GPs are sometimes consulted by women who state their intentions to "start a family" and ask for advice and a check-up. This provides a window of opportunity for health promotion, as it is thought that women are very motivated to alter unhealthy lifestyles at this time.
Preconceptual care is distinct from antenatal care.It should include:
- Informed choice, which helps women and men to understand health issues that may affect conception and pregnancy.
- Women and their partners being encouraged to prepare actively for pregnancy, and be as healthy as possible.
- Optimising management of chronic health problems.
- Identifying couples who are at increased risk of having babies with a genetic malformation. Provide them with sufficient knowledge to make informed decisions.
A large number of pregnancies are unplanned - approximately a quarter in one study in Southampton. This, and the haphazard seeking of pre-pregnancy advice by many patients, means that many opportunities for pre-pregnancy counselling are missed. By the first antenatal visit, organogenesis is well underway and interventions to avoid malformations may be too late. For example, folic acid supplementation before conception and during the first trimester prevents the majority of cases of neural tube defect (NTD).[3, 4]Similarly, control of glucose in women with diabetes both before pregnancy and in early pregnancy helps to reduce the incidence of miscarriage, congenital malformation, stillbirth and neonatal death, so targeted care needs to occur before and in early pregnancy.[5, 6]Toxins such as alcohol can cause damage from the very early stages.
Efforts need to be made to offer preconceptual care opportunistically as part of other consultations - eg, contraception, diabetes or epilepsy reviews. Any couple being referred for infertility assessment should have had a full pre-conception assessment prior to further investigation or treatment. School-based programmes, in the context of children's reproductive and sex education, might offer better public health coverage.
Pre-conception counselling is also relevant to men. Their lifestyle and health may also affect pregnancy outcome.
Each woman requires individual assessment.
Establish the following in order to offer appropriate advice:
- Timing of planned pregnancy.
- Folic acid.
- Smear history.
- Smoking history.
- Alcohol intake.
- Weight (whether the patient is overweight or obese).
- Medication, including over-the-counter or herbal medication. Establish whether there is a history of illicit drugs.
- Risks of exposure to hazardous substances or radiation.
- Rubella immune status.
- History of chickenpox or shingles.
- Risk of hepatitis B.
- Risk of human immunodeficiency virus (HIV) infection.
- History of miscarriage.
- Risk or concern regarding chromosomal abnormalities or inherited genetic disorders.
- Chronic health problems. There is specific advice available for management of women with:
- Diabetes mellitus
- Thyroid disease
- Renal disease
- Sickle cell disease
- Rheumatoid arthritis
- Previous thromboembolism
- Bipolar disorder
Advice for all women
Timing of pregnancy
- In couples having regular sexual intercourse every two or three days, and not using contraception, 84% will become pregnant within a year, and 92% within two years. The rest may take longer to conceive and some may need help or intervention.
- Following use of the contraceptive injection, normal fertility may take up to a year to re-establish.
Supplementation with folic acid is one of the most significant preventative interventions available in the preconceptual/antenatal period:
- All women should take at least 400 micrograms/day whilst trying to become pregnant and for at least the first three months of pregnancy to reduce the risk of NTDs.
- Women at high risk of NTD should take a higher dose of 5 mg/day until 12 weeks of pregnancy. High risk is defined as:
- Where either partner has an NTD or has already had a pregnancy affected by NTD.
- Family history of NTD.
- Anti-epileptic medication.
- Coeliac disease.
- Diabetes (type 1 or 2).
- Thalassaemia trait (5 mg daily until birth of the baby).
- Haemolytic anaemia, particularly thalassaemia or sickle cell anaemia (5-10 mg until birth of the baby).
- Women with a BMI >30 kg/m2.
- Diet alone (eg, green vegetables, fortified cereals) does not reliably supply adequate folic acid.
- The Southampton study found that only 2.9% of women complied fully with pre-pregnancy advice regarding folic acid and alcohol.
- Identify women who are due or nearly due a cervical smear and encourage women to have their screen before becoming pregnant.
- Smears are not routinely taken during pregnancy, as pregnancy-related inflammatory changes make them difficult to interpret.
- Many treatments cannot be carried out during pregnancy should an abnormality be detected.
