Fasting During Pregnancy: What You Need to Know

Pregnancy is a special time filled with joy and preparation, yet it brings significant health considerations during religious observances such as Ramadan. In Islam, pregnant women are explicitly exempt from fasting to protect both maternal and fetal health. Nevertheless, many women choose to fast due to faith and tradition. If you are wondering whether it is safe and what the science says, you are not alone. Based on the latest evidence, let’s explore the topic with a focus on your well-being.

The Science Behind Ramadan Fasting in Pregnancy

Research on this topic is growing but remains limited—consisting mostly of observational studies and reviews rather than large-scale trials. A meta-analysis involving over 31,000 pregnancies found that Ramadan fasting did not significantly affect birth weight or the risk of preterm birth (odds ratio 0.99, 95% CI 0.72-1.37).[1] Another systematic review confirmed this, showing no clear link to low birth weight but noting that placental weight might be slightly lower in fasting mothers (standardized mean difference -0.94, 95% CI -0.97 to -0.90).[1] These findings suggest that in healthy pregnancies, short-term outcomes—like the baby’s size at birth—are generally similar whether you fast or not.

Potential Risks and Long-Term Effects

However, the picture is not entirely clear. Some studies point to potential risks, especially during the second trimester. For example, fasting between weeks 15-27 may increase the risk of very preterm birth (28-31 weeks) by 1.53 times among Arabic-speaking women.[2] Long-term effects on the offspring are less researched but raise concerns: exposure during early pregnancy (pre-conception or first trimester) may increase the risk of shorter stature, learning disabilities, or even under-five mortality in childhood.[3] A review of 43 studies found overall weak evidence, with only a few high-quality studies noting possible effects on fetal growth or cognitive outcomes, but nothing is definitive.[4]

Gestational Diabetes and Glucose Control

On the other hand, there may be some positive aspects. A study in Iraq showed lower rates of gestational diabetes in fasting mothers (2.6% vs. 8.3% in non-fasters), possibly due to better blood sugar control from timed eating.[5] However, this is not consistent across all research, and for women with pre-existing or gestational diabetes, guidelines strongly advise against fasting due to risks of hypoglycemia or ketoacidosis.[6][7]

Who Should Be Extra Cautious?

Not all pregnancies are the same. Conditions like diabetes, hypertension, or a history of preterm labor can make fasting riskier—potentially causing dehydration, nutrient deficiencies, or stress on your body.[8] Even in healthy pregnancies, the duration of the fast (e.g., 12-18 hours a day), the trimester, and your overall nutrition matter. Studies show that energy intake drops during fasting but recovers at night; however, water and key nutrients like iron or folate may remain low without balanced meals.[9]

In infants of mothers with gestational diabetes, one study found that fasting might reduce neonatal hypoglycemia but could increase the risk of hyperbilirubinemia (jaundice) fourfold, especially during the third trimester.[10] In summary: the evidence is mixed and often of low quality, meaning it is not a “green light” for everyone.

Practical Tips and When to Consult Your Doctor

If you decide to fast, focus on nutrient-dense meals at Iftar and Sahur—including fruits, vegetables, protein, whole grains, and plenty of fluids (calorie-free drinks are acceptable during non-fasting hours). Prioritize balanced hydration and rest to prevent fatigue. Remember, Islam permits breaking the fast if it poses a risk to you or your baby.

Be sure to speak with your healthcare provider before Ramadan. They can assess your specific risks, monitor blood sugar or weight, and suggest adjustments. As recommended by diabetes experts, pre-Ramadan counseling is key.[6] If you are high-risk, they may advise skipping the fast entirely to protect your pregnancy.

Final Thoughts: Faith, Health, and Balance

Fasting during Ramadan can be spiritually rewarding, but your health—and that of your baby—is the priority. Science shows it is generally safe in low-risk pregnancies with no major short-term harm, but caution is wise given the concerns regarding long-term risks for certain groups.[11] Ultimately, it is a personal choice supported by the exemptions of your faith. Prioritize open conversations with your doctor for an informed decision that honors both your beliefs and your well-being.

General Info: Some claims are derived from established nutritional principles where pregnancy-fasting studies are limited.

References

1. Glazier J, Hayes D, et al. 2018. https://doi.org/10.1186/s12884-018-2048-y
2. Tith R M, Bilodeau-Bertrand M, et al. 2019. https://doi.org/10.1093/jn/nxz126
3. Mahanani M R, Abderbwih E, et al. 2021. https://doi.org/10.3390/nu13124511
4. Oosterwijk V N L, Molenaar J, et al. 2021. https://doi.org/10.3390/nu13103450
5. Safari K, Piro T, Ahmad H. 2019. https://doi.org/10.1186/s12884-019-2275-x
6. Ibrahim M, Davies M, et al. 2020. https://doi.org/10.1136/bmjdrc-2020-001248
7. Ahmed S H, Chowdhury T, et al. 2020. https://doi.org/10.1007/s13300-020-00886-y
8. Ong A K W, Yee A L, et al. 2023. https://doi.org/10.1111/ajo.13706
9. Savitri A I, Amelia D, et al. 2018. https://doi.org/10.1017/jns.2017.70
10. AlMogbel T, Ross G, et al. 2021. https://doi.org/10.1007/s00592-021-01782-y
11. Chen Y, Loy S, Chen L. 2023. https://doi.org/10.3390/nu15030756