oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
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.
- 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.
- 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 a recent 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 reduces the risk of a neural tube defect (NTD) by 50-70%. Similarly, control of glucose in women with diabetes appears to be most critical during the first 8-10 weeks of pregnancy in terms of preventing birth defects, so targeted care needs to occur before and early in pregnancy. 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 (overweight or obese?).
- Medication, including over-the-counter or herbal medication. History of illicit drugs?
- Risks of exposure to hazardous substances or radiation.
- Rubella immune status.
- History of chickenpox or shingles.
- Risk of hepatitis B.
- 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 2 or 3 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.
- The optimum biological age for pregnancy is between 20-35 years of age.
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 neural tube defects (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% 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 in pregnancy including:
- 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.
- Bupropion should NOT be prescribed 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 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.
- 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.
- Advise to avoid becoming drunk and binge drinking.
- 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 dietitian may be helpful.
- It is good practice to minimise exposure to all drugs, including those bought over the counter.
- 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.
- Because of the dangers of toxoplasmosis and listeriosis, women should avoid:
- Uncooked meat, fish and eggs
- Fish with high levels of mercury
- Unpasteurised milk
- Unripened soft cheeses, such as Brie, Camembert or blue-veined cheese
- Unwashed fruit and vegetables
- Vegetarians, and especially vegans, are at risk of various nutritional deficiencies and may need to be referred to a dietitian.
- 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 fetal 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.
- 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.
- 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 article Rubella and Pregnancy
- 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, IV 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.
Advice for older women
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, increased risk of adverse outcomes and complications of pregnancy. 
- It is important to say that most pregnancies are uneventful and have a good outcome.
- The risk of fetal chromosomal abnormalities, particularly Down's syndrome (trisomy 21), increases sharply with maternal age (1 in 1,500 risk at 20 years, 1 in 270 at 35 years, 1 in 100 at 40 years, 1 in 50 or more at over 45 years).
- There is also an increased risk of infertility, miscarriage, twins, fibroids, hypertension, gestational diabetes, labour problems, and perinatal mortality with increasing maternal age.
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 article Management of Adult Asthma.
- 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 article Diabetes in Pregnancy.
- From adolescence onwards, advise women about the risks of unplanned pregnancy, the effects of pregnancy on diabetes and vice versa.
- Refer all women with diabetes, who are planning pregnancy, to a diabetic clinic or a specialised pre-conception diabetes clinic where available. Both the diabetic and obstetric team need to be involved in preconceptual counselling.
- Structured educational programmes should be offered where women have not previously attended one.
- Provide advice on diet, exercise and weight loss (if BMI >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.
- Check for retinal and renal complications. Refer to nephrology where eGFR <45 ml/minute.
- Blood glucose targets, monitoring and control should be discussed prior to pregnancy. Where safe, HbA1c should be kept below 6.1%. Women with HbA1c of above 10% should avoid pregnancy. 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).
- 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 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 article Hypertension in Pregnancy.
- Hypertension increases the risk of pre-eclampsia during pregnancy. It also increases the risk of placental abruption and neonatal morbidity and mortality.
- ACE inhibitors and AIIRAs are contra-indicated and should be substituted with an alternative agent suitable for use during pregnancy. Women who become pregnant whilst taking ACE inhibitors should be referred promptly to a specialist for medication switching. They should be advised not to stop their ACE inhibitor without a controlled switch because of the risk to mother and fetus of uncontrolled hypertension. ACE inhibitors taken in the first trimester present only a small risk of fetal abnormalities.
- 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 hydralazine.
- Refer to a cardiologist for advice.
- 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.
- 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.
See separate article Congenital Heart Disease in Adults.
- All women with congenital or acquired heart disease should discuss future pregnancies with a cardiologist.
- Statins are contra-indicated in pregnancy and should be stopped prior to conception.
See separate article Epilepsy and Pregnancy.
- 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.
- 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 article Thyroid Disease in Pregnancy.
- 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.
- Women with renal impairment who are planning pregnancy should be referred to a specialist for advice.
- 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.
Venous thromboembolism (VTE)
- Screen women with a 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.
- Warfarin is teratogenic and therefore contra-indicated in pregnancy and must be stopped or replaced by heparin. New anticoagulants such as dabigatran and rivaroxaban also do not appear to be safe in pregnancy and should be replaced.
Advice for women with a history of mental health problems
See separate article Antenatal Mental Health Problems.
- The risk of stopping treatment has to be weighed 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.
- 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. 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 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.
- Women with severe depression should be referred to a specialist in psychiatry.
Bipolar affective disorder
- All women with a history of bipolar disorder who are considering pregnancy should be referred to a specialist for assessment and advice about medication.
- Medication may adversely affect pregnancy outcome and need changing. Lithium, valproate, lamotrigine, and carbamazepine would normally be stopped.
- 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.
Advice for women who require genetic screening
- Identify women at high risk of haemoglobinopathy with history and family of origin questionnaire. Further information is available on the Public Health England sickle cell and thalassaemia screening website.
- 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.
Further reading & references
- Antenatal care; NICE Clinical Guideline (March 2008)
- 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.
- 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.
- Pre-conception - advice and management; NICE CKS, June 2012
- RCOG Statement on later maternal age; Royal College of Obstetricians and Gynaecologists, 15 June 2009
- Smoking Cessation Services; NICE Public Health Guidance (Feb 2008)
- Dietary interventions and physical activity interventions for weight management before, during and after pregnancy; NICE Public Health Guidance (July 2010)
- Chlamydiosis (Enzootic Abortion of Ewes) and risks in lambing season; Public Health England, December 2012
- Health and Safety Executive; source of advice regarding specific occupational hazards
- 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 and Pregnancy; Royal College of Obstetricians and Gynaecologists (2006)
- Varicella: the green book, chapter 34 (immunisation against infectious disease); Public Health England
- Diabetes in pregnancy: Management of diabetes and its complications from pre-conception to the postnatal period; NICE Clinical Guideline (March 2008)
- Hypertension in pregnancy; NICE Quality Standards (July 2013)
- ACE Inhibitors in Early Pregnancy; Medsafe (New Zealand), June 2013
- The Epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care (women and girls); NICE Clinical Guideline (January 2012)
- Depression - antenatal and postnatal; NICE CKS, revised January 2013
- Sickle Cell & Thalassaemia screening across the UK; National Screening Portal
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Hayley Willacy
Dr Mary Harding
Dr John Cox