- Smoking in pregnancy is associated with a large number of adverse effects including:
- Intrauterine growth restriction
- Miscarriage and stillbirth
- Premature delivery
- Placental problems
- Also, ask regarding other smokers in the household, since smoking around a baby increases risk of sudden infant death and other respiratory diseases.
- Give appropriate health education regarding the effect of smoking on pregnancy and more broadly. Offer referral to a smoking cessation service.
- There is little information on the use of nicotine replacement therapy (NRT) in pregnancy but smoking gives a greater dose of nicotine and also exposes mother and fetus to other toxins. It is likely to be safer than smoking in mothers for whom non-pharmacological interventions have failed but risks and benefits should be fully discussed. NRT patches should be removed at night in pregnancy.
- Advise that bupropion and varenicline should NOT be used in pregnancy.
- Advise of the benefits of stopping smoking before pregnancy, so these concerns are not an issue.
- High levels of alcohol consumption during pregnancy may result in fetal alcohol syndrome (FAS). There are various components including growth restriction, intellectual impairment, facial anomalies and behavioural problems.
- Advise women planning a pregnancy to avoid alcohol completely during the first trimester, as there appears to be a small increased risk of miscarriage associated with drinking alcohol.
- National Institute for Health and Care Excellence (NICE) guidelines state there is no clear safe level of consumption but if women choose to drink alcohol during pregnancy, particularly after the first trimester, they should be advised to drink no more than 1-2 units, no more than twice a week. At this low level there is no evidence of harm to the unborn baby. Guidelines further advise that women should avoid becoming drunk and binge drinking.
- However proposed guidelines from the Department of Health in January 2016 advise the safest advice to give women is that they should avoid drinking alcohol altogether throughout pregnancy.
- Where a woman is unable to reduce her alcohol consumption with support in primary care, offer specialist referral.
- Advise women who are overweight (BMI 25-29.9) or obese (BMI ≥30) to lose weight before becoming pregnant. A healthy weight reduces the risk of NTD, preterm delivery, gestational diabetes, caesarean delivery, hypertension and thromboembolic disease and is also more likely to promote conception. Similarly, women who are underweight may find getting pregnant difficult and be at risk of more pregnancy-related complications.
- Whilst it is often impractical to achieve ideal body weight, women should be advised as to their increased risk of adverse pregnancy outcomes associated with their weight, particularly at BMIs >40. Consultation with a dietician may be helpful.
- It is good practice to minimise exposure to all drugs, including those bought over the counter.
- Consider all regular medication, consider safety in pregnancy and change where necessary and possible.
- There are little data on herbal preparations in pregnancy and they should also be avoided.
- Advise not to exceed 10,000 IU of vitamin A from vitamin supplements either prior to or during pregnancy, as vitamin A is a potent teratogen.
Illicit drug use
- Advise to stop using illicit drugs if a pregnancy is desired.
- Offer referral where the woman is planning a pregnancy and is unable to stop using without support. A multidisciplinary approach is essential. Most localities will have a clearly defined drug dependency service with a readily accessible entry point.
- Encourage the use of reliable contraception whilst drug use continues.
- Where injecting drugs, or with a past history of such behaviour, offer hepatitis B and C and HIV testing.
- Cocaine use in pregnancy is particularly serious and has been associated with spontaneous abortion, placental abruption, premature birth, low birth weight and sudden infant death syndrome. There is conflicting evidence regarding fetal abnormalities.
- Opiate use is associated with increased incidence of intrauterine growth restriction and preterm delivery. This contributes to an increased rate of low birth weight and perinatal mortality. Women addicted to heroin who wish to become pregnant should be urged to enter a detoxification programme before conception and if not then at least stabilised on methadone.
- The direct effects of cannabis on the fetus are uncertain but may be harmful. Its use associated with smoking is known to be harmful and women should be counselled against smoking cannabis before and during pregnancy.
Risks from the environment
- Consider potential hazards at home (eg, pets or farm animals, domestic chemicals) or at work.
- Women exposed to sheep should be warned of the risk of Chlamydophila abortus at lambing time, which can cause miscarriage or stillbirth.
