period, the risk
reduced to 1.25 (95% CI:1.02-1.53) and 1.33 (95% CI:1.08-1.63) times
respectively.
Petherick et al.24 and Hossain et
al.28 showed no association between RF and the risk of
preterm birth, even after adjusting for covariables. Awwad and
colleagues21 noted that despite having higher
incidence of preterm birth in the fasting group, the difference was
insignificant.
3.11 Biophysical Profile (BPP)
All study results showed no significant difference between fasting
pregnant women and non-fasting pregnant women.26,29,30In one study,29,30 there was an average score of 7.8
in the fasting group, compared to 7.0 in the control group. However, the
difference was statistically insignificant.
3.12 APGAR Score
Hossain and colleague’s study28 demonstrated that
5-min APGAR score was significantly higher in the fasting group than
non-fasting group (9.00±0.01 vs 8.92±0.53, p=0.044). While the study
showed a similar trend for 1-min Apgar score, the difference was not
significant. In Abd-Allah Rezk et al.’s study26, the
5-min APGAR score for non-fasting group had an average of 8.52±1.1,
while the fasting group had an average of 8.44±1.2. Similarly, in
Karatake et al. ’s study,25 there was insignificant
difference between the two groups for both 1-min and 5-min APGAR scores.
3.13 Stillbirth
In both adjusted and unadjusted models, RF during first and second
trimesters was not associated with risk of early and late stillbirths
when compared to no exposure. Nevertheless, when the data was further
classified according to causes of death, Bernier and
colleagues34 found that Ramadan exposure between weeks
15 to 21 of pregnancy increased the risk of early stillbirth due to
congenital anomaly by 3.96 times (95% CI1.35-11.57). However, this
reported findings has not been adjusted for covariates.
3.14 Other outcomes
Seckin et al.23 reported that a significantly higher
number of participants with normal initial AFI subsequently developed
oligohydramnios (20/82 vs 6/87,P=0.03) in the fasting group. Naderi et
al.17 reported insignificant difference in the rate of
fundal height increment between fasting and non-fasting groups. In
Alwasel et al.’s study,19 there was no significant
association between fasting and chest circumference regardless of baby’s
gender and fasting trimester. In Abd-Allah Rezk et al.’s
study,26 the difference in reactivity of the
non-stress test between fasting and non-fasting groups was
insignificant.
Discussion
4.1 Main Findings
Our study demonstrated few significant findings. RF negatively affected
neonatal weight,21 AFI,23,25gestational age at delivery,19 preterm
birth33 and changes in growth parameters except
abdominal circumference.19,32
We found three other reviews11,35,36 that looked into
the effects of RF during pregnancy on perinatal outcomes. Glazier and
colleagues11 had reported similar outcomes,
specifically preterm birth and birth weight. They found that RF did not
significantly affect the frequency of preterm delivery (OR 0.99,95% CI
0.72-1.37), birth weight (SMD 0.03, 95% CI 0.00-0.05) and proportion of
low-birth-weight babies (OR 1.05,95% CI 0.87-1.26), irrespective of
pregnancy trimesters. Oosterwijk et al.35 and Noshili
et al.36 included data on fetal growth indices and
birth indices. Both reviews inferred that RF has some associations with
fetal growth indices and birth indices but predominantly found in lower
quality studies. Certain included articles23,25,32described lower AFI in the fasting group during second or third
trimester of pregnancy, and BPD, HC and FL32 were
significantly affected by fasting (p<0.05). Only one high
quality study mentioned that mean birth weight was significantly lower
in exposed neonates (108g, p=0.024). Apart from that, differences in
birth indices were statistically insignificant.
4.2 Interpretation
Our findings are consistent with data gathered by the three systematic
reviews,11,35,36 with little supporting evidence that
RF has some associations with poor fetal health. This is because we
discovered that evidence linking RF and changes in certain fetal
outcomes only appeared in one of many articles examining them. Notably,
there is a trend that all significant changes occurred especially when
pregnant women fasted during second or third trimesters. This could be
an important reference point for future studies whereby fasting during
second and third trimesters of pregnancy may result in higher risks of
poor fetal outcomes.
4.3 Strengths and Limitations
Maternal ethnicity and height were not adjusted for in all the articles.
