Folic acid
Folic acid is used to reduce the risk of defects in the development of the spine and brain in the baby. There are two different doses, and your doctor decides which is appropriate for you.
Standard dose
400 micrograms a day is recommended for everyone planning a pregnancy. It is started before pregnancy and continued through the first 12 weeks of pregnancy.
High dose
If one of the following applies, 5 milligrams a day is needed and should be started at least 1–3 months before pregnancy:
- A history of a defect in the development of the spine or brain in yourself, your partner, a previous pregnancy or your family
- Excess weight (body mass index above 30)
- Previous obesity surgery
- Diabetes
- Epilepsy and the use of medicines for it
- Sickle cell anaemia or thalassaemia
A common mistake: in people with a history of recurrent miscarriage of unexplained cause — where the special situations above do not apply — high-dose folic acid is not routinely recommended.
Iodine
An iodine supplement of 150 micrograms a day is recommended, started 3 months before pregnancy. The total daily intake should not exceed 500 micrograms.
Vaccines
Reviewing vaccination status before pregnancy is critical, because some vaccines cannot be given during pregnancy.
Vaccines that cannot be given in pregnancy
- The measles-mumps-rubella and chickenpox vaccines contain live virus and cannot be given during pregnancy.
- Those who are not immune need to complete these vaccines before pregnancy and to avoid pregnancy for at least 1 month after vaccination.
Important information to set your mind at rest: having been given a live vaccine while unknowingly pregnant is not a reason to end the pregnancy.
Vaccines that can safely be given in pregnancy too
- The influenza and COVID-19 vaccines can safely be given before pregnancy or at any stage of pregnancy.
- The whooping cough vaccine should be repeated in every pregnancy.
Long-term conditions and medicines
When a pregnancy is planned, all the medicines being taken are reviewed; those that could harm the baby are changed for safe alternatives.
Epilepsy
The type and dose of medicine should be reviewed with a specialist. Some active substances carry a higher risk of developmental problems in the baby; taking several medicines is reduced to a minimum before pregnancy and, where possible, a single medicine is used.
An important warning: epilepsy medicines must never be stopped suddenly without consulting a doctor. Having a seizure can pose a greater risk than the medicine itself.
Thyroid disease
In people with an underactive thyroid, the dose of medicine is adjusted before pregnancy so as to bring the level to target.
Medicines that need to be changed as soon as a pregnancy is planned
- Some blood pressure and kidney medicines (ACE inhibitors and similar groups)
- Some medicines used in sickle cell anaemia
- Oral iron chelators used in thalassaemia — they should be stopped 3 months before
- Medicines for osteoporosis
These changes are made with your doctor, not on your own.
Weight
Excess weight
A body mass index above 30 increases the risk of miscarriage, pre-eclampsia, gestational diabetes, blood clots, stillbirth and developmental defects in the baby.
The good news is this: weight lost before pregnancy directly reduces the risk of pre-eclampsia, stillbirth and a large baby, and increases the chance of a normal birth after a previous caesarean.
Medicines that help with weight loss are not recommended during pregnancy. For this reason work on weight should be planned before pregnancy.
Being very underweight
A body mass index below 18.5 also increases the risk of miscarriage in the first three months and the likelihood of poor growth in the baby. A balanced weight matters in both directions.
Smoking and alcohol
- Smoking is the most important modifiable risk factor for placental insufficiency, premature birth and stillbirth. When a pregnancy is being planned it is strongly recommended that both partners stop — in the father's case to prevent damage to sperm DNA.
- Alcohol is a proven risk factor for pregnancy loss and for lasting mental and physical harm to the baby. It should be stopped completely when a pregnancy is being planned.
Frequently Asked Questions
When and how much folic acid should I take?
The standard recommendation is 400 micrograms a day; it is started before pregnancy and continued through the first 12 weeks of pregnancy. In some situations, however, 5 milligrams a day is needed and should be started at least 1–3 months before pregnancy. Your doctor decides which is appropriate for you.
Who needs high-dose folic acid?
Those with a history of a defect in the development of the spine or brain in themselves, their partner, a previous pregnancy or the family; those with excess weight (body mass index above 30), previous obesity surgery, diabetes, epilepsy and the use of medicines for it, sickle cell anaemia or thalassaemia.
I have had a miscarriage — should I take high-dose folic acid?
In recurrent miscarriage of unexplained cause — where the special situations above (diabetes, epilepsy and so on) do not apply — high-dose folic acid is not routinely recommended. This is a common mistake.
Which vaccines should I have before pregnancy?
The measles-mumps-rubella and chickenpox vaccines contain live virus and cannot be given during pregnancy. If you are not immune you need to complete these before pregnancy and to avoid pregnancy for at least 1 month after vaccination. The influenza and COVID-19 vaccines can safely be given before or during pregnancy; the whooping cough vaccine is repeated in every pregnancy.
I was vaccinated without knowing I was pregnant — what should I do?
First, know this: having been given a live vaccine while unknowingly pregnant is not a reason to end the pregnancy. Tell your doctor about it; your follow-up plan is then made accordingly.
Should I stop my epilepsy medicine?
Definitely do not stop it on your own. Epilepsy medicines must never be stopped suddenly without consulting a doctor — having a seizure can pose a greater risk than the medicine itself. The right course is for the type and dose of medicine to be reviewed with a specialist when a pregnancy is being planned.
If I need to lose weight, when should I do it?
Before pregnancy. Weight lost before pregnancy directly reduces the risk of pre-eclampsia, stillbirth and a large baby, and increases the chance of a normal birth after a previous caesarean. Medicines that help with weight loss are also not recommended during pregnancy — which is another reason the preparation needs to be done beforehand.
Is being underweight also a risk?
Yes. A body mass index below 18.5 increases the risk of miscarriage in the first three months and the likelihood of poor growth in the baby. A balanced weight matters in both directions.
Does my partner need to do anything too?
Yes, particularly about smoking. Smoking is the most important modifiable risk factor for placental insufficiency, premature birth and stillbirth, and it is recommended that both partners stop when a pregnancy is being planned — in the father's case to prevent damage to sperm DNA. Alcohol should also be stopped completely when a pregnancy is being planned.
Sources
- RCOG guidelines — the management of obesity, epilepsy, thyroid disease, sickle cell anaemia and thalassaemia in pregnancy; recommendations on reviewing medicines and on vaccination before pregnancy.
- ESHRE Guideline on Recurrent Pregnancy Loss (2022 update) — the place of high-dose folic acid in unexplained recurrent miscarriage.
- National and international recommendations on folic acid and iodine supplementation before pregnancy.
The information on this page is based on the national and international guidelines listed above. The page is reviewed whenever those guidelines are updated.
Practice and Contact Details
The information on this page is general. Please speak to your doctor about your own situation.
- DoctorOp. Dr. Murat Alpay — Specialist in Obstetrics and Gynaecology
- AddressOp. Dr. Murat Alpay Practice, Tekelioğlu Cd. No:51 B Kat:2, Filo Apt., 07160 Muratpaşa / Antalya
- Telephone0505 351 77 88
- HoursMonday – Saturday 09:00 – 18:00 · Closed on Sunday