- Advise to wash hands after gardening and to avoid cleaning cat litter trays during pregnancy to avoid toxoplasmosis.
- Advise a woman planning pregnancy to read product warnings before using chemicals.
- Advise a woman who is planning pregnancy and is concerned about work exposure to hazardous substances, infections or radiation, to disclose her intention of becoming pregnant to her employer, if possible, so that a risk assessment may be carried out in advance of pregnancy.
- Where she does not feel able to disclose her intention of becoming pregnant to her employer, she can obtain information about the risk of exposure to specific substances by contacting the Health and Safety Executive.
In healthy women on a normal diet, advice on eating five portions of fruit and vegetables per day and consuming dairy products to raise stores of vitamins, iron and calcium is reasonable. It is advised that certain foods be avoided in pregnancy, or reduced, so if a woman is likely to become pregnant imminently, it is sensible to forewarn her of these precautions.
- Because of the dangers of toxoplasmosis, salmonella and listeriosis, women should avoid:
- Uncooked meat, fish and eggs.
- Pâté, including vegetable pâté.
- Unpasteurised milk.
- Raw shellfish.
- Unripened soft cheeses, such as Brie, Camembert or blue-veined cheese.
- Unwashed fruit and vegetables.
- Fish containing high levels of mercury should be avoided, such as shark, swordfish or marlin. Tuna should be limited to no more than two medium-sized cans or one fresh tuna steak per week.
- Liver and liver products should be avoided due to the potential vitamin A content.
- Vegetarians, and especially vegans, are at risk of various nutritional deficiencies and may need to be referred to a dietician.
- Vitamin D deficiency causes impaired fetal growth. All women should be informed about the importance of maintaining adequate vitamin D stores during pregnancy and breast-feeding. Women at particular risk of deficiency include:
- Women of South Asian, African, Caribbean or Middle Eastern family origin.
- Women with limited exposure to sunlight.
- Women who do not eat oily fish, eggs, meat or fortified margarine or cereals.
- Women with a pre-pregnancy BMI >30.
- Caffeine during pregnancy may cause intrauterine growth restriction. One cohort study found an odds ratio of 1.2 for 100-199 mg of caffeine/day (1-2 cups of coffee, 2-4 cups of tea) and 1.6 for >300 mg caffeine/day (more than 3 cups of coffee or 6 cups of tea). A sensible approach would be to reduce caffeine consumption prior to pregnancy in heavy users.NICE guidelines recommend limiting caffeine intake to 300mg per day during pregnancy.This is the equivalent of 3 mugs of instant coffee, 2 mugs of filter coffee or 4 cups of tea.
- Women should be cautioned, however, against substituting caffeinated drinks with herbal preparations and teas, as their use and safety in pregnancy have not been studied.
- Women who exercise regularly should be advised to continue to do so.
- Those who are inactive should start a gentle programme of regular exercise.
- Saunas and hot tubs should be avoided because of possible risk of hyperthermia to the fetus, which is particularly risky in very early pregnancy.[18, 19]
- Women should be advised of the potential dangers of certain activities during pregnancy - eg, contact or high-impact sports, vigorous racquet sports and scuba diving.
See separate Rubella and Pregnancy article.
- Primary rubella infection can be disastrous for the fetus. Defects include intellectual impairment, cataract, deafness, cardiac abnormalities and intrauterine growth restriction.
- Infection in the first 8-10 weeks of pregnancy results in damage in up to 90% of infants.Defects are rare after 16 weeks of gestation. Whilst women are routinely screened during pregnancy for rubella, this cannot provide protection for the current pregnancy, as immunisation must wait until immediately postpartum.
- With the downturn in rates of measles, mumps and rubella (MMR) vaccination and increasing numbers of births to women born outside the UK who may or may not have been offered rubella vaccination, increased vigilance is required.
- Test for immunity or vaccinate anyway in women without proof of vaccination. Advise the woman not to get pregnant for a month after vaccination, although large numbers of studies have failed to show adverse effects of vaccination in early pregnancy.
Those at risk of viral hepatitis (eg, multiple sexual partners, visitors to endemic areas, healthcare workers, intravenous drug users) should be screened and vaccinated against hepatitis B if not infected.