Certain ethnicities are known to have above average height and maternal
height is a strong predictor of offspring nutritional status. Stulp and
colleagues37 mentioned that taller parents have
heavier newborns. Birth weight was found to be both independently and
positively affected by maternal and paternal height, with a 66%
stronger effect ascribed to maternal influence. Inversely, a research
done in Brazil38 showed that adult stature reflects
nutritional status and health processes throughout life. Earlier
research demonstrated that short stature is likely due to combined
genetic and environmental effects, such as nutritional stresses in early
stages of life.39 Short mothers with poorer quality of
life are likely to provide insufficient nutrients to fetuses during
pregnancy, resulting in small-for-gestational-age (SGA)
babies.39 Similarly, mothers who were SGA at birth are
at greater risks of giving birth to SGA offspring.39
Our original intent of this study was to investigate the effects of RF
on fetal movements because it is one of the easiest ways to monitor
fetal growth and activity. Decreased fetal movement may be the first
sign of an underlying pathology and warrants further assessment. We had
to modify the primary objective of this study because there was not
enough data for further analysis. We only found two out of eighteen
included articles that reported fetal movement as an outcome of
measurement in the form of non-stress tests.
Another limitation identified is that most studies are performed in the
Middle East, and less so in Western and Asian countries. Dietary
patterns and cultures differ across countries. It may be a confounding
factor that has not been accounted for during this study. For instance,
Middle Easterners usually consume healthy Mediterranean diet which
mainly consists of whole foods including vegetables, fruits, whole
wheat, legumes, nuts, seafood and spices. Red meat, dairy and processed
food are typically in smaller amounts than a standard Western diet.
Depending on the types of food pregnant mothers eat while breaking fast
during Ramadan, there will be a difference in nutritional components,
which inadvertently affects fetal growth parameters. For this systematic
review, we could not find any article that was based in the Asian
community, therefore it is difficult to translate any evidence into
practical recommendations that are aimed towards Asian lifestyle.
Furthermore, only articles published in the English language and
involved human studies are included. There could be articles not
published in the English language related to our topic but are omitted.
Some articles demonstrated potential health effects of fasting through
animal models. Therefore, they were not included in this study. For
example, Alkhalefah et al.40 reported intermittent
fasting in pregnant Wistar rats induces fetal growth restriction and
down-regulated placental amino acid transport. For these reasons, the
number of articles included in our review was narrowed down, which could
contribute to lower strength of evidence.
Although some individual studies have associated RF with potential
health impacts, we could not perform a meta-analysis to calculate an
overall effect due to limitations of data available. While some outcomes
could not be presented as mean and standard deviation, most are not
available from included studies. Correspondingly, we could not determine
the effect size and heterogeneity of each outcome.
There are two studies36,41 referenced in this review
that looked at long-term consequences of individuals exposed to RF in
utero, including physical traits and cognitive effects. As our study
mainly focuses on short-term or immediate outcomes, those data are
excluded, but they could always be considered for future research
questions.
Conclusion
This systematic review found that there is insufficient data to
associate RF with poor fetal outcomes.
5.1 Implications for Research
While there are negative associations between RF and fetal health, the
findings appeared to be inconsistent across studies. Our review
highlighted the importance of having further prospective research and
outcome-specific retrospective observational studies that take into
account multiple confounding factors to provide a more definitive
evidence. We are hoping that this systematic review could be used as a
guide for future pilot studies across different regions to look at the
effects of RF on fetal health, to provide reassurance and advice to
pregnant mothers who wish to safely practise fasting and avoid any
adverse outcomes.
5.2 Implications for Practice
This systematic review provides recommendation to health professionals
and pregnant women on the safety of RF during pregnancy.
Acknowledgement
None.
Author Contribution
The study was formulated by AKWO, ALY and AJHF. AR carried out the
literature search. ALY and AJHF screened through and selected eligible
studies. Differences in opinion were sorted out by AKWO. AKWO and ALY
extracted data and carried out the data analysis. AKWO and AJHF
performed quality assessment for all included studies. VJTA supervised
the data analysis and write-up of study. All authors were involved in
interpretation of data and revised the article critically.
Conflict of Interests
None declared.
Ethical Approval
None.
