Fasting During Pregnancy – A Registered Dietitian’s Perspective

By Emily Mitchell MS, RD, CSSD, CDE, CLT

As a dietitian who specializes in optimization of maternal health from preconception through postpartum period, I emphasize “mindful” eating to all our patients. This approach stresses the importance of listening to your body and eating when you are hungry, as it’s nature and pregnancy’s way of teaching you how to nourish your body.

There are, however, many occasions when women may not be able to adopt this approach.  These episodes may be due to nausea and vomiting early in her pregnancy, a loss of or increased appetite as pregnancy progresses, social circumstances, or as prescribed by religion.

Working in Los Angeles requires knowledge of all religious practice and beliefs, especially when it involves food. A client may fast during Ramadan which involves a month of fasting during daylight, observing lent, or various Jewish holidays such as Yom Kippur.  There are many different religious opinions on who should not fast and the role of your doctor, our practice at the Center for Fetal Medicine and Women’s Ultrasound suggest discussing this with your doctor first and then your clergy.

Our doctors and I have worked together to answer the questions we hear from our patients during these times of fasting.

What are the usual nutritional demands in pregnancy?

When the pregnant woman is not fasting, she should strive to have:

  • Three calcium rich sources daily (yogurt, milk, cheese, green leafy vegetables, almonds)
  • Energy-rich food sources at each meal and snack (100% whole wheat products, starchy vegetables, fruits, milk/yogurt, beans/lentils, quinoa, barley, ancient grains)
  • 5-9 servings of vegetables and fruits (aim for a variety of colors)
  • lean protein at each meal and snack with healthy fats (fish 2x/week, eggs, beans/lentils, poultry, tofu, lean red meat, nuts, avocado, plant-based oils)

What are the potential risks of fasting in pregnancy?

Research results vary significantly on the safety of fasting. Some studies show no effect on the mother and baby, while others found that women who fast may have preterm labor, babies with lower birth weight or shorter stature. The most consistent transient finding in fetuses during a fast is decreased fetal breathing, which resolves once the mother eats.

Nutritionally-speaking the risk of dehydration is higher in pregnant women who observe fasting during warm weather and fasting for longer periods of time (>12 hours).  One study showed that women who had regular pre-dawn and fast-breaking meals during the month of Ramadan did not have alterations in the amount of amniotic fluid.

If a pregnant woman plans to fast, what can she do to prepare for it?

It is essential stay hydrated severals days before you plan to fast and increase your intake of high water content foods like fruits and vegetables. When breaking the fast, having some dried fruit (such as 2-4 dates) can help promote the rehydration process.

Who should avoid fasting?

Pregnant women with these conditions should be counseled not to fast:

  • Anemia
  • Abnormal blood pressure (low or high)
  • Diabetes (gestational or pre-gestational)
  • Active infection, such as gastroenteritis or urinary tract infection
  • Weakness or fatigue
  • Insufficient weight gain
  • Nausea/vomiting of pregnancy or hyperemesis gravidarum
  • Twin gestations in second and third trimester
  • History of preterm delivery or current preterm contractions
  • History of growth restriction
  • History of eating disorders

Can a woman fast if she is breastfeeding?

Fasting may impact a woman’s milk supply and decrease the critical food supply of an exclusively breastfed infant. Women who are exclusively breastfeeding may be exempt from some religious fasts.  

It is important to discuss your plan with your doctor and religious leader and of course HONOR and NOURISH your body.



Posted in: Heathy Diet

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