- In the first 20 weeks of pregnancy, varicella in the mother may cause congenital fetal varicella syndrome. This may cause limb hypoplasia, microcephaly, cataracts, growth restriction and skin scarring. It has a low incidence (less than 1% in the first 12 weeks) but the mortality rate is high. There have been very few case reports of fetal damage between 20 to 28 weeks of gestation.
- Test women planning pregnancy for varicella who do not have a positive history of chickenpox or shingles.
- The Department of Health recommends vaccinating the following people if seronegative:
- Healthcare workers with direct patient contact.
- Healthy, susceptible, close household contacts of immunocompromised patients.
NB: varicella vaccines must not be given to pregnant women.
- The Royal College of Obstetricians and Gynaecologists advises that women over the age of 35 should be counselled about the increased risks. The current trend is for women to have babies later. Women should be supported in their choices, but should be aware that outcomes change with age. Older age is associated with increasing difficulty in conceiving, increasing risk of miscarriage, twins, fibroids, hypertension, gestational diabetes, labour problems and perinatal mortality with increasing maternal age.
- It is important to say that most pregnancies are uneventful and have a good outcome.
- NICE guidelines recommend informing women over the age of 30 of the increasing risk of Down's syndrome (trisomy 21) with maternal age. The risk of fetal chromosomal abnormalities, particularly Down's syndrome, increases sharply with maternal age (1 in 1,500 risk at 20 years, 1 in 800 at 30 years, 1 in 270 at 35 years, 1 in 100 at 40 years, 1 in 50 or more at over 45 years).
Advice for women with a history of miscarriage
- Reassure women that there is a good chance of a subsequent successful pregnancy.
- Refer women with three or more consecutive miscarriages to a gynaecologist for investigation.
Advice for women with a history of chronic diseases
- Many chronic diseases and their treatments may have implications for fetal health and development. Similarly, pregnancy and labour may worsen pre-existing maternal conditions.
- Women should have the opportunity to discuss these risks in order to make balanced reproductive choices and to optimise their health, disease control and medication prior to conception.
- Within primary care, encourage women to continue to use contraception and their regular medication until they have had a full review with their specialised team, as well as other routine preconceptual care.
See separate Management of Adult Asthma article.
- A high level of control is essential during pregnancy and patients should be advised to use their peak flow meters and inhalers with extra care, especially the prophylactic steroids. There is little need for modification of treatment in pregnancy, and the risk of uncontrolled asthma outweighs any risk from medication.
- Steroids should be used as needed in the usual way and not withheld due to pregnancy.
- Women with severe or poorly controlled asthma may need to be assessed by a chest physician.
See separate Diabetes in Pregnancy article.
- From adolescence onwards, advise women with diabetes about the risks of unplanned pregnancy, the effects of pregnancy on diabetes and vice versa.
- Explain to women with diabetes who are planning to become pregnant that good blood glucose control before conception and throughout pregnancy will reduce the risk of miscarriage, congenital malformation, stillbirth and neonatal death.
- Refer all women with diabetes, who are planning pregnancy, to a diabetic clinic or a specialised pre-conception diabetes clinic where available. Advise them they will need extra monitoring and appointments.
- Structured educational programmes should be offered where women have not previously attended one.
- Provide advice on diet, exercise and weight loss (if BMI is >27).
- Patients need to ensure very tight control of their blood glucose during pregnancy, including from pre-conception. Good glycaemic control reduces but does not eliminate the risks of miscarriage, congenital malformations, stillbirth and neonatal death.
- Blood glucose targets, monitoring and control should be discussed prior to pregnancy. HbA1c should be kept below 48 mmol/mol to reduce the risk of congenital malformation. Women with HbA1c of above 86 mmol/mol should avoid pregnancy until better control has been established. HbA1c should be measured monthly preconceptually. Individualised targets for self-monitoring of blood glucose should be agreed, taking into account risk of hypoglycaemia (the risks of hypoglycaemia and hypoglycaemia unawareness are greater in pregnancy). The usual targets are a fasting glucose between 5-7 mmol/L on waking and 4-7 mmol/L before meals the rest of the day.