References:
- Finnell JS, Saul BC, Goldhamer AC, Myers TR. Is fasting safe? A chart
review of adverse events during medically supervised, water-only
fasting. BMC Complement Altern Med. 2018 Feb 20;18(1):67. doi:
10.1186/s12906-018-2136-6.
- Templeman, I., Gonzalez, J., Thompson, D., & Betts, J. (2020). The
role of intermittent fasting and meal timing in weight management and
metabolic health. Proceedings of the Nutrition Society, 79(1), 76-87.
doi:10.1017/S0029665119000636.
- Britannica, T. Editors of Encyclopaedia. ”Ramadan.” Encyclopedia
Britannica, September 10, 2020.
https://www.britannica.com/topic/Ramadan. Accessed 27 January 2021.
- Leiper, J., Molla, A. & Molla, A. Effects on health of fluid
restriction during fasting in Ramadan. Eur J Clin Nutr 57, S30–S38
(2003). https://doi.org/10.1038/sj.ejcn.1601899.
- Lessan N, Ali T. Energy Metabolism and Intermittent Fasting: The
Ramadan Perspective. Nutrients. 2019 May 27;11(5):1192. doi:
10.3390/nu11051192.
- Ziaee V, Kihanidoost Z, Younesian M, Akhavirad MB, Bateni F,
Kazemianfar Z, Hantoushzadeh S. The effect of ramadan fasting on
outcome of pregnancy. Iran J Pediatr. 2010 Jun;20(2):181-6. PMID:
23056701; PMCID: PMC3446023.
- Frøen JF, Heazell AE, Tveit JV, Saastad E, Fretts RC, Flenady V. Fetal
movement assessment. Semin Perinatol. 2008 Aug;32(4):243-6. doi:
10.1053/j.semperi.2008.04.004.
- Singh G, Sidhu K. Daily Fetal Movement Count Chart : Reducing
Perinatal Mortality in Low Risk Pregnancy. Med J Armed Forces India.
2008 Jul;64(3):212-3. doi: 10.1016/S0377-1237(08)80094-9.
- Warrander LK, Batra G, Bernatavicius G, Greenwood SL, Dutton P, Jones
RL, Sibley CP, Heazell AE. Maternal perception of reduced fetal
movements is associated with altered placental structure and function.
PLoS One. 2012;7(4):e34851. doi: 10.1371/journal.pone.0034851.
- Parveen R, Khakwani M, Latif M, Tareen AU. Maternal and Perinatal
outcome after Ramadan Fasting. Pak J Med Sci. 2020
Jul-Aug;36(5):894-898. doi: 10.12669/pjms.36.5.2612. PMID: 32704259;
PMCID: PMC7372656.
- Glazier JD, Hayes DJL, Hussain S, D’Souza SW, Whitcombe J, Heazell
AEP, Ashton N. The effect of Ramadan fasting during pregnancy on
perinatal outcomes: a systematic review and meta-analysis. BMC
Pregnancy Childbirth. 2018 Oct 25;18(1):421. doi:
10.1186/s12884-018-2048-y. PMID: 30359228; PMCID: PMC6202808.
- Page M J, McKenzie J E, Bossuyt P M, Boutron I, Hoffmann T C, Mulrow C
D et al. The PRISMA 2020 statement: an updated guideline for reporting
systematic reviews BMJ 2021; 372 :n71 doi:10.1136/bmj.n71
- Veritas Health Innovation. Covidence Systematic Review Software.
Melbourne, Australia. Available online: www.covidence.org.
- Erol A, Baylan G, Yazici F. Do Ramadan fasting restrictions alter
eating behaviours? Eur Eat Disord Rev. 2008;16(4):297–301.
- Bryant J, Jamil RT, Thistle J. Fetal Movement. [Updated 2020 Nov
30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls
Publishing; 2021 Jan-. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK470566/.
- Wells G, Shea B, O’Connell D, Peterson J, Welch V, Losos M, Tugwell P:
The Newcastle-Ottawa Scale (NOS) for assessing the quality of
nonrandomised studies in meta-analyses.
2013, http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp.
- Naderi T, Kamyabi Z. Determination of fundal height increase in
fasting and non-fasting pregnant women during Ramadan. Saudi Med J.
