Benefits, harms, and costs
- 1.Prevention of folate-sensitive anomalies should be evidence-based, and the benefits of preventing anomalies should balance any risks of folic acid supplementation (high).
- 2.Birth defects related to folate deficiency account for 2%–3% of prenatal or neonatal major anomalies and 4%–5% of total structural malformations or developmental conditions identified after birth. Folate-sensitive birth defects include neural tube defects, certain congenital heart and urinary tract defects, oral facial clefts, and limb-reduction anomalies (high).
- 1.Any woman aged 12–45 years who can become pregnant should be advised by their health care provider to maintain a healthy, folate-rich diet and should undergo a brief periodic dietary review (strong, moderate).
- 2.Health care providers can consider promoting regular consumption of choline-rich foods (meat, egg yolk) during wellness visits (such as for birth control renewal, Pap testing, gynaecologic examination), whether or not the patient is contemplating pregnancy (strong, moderate).
- 3.Health care providers should advise all women aged 12–45 years considering or planning a pregnancy about the benefits of taking an oral daily multivitamin containing folic acid (0.4֪–1.0 mg) to optimize serum and red blood cell folate levels (strong, high).
- 4.Folic acid should be taken in a daily oral multivitamin that includes a 2.6-μg dose of vitamin B12 (strong, high).
- 5.Any woman aged 12–45 years who can become pregnant and has pre-conception obesity (body mass index >30.0 kg/m2) may require a more personal and focused assessment for folate supplementation to prevent fetal anomalies, such as a pre-conception fasting serum folate concentration assessment. If a woman with obesity has had a previous fetus or child with a folate-sensitive fetal anomaly other than a neural tube defect, she should take a folic acid supplement containing the recommended dosage for women at increased risk (4–5 mg) (conditional, low).
- 6.High-dosage folate supplementation (oral dosage of 4–5 mg/d) should be used only for women at high risk; women who can become pregnant and who have had a previous pregnancy affected by a neural tube defect, have had a neural tube defect themselves, or have a first-degree relative with a neural tube defect (strong, moderate).
- 7.High-dosage supplementation requires 2 separate periods of supplementation: from pre-conception to 12 weeks gestation (see below), and from 12 weeks gestation until completion of breastfeeding, when the folic acid supplementation dosage reverts to the low-dosage regimen (strong, high).
There are 2 options for supplementation in the first period:
- 1.Standard option: a total pre-conception oral daily dosage of 4 mg folic acid (1 oral multivitamin supplement that contains 1.0 mg of folic acid and 2.6 μg of vitamin B12, an iron supplement of 16–20 mg/d, and 3 1.0-mg folic acid tablets); (strong, high) or
- 2.Personalized option: requires the patient to first take an oral daily multivitamin containing folic acid (0.4֪–1.0 mg) and vitamin B12 within the first 4–6 weeks of a 3-month pre-conception period, then complete a blood test to determine her fasting serum folate level. A daily dosage of folic acid supplementation (from this pre-conception period until 12 weeks gestation) of 0.4–1.0 mg would be chosen if results were in the optimal range, and a daily dosage of more than 1.0 mg, if the results were sub-optimal (strong, moderate–high).
- 8.Moderate-dosage folate supplementation: Women who can become pregnant and have either an increased risk of having a fetus with an NTD or other folate-sensitive congenital anomaly or other medical-surgical conditions associated with a risk of folate deficiency require 2 separate periods of supplementation (strong, high).
- •From pre-conception to 12 weeks gestation, the supplementation dosage is 1.0 mg of folic acid daily (1 oral multivitamin supplement that contains 1.0 mg folic acid and 2.6 μg vitamin B12, and an iron supplement of 16–20 mg/d).
- •After 12 weeks gestation, the folic acid supplementation dosage reverts to the low-dosage regimen.
- 9.Low-dosage folate supplementation: Women who can become pregnant and are at low risk of having a fetus with an NTD or other folate-sensitive congenital anomaly should consume a pre-conception and first-trimester diet of folate-rich foods along with a daily oral multivitamin supplement that contains 0.4 mg (400 μg) of folic acid and 2.6 μg of vitamin B12, and an iron supplement of 16–20 mg daily for at least 2–3 months before conception, throughout the pregnancy, and for 4–6 weeks postpartum or as long as breastfeeding continues (strong, high).
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This document reflects emerging clinical and scientific advances as of the publication date and is subject to change. The information is not meant to dictate an exclusive course of treatment or procedure. Institutions are free to amend the recommendations. The SOGC suggests, however, that they adequately document any such amendments.
Informed consent: Patients have the right and responsibility to make informed decisions about their care in partnership with their health care provider. In order to facilitate informed choice, patients should be provided with information and support that is evidence-based, culturally appropriate, and personalized. The values, beliefs and individual needs of each patient in the context of their personal circumstances should be considered and the final decision about care and treatment options chosen by the patient should be respected.
Language and inclusivity: The SOGC recognize the importance of being fully inclusive and, when context is appropriate, gender-neutral language will be used. In other circumstances, we continue to use gendered language because of our mission to advance women’s health. The SOGC recognizes and respects the rights of all people for whom the information in this document may apply, including but not limited to transgender, non-binary, and intersex people. The SOGC encourages health care providers to engage in respectful conversation with their patients about their gender identity and preferred gender pronouns and to apply these guidelines in a way that is sensitive to each person’s needs.