- Metformin can sometimes be used as an adjunct or alternative to insulin in those with type 2 diabetes but other oral hypoglycaemics should be discontinued prior to pregnancy. Many with type 2 diabetes will be converted to insulin during this period..
- Aspart and lispro (rapid-acting insulin analogues) are safe during pregnancy, whilst isophane insulin is the preferred choice for long-acting insulin.
- Review concurrent medication and stop angiotensin-converting enzyme (ACE) inhibitors, angiotensin-II receptor antagonists (AIIRAs, commonly known as angiotensin receptor blockers (ARBs)), and statins.
- Check for retinal and renal complications. Retinal screening should be done unless it has been done in the previous six months. Refer to nephrology where eGFR <45 ml/minute, creatinine is abnormal or the urinary albumin:creatinine ratio >30 mg/mmol.
- Check for co-existing thyroid disease in those with type 1 diabetes (TSH, free T4 and thyroid peroxidase antibodies).
- Treat as high risk for NTD with a dose of 5 mg folic acid pre-conception and up to 12 weeks.
See separate Hypertension in Pregnancy article.
- Hypertension increases the risk of pre-eclampsia during pregnancy. It also increases the risk of placental abruption and neonatal morbidity and mortality.
- Refer to a cardiologist for advice regarding medication. ACE inhibitors and AIIRAs are contra-indicated in pregnancy, so ideally should be changed prior to pregnancy. If the woman becomes pregnant whilst awaiting a specialist opinion, they should be stopped immediately. If necessary, substitute with an alternative agent suitable for use during pregnancy. Labetalol is usually the first-line treatment used.
- Chlorothiazide also presents a risk of congenital abnormality and neonatal complications and should be changed to an alternative agent.
- Drugs of choice are methyldopa, beta-blockers (labetalol, propranolol, metoprolol) and nifedipine.
- In uncomplicated hypertension, target blood pressure will be below 150/100 mm Hg.
- Women with thalassaemia should be referred to a haematologist for advice and those with thalassaemia trait discussed with or referred to a haematologist. They should take 5 mg of folic acid per day from pre-conception through to delivery.
- Women with thalassaemia are at risk of anaemia, pre-eclampsia, and complications during labour.
- Seek advice from a haematologist for women who are carriers for thalassaemia and have an unusual variant or need further investigation. Ensure the partner has been tested. These women should also receive 5 mg of folic acid.
- All women with sickle cell disease should be referred to a haematologist, as they are at risk of sickle cell crises and complications in pregnancy. They should be on 5 mg folic acid for life. Women who are carriers should be treated as in a normal pregnancy and should receive the normal 0.4 mg dose of folic acid.
See separate Congenital Heart Disease in Adults article.
- All women with congenital or acquired heart disease should discuss future pregnancies with a cardiologist. Advise women to continue contraception until this discussion has taken place.
- Statins are contra-indicated in pregnancy and should be stopped prior to conception.
- Most anti-epileptic drugs (AEDs) are teratogenic, although the risk is reduced if used as monotherapy.
- Referral to a specialist centre is required so that control can be maintained whilst minimising the risk to the fetus. Advise women to continue using contraception until discussion with a specialist has taken place.
- Sodium valproate is associated with a particularly high risk.
- Women on AEDs should use 5 mg of folic acid per day from before conception until 12 weeks of pregnancy to reduce the risk of NTDs.
See separate Thyroid Disease in Pregnancy article.
- Check TFTs if not done in the previous six months.
- Those with subclinical hypothyroidism, should commence treatment and be referred to an endocrinologist if contemplating pregnancy.
- Those on treatment for hypothyroidism, should be reviewed to ensure optimum control. The requirement for thyroid replacement therapy increases in pregnancy.
- Hyperthyroid individuals should be reviewed by the specialist team and may wish to consider treatment with radioactive iodine or surgery prior to pregnancy. Radioactive iodine is contra-indicated in pregnancy and breast-feeding.
- Advise women that frequent monitoring will be required during pregnancy.
- Women with renal impairment who are planning pregnancy should be referred to a specialist for advice. Advise women to continue using contraception until they have discussed pregnancy with the specialist.