2004 Jun;25(6):809-10. PMID: 15195219.
- Alwasel SH, Abotalib Z, Aljarallah JS, Osmond C, Alkharaz SM, Alhazza
IM, Badr G, Barker DJ. Changes in placental size during Ramadan.
Placenta. 2010 Jul;31(7):607-10. doi: 10.1016/j.placenta.2010.04.010.
Epub 2010 Jun 2. PMID: 20621763.
- Alwasel SH, Abotalib Z, Aljarallah JS, Osmond C, Alkharaz SM, Alhazza
IM, Harrath A, Thornburg K, Barker DJ. Sex differences in birth size
and intergenerational effects of intrauterine exposure to Ramadan in
Saudi Arabia. Am J Hum Biol. 2011 Sep-Oct;23(5):651-4. doi:
10.1002/ajhb.21193. Epub 2011 May 31. PMID: 21630372.
- Ozturk E, Balat O, Ugur MG, Yazıcıoglu C, Pence S, Erel Ö, Kul S.
Effect of Ramadan fasting on maternal oxidative stress during the
second trimester: a preliminary study. J Obstet Gynaecol Res. 2011
Jul;37(7):729-33. doi: 10.1111/j.1447-0756.2010.01419.x. Epub 2011 Mar
9. PMID: 21736666.
- Awwad J, Usta IM, Succar J, Musallam KM, Ghazeeri G, Nassar AH. The
effect of maternal fasting during Ramadan on preterm delivery: a
prospective cohort study. BJOG. 2012 Oct;119(11):1379-86. doi:
10.1111/j.1471-0528.2012.03438.x. Epub 2012 Jul 25. PMID: 22827751.
- Savitri AI, Yadegari N, Bakker J, van Ewijk RJ, Grobbee DE, Painter
RC, Uiterwaal CS, Roseboom TJ. Ramadan fasting and newborn’s birth
weight in pregnant Muslim women in The Netherlands. Br J Nutr. 2014
Nov 14;112(9):1503-9. doi: 10.1017/S0007114514002219. Epub 2014 Sep
18. PMID: 25231606.
- Seckin KD, Yeral MI, Karslı MF, Gultekin IB. Effect of maternal
fasting for religious beliefs on fetal sonographic findings and
neonatal outcomes. Int J Gynaecol Obstet. 2014 Aug;126(2):123-5. doi:
10.1016/j.ijgo.2014.02.018. Epub 2014 Apr 18. PMID: 24792406.
- Petherick ES, Tuffnell D & Wright J. Experiences and outcomes of
maternal Ramadan fasting during pregnancy: results from a sub-cohort
of the Born in Bradford birth cohort study. BMC Pregnancy
Childbirth. 2014 Sep 26;14:335.https://doi.org/10.1186/1471-2393-14-335.
- Karateke A, Kaplanoglu M, Avci F, Kurt RK, Baloglu A. The effect of
Ramadan fasting on fetal development. Pak J Med Sci. 2015
Nov-Dec;31(6):1295-9. doi: 10.12669/pjms.316.8562. PMID: 26870085;
PMCID: PMC4744270.
- Abd-Allah Rezk M, Sayyed T, Abo-Elnasr M, Shawky M, Badr H. Impact of
maternal fasting on fetal well-being parameters and fetal-neonatal
outcome: a case-control study. J Matern Fetal Neonatal Med. 2016
Sep;29(17):2834-8. doi: 10.3109/14767058.2015.1105955. Epub 2015 Nov
2. PMID: 26453375.
- Sakar MN, Balsak D, Verit FF, Zebitay AG, Buyuk A, Akay E, Turfan M,
Demir S, Yayla M. The effect of Ramadan fasting and maternal
hypoalbuminaemia on neonatal anthropometric parameters and placental
weight. J Obstet Gynaecol. 2016 May;36(4):483-6. doi:
10.3109/01443615.2015.1086989. Epub 2015 Oct 14. PMID: 26467047.
- Hossain N, Samuel M, Mughal S, Shafique K. Ramadan Fasting: Perception
and maternal outcomes during Pregnancy. Pak J Med Sci.
