What are the guidelines for fasting in women?

Guidelines for Fasting in Women

For women, fasting guidelines recommend clear liquids up to 2 hours before procedures and solid foods should be avoided for at least 6-8 hours before elective procedures, with specific considerations for pregnant and laboring women. 1

General Fasting Guidelines for Women Undergoing Procedures

Clear Liquids

• Clear liquids may be consumed up to 2 hours before elective procedures requiring anesthesia 1
• Examples of clear liquids include water, fruit juices without pulp, carbonated beverages, clear tea, black coffee, and sports drinks 1
• The volume of liquid is less important than the absence of particulate matter 1

Breast Milk

• Fasting from breast milk should be maintained for at least 4 hours before elective procedures 1

Infant Formula

• Fasting from infant formula should be maintained for at least 6 hours before elective procedures 1

Non-human Milk and Solids

• Fasting from non-human milk should be maintained for at least 6 hours before elective procedures 1
• Light meals (e.g., toast and clear liquids) require fasting for at least 6 hours before elective procedures 1
• Meals containing fried or fatty foods or meat may require extended fasting periods (8 hours or more) 1
• Both the amount and type of food ingested must be considered when determining appropriate fasting periods 1

Special Considerations for Pregnant Women

Women in Labor

• Modest amounts of clear liquids may be allowed for uncomplicated laboring patients 1
• Solid foods should be avoided in laboring patients 1
• Women with additional risk factors for aspiration (e.g., morbid obesity, diabetes, difficult airway) may require further restrictions of oral intake 1
• Women at increased risk for operative delivery (e.g., non-reassuring fetal heart rate pattern) may need case-by-case restrictions 1

Women Undergoing Cesarean Delivery

• For elective cesarean delivery, clear liquids may be consumed up to 2 hours before anesthesia induction 1
• For elective cesarean delivery, a fasting period of 6-8 hours for solids is recommended, depending on the type of food ingested 1
• After cesarean delivery, a regular diet can be resumed within 2 hours postoperatively 1

Pharmacologic Interventions

Not Routinely Recommended

• Gastrointestinal stimulants (e.g., metoclopramide) are not routinely recommended for patients with no increased risk for pulmonary aspiration 1
• Antiemetics (e.g., ondansetron, droperidol) are not routinely recommended for pulmonary aspiration risk reduction 1
• Anticholinergics (e.g., atropine, glycopyrrolate) are not recommended to decrease pulmonary aspiration risks 1

For High-Risk Patients

• Non-particulate antacids (e.g., sodium citrate, sodium bicarbonate) may be administered before operative procedures in obstetric patients to reduce complications 1
• H2 receptor antagonists may be effective in decreasing gastric acidity in obstetric patients 1
• Metoclopramide may be effective in reducing peripartum nausea and vomiting 1

Intermittent Fasting for Women's Health

While not part of procedural fasting guidelines, intermittent fasting has gained popularity for weight management and health benefits:

• Intermittent fasting approaches include alternate-day fasting, 5:2 diet (two fast days and five regular eating days per week), and time-restricted eating 2, 3
• These approaches have shown potential benefits for weight loss (approximately 3-7% reduction in body weight) and improvements in metabolic parameters 4, 5
• For women specifically, therapeutic fasting has shown potential benefits for reproductive health, mental health, and prevention of conditions common in middle-aged and elderly women 6
• Compliance with 5:2 intermittent fasting shows women may consume higher calories on non-fasting days following a fast day, suggesting potential compensation effects 5

Common Pitfalls and Caveats

• The timing of delivery in laboring patients is uncertain, making compliance with predetermined fasting periods before non-elective procedures challenging 1
• Fasting guidelines apply to healthy patients undergoing elective procedures and may need modification for patients with comorbidities 1
• Following fasting guidelines does not guarantee complete gastric emptying 1
• Extended fasting beyond recommendations (>8 hours) may be associated with hypoglycemia, particularly in children 1
• For intermittent fasting regimens, compliance rates may be lower than reported in controlled studies, potentially affecting long-term sustainability 5