- Renal disease in pregnancy may be associated with intrauterine growth restriction, prematurity and deterioration in maternal renal function.
- Most women with severe renal disease are infertile and if they do conceive, the risks are high.
- Women with progressive renal disease may be advised to complete pregnancies while renal function remains relatively good.
- Women with rheumatoid arthritis considering pregnancy should be referred to a rheumatologist to review their medication which may be teratogenic.
- Advise women to continue using contraception whilst taking teratogenic medication, particularly disease-modifying antirheumatic medication.
Venous thromboembolism (VTE)
- Screen women with a personal or immediate family history of VTE for thrombophilia.
- Women planning pregnancy who have a history of deep vein thrombosis (DVT) or pulmonary embolism (PE) or an abnormal thrombophilia screen should be referred to a specialist for advice. Thromboprophylaxis may be needed.
- Warfarin is teratogenic and therefore contra-indicated in pregnancy and must be stopped or replaced by heparin. New anticoagulants such as dabigatran, apixaban and rivaroxaban also do not appear to be safe in pregnancy and should be replaced.
See separate Antenatal Mental Health Problems article.
- The risk of stopping treatment has to be weighed on an individual basis against the possible risk of the medication. It is helpful to have these discussions pre-conception.
- Ideally, medication should be stopped prior to pregnancy but if this is not possible, the antidepressants with the lowest risk should be used.
- Seek specialist advice in women with severe depression who are planning pregnancy.
- For mild depression, consider gradual withdrawal of antidepressants and, if need be, starting psychological therapy or self-help measures. A switch to psychological therapy may also be a possibility for women who have been treated for moderate or severe depressive episodes.
- Inevitably evidence is limited on the safety of antidepressants in pregnancy. No risk has been demonstrated with tricyclic antidepressants (TCAs). Limited studies on the selective serotonin reuptake inhibitors (SSRIs) suggest possible risks of malformations with their use in the first trimester, and a possible withdrawal effect and (rarely) pulmonary hypertension in the newborn when used later in pregnancy. Fluvoxamine appears to be safer, whilst more ill effects have been reported for paroxetine. Evidence remains contradictory and, although ill effects appear to be rare, it is wise to avoid unless necessary. Mirtazapine and venlafaxine have not been found to be associated with congenital malformations. There are potential risks of neonatal withdrawal, however. Other antidepressants should be avoided because of still more limited available evidence.
- The UK teratology information service (UKTIS) is unable to recommend the safest antidepressant in pregnancy, and NICE Clinical Knowledge Summaries (CKS) also declines to do so.
- Sudden withdrawal of an antidepressant in a woman with a history of severe depression may cause more harm than the potential risk of the medication.
- All women with a history of bipolar disorder who are considering pregnancy should be referred to a specialist for assessment and advice about medication. Advise women to continue contraception until this has occurred.
- Medication may adversely affect pregnancy outcome and need changing. Lithium, valproate, lamotrigine and carbamazepine would normally be stopped. Alternative medication, such as an antipsychotic, may be considered in secondary care.
- Some of the medication used may affect fertility adversely.
- Women with bipolar disorder have a 50% risk of puerperal psychosis and therefore need to be monitored by and under the care of specialised services.
All women with schizophrenia planning pregnancy should be referred to a psychiatrist to weigh up risks of medication against risk of relapse. Advise women to continue with contraception until this discussion has taken place. Medication may need to be changed prior to pregnancy, and dose changes may be needed in pregnancy.
Advice for women who require genetic screening
- Identify women at high risk of haemoglobinopathy with use of the history and family of origin questionnaire.
- Arrange blood count and electrophoresis for high-risk women as appropriate.
- Consider referral for genetic screening and advice for couples planning pregnancy who have personal or family history of inherited genetic disorders, or who have had a previous pregnancy affected. Relevant conditions include:
- Huntington's disease.
- Tuberous sclerosis.
- Marfan's syndrome.
- Adult polycystic disease.
- Cystic fibrosis.
- Tay-Sachs disease.
- Gaucher's disease.
- Friedreich's ataxia.
- Congenital adrenal hyperplasia.
- Spinal muscular atrophy.
- Duchenne muscular dystrophy.
- Fragile X syndrome.