2021;37(5):1262-1267. doi:https://doi.org/10.12669/pjms.37.5.4109
- Dikensoy E, Balat O, Cebesoy B, Ozkur A, Cicek H, Can G. Effect of
fasting during Ramadan on fetal development and maternal health. J
Obstet Gynaecol Res. 2008 Aug;34(4):494-8. doi:
10.1111/j.1447-0756.2008.00814.x. PMID: 18937702.
- Dikensoy E, Balat O, Cebesoy B, Ozkur A, Cicek H, Can G. The effect of
Ramadan fasting on maternal serum lipids, cortisol levels and fetal
development. Arch Gynecol Obstet. 2009 Feb;279(2):119-23. doi:
10.1007/s00404-008-0680-x. Epub 2008 May 17. PMID: 18488237.
- Moradia M. The effect of Ramadan fasting on fetal growth and Doppler
indices of pregnancy. Journal of research in medical sciences : the
official journal of Isfahan University of Medical Sciences.
2011;16:165-9.
- Sakar MN, Gultekin H, Demir B, Bakir VL, Balsak D, Vuruskan E, Acar H,
Yucel O, Yayla M. Ramadan fasting and pregnancy: implications for
fetal development in summer season. J Perinat Med. 2015
May;43(3):319-23. doi: 10.1515/jpm-2013-0289. PMID: 24810552.
- Tith RM, Bilodeau-Bertrand M, Lee GE, Healy-Profitós J, Auger N.
Fasting during Ramadan Increases Risk of Very Preterm Birth among
Arabic-Speaking Women. J Nutr. 2019 Oct 1;149(10):1826-1832. doi:
10.1093/jn/nxz126. PMID: 31198942.
- Bernier J, Bilodeau-Bertrand M, Djeha A, Auger N. Ramadan exposure
during early pregnancy and risk of stillbirth in Arab women living in
Canada. Paediatr Perinat Epidemiol. 2021 Nov;35(6):689-693. doi:
10.1111/ppe.12761. Epub 2021 May 26. PMID: 34080705.
- Oosterwijk VN, Molenaar JM, van Bilsen LA, Kiefte-de Jong JC. Ramadan
Fasting during Pregnancy and Health Outcomes in Offspring: A
Systematic Review. Nutrients. 2021 Oct;13(10):3450.
- Noshili AI, Jamshed M, Hamdi AM, Noshaily AJ, Zammar AMA, Jabbari MYA,
Khudhayr SY, Alshakarah NF, Almutairi SM, Sale AJ. Effects of Fasting
in Ramadan on Pregnancy Outcome: Systematic Review. International
Journal of Clinical Skills. 2022 May 30;16(4).242. DOI:
10.37532/1753-0431
- Stulp G, Verhulst S, Pollet TV, Nettle D, Buunk AP. Parental height
differences predict the need for an emergency caesarean section.PLoS One. 2011;6(6):e20497. doi:10.1371/journal.pone.0020497
- Britto RPdA, Florêncio TMT, Benedito Silva AA, Sesso R, Cavalcante JC,
Sawaya AL. Influence of Maternal Height and Weight on Low Birth
Weight: A Cross-Sectional Study in Poor Communities of Northeastern
Brazil . PLOS ONE 2013 Nov 11;8(11): e80159.
https://doi.org/10.1371/journal.pone.0080159
- Khatun W, Rasheed S, Alam A, Huda TM, Dibley MJ. Assessing the
Intergenerational Linkage between Short Maternal Stature and
Under-Five Stunting and Wasting in Bangladesh. Nutrients.
2019;11(8):1818. Published 2019 Aug 7. doi:10.3390/nu11081818
- Alkhalefah A, Dunn WB, Allwood JW, Parry KL, Houghton FD, Ashton N,
Glazier JD. Maternal intermittent fasting during pregnancy induces
fetal growth restriction and down-regulated placental system A amino
acid transport in the rat. Clinical Science. 2021 Jun
11;135(11):1445-66.
- Mahanani MR, Abderbwih E, Wendt AS, Deckert A, Antia K, Horstick O,
Dambach P, Kohler S, Winkler V. Long-Term Outcomes of in Utero Ramadan
Exposure: A Systematic Literature Review. Nutrients. 2021 Dec
17;13(12):4511. doi: 10.3390/nu13124511. PMID: 34960063; PMCID:
PMC8704584.
Table S1: Search strategies
OVID Medline