- Haemophilias A and B.
- Glucose-6-phosphate dehydrogenase deficiency.
- Advise women at risk of an inherited genetic disorder for which they may request termination, to present early in pregnancy for testing to be arranged where relevant.
Did you find this information useful?
- Feldman HS, Jones KL, Lindsay S, et al; Prenatal alcohol exposure patterns and alcohol-related birth defects and growth deficiencies: a prospective study. Alcohol Clin Exp Res. 2012 Apr 36(4):670-6. doi:
- Pre-conception - advice and management; NICE CKS, June 2012 (UK access only )
- Inskip HM, Crozier SR, Godfrey KM, et al; Women's compliance with nutrition and lifestyle recommendations before pregnancy: general population cohort study. BMJ. 2009 Feb 12 338:b481. doi: 10.1136/bmj.b481.
- De-Regil LM, Pena-Rosas JP, Fernandez-Gaxiola AC, et al; Effects and safety of periconceptional oral folate supplementation for preventing birth defects. Cochrane Database Syst Rev. 2015 Dec 14 12:CD007950. doi: 10.1002/14651858.CD007950.pub3.
- Cawley S, Mullaney L, McKeating A, et al; A review of European guidelines on periconceptional folic acid supplementation. Eur J Clin Nutr. 2015 Sep 9. doi: 10.1038/ejcn.2015.131.
- Diabetes in pregnancy: management of diabetes and its complications from preconception to the postnatal period; NICE Clinical Guideline (February 2015)
- Gough A, McCance D, Alderdice F, et al; Preconception counselling resource for women with diabetes. BMJ Qual Improv Rep. 2015 Oct 12 4(1). pii: u209621.w3984. doi: 10.1136/bmjquality.u209621.w3984. eCollection 2015.
- Bille C, Andersen AM; Preconception care. BMJ. 2009 Feb 12 338:b22. doi: 10.1136/bmj.b22.
- Frey KA, Navarro SM, Kotelchuck M, et al; The clinical content of preconception care: preconception care for men. Am J Obstet Gynecol. 2008 Dec 199(6 Suppl 2):S389-95. doi: 10.1016/j.ajog.2008.10.024.
- Guidelines for the management of sexual and reproductive health of people living with HIV infection; British HIV Association (2008)
- Antenatal care for uncomplicated pregnancies; NICE Clinical Guideline (March 2008, updated 2017)
- UK Chief Medical Officers' Alcohol Guidelines Review, Summary of the Proposed new guidelines; Dept of Health, January 2016
- Dietary interventions and physical activity interventions for weight management before, during and after pregnancy; NICE Public Health Guideline (July 2010)
- Chlamydophila abortus; Public Health England
- Health and Safety Executive
- Healthy Start; GOV.UK
- No authors listed; Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study. BMJ. 2008 Nov 3 337:a2332. doi: 10.1136/bmj.a2332.
- Exercise in Pregnancy; Royal College of Obstetricians and Gynaecologists (2006)
- Chambers CD; Risks of hyperthermia associated with hot tub or spa use by pregnant women. Birth Defects Res A Clin Mol Teratol. 2006 Aug 76(8):569-73.
- Duong HT, Shahrukh Hashmi S, Ramadhani T, et al; Maternal use of hot tub and major structural birth defects. Birth Defects Res A Clin Mol Teratol. 2011 Sep 91(9):836-41. doi: 10.1002/bdra.20831. Epub 2011 Jun 6.
- Rubella: the green book, chapter 28; Public Health England (April 2013)
- Varicella: the Green Book, Chapter 34; Public Health England (April 2013)
- RCOG Statement on later maternal age; Royal College of Obstetricians and Gynaecologists, 15 June 2009
- Miscarriage; NICE CKS, July 2013 (UK access only)
- Hypertension in pregnancy; NICE Quality Standard, July 2013
- Hypertension in pregnancy; NICE CKS, April 2015 (UK access only)
- Epilepsies: diagnosis and management; NICE Clinical Guideline (January 2012)
- Antenatal and postnatal mental health: clinical management and service guidance; NICE Clinical Guideline (December 2014)
- Family Origin Questionnaire; NHS February 2014