Pregnancy at an older age: what the risks mean and how care works

There is no single point at which pregnancy becomes high risk. The term advanced maternal age is used in maternity care to flag that age-related risks may be more relevant, and different NHS pages use different thresholds depending on the condition: 35 or over for miscarriage risk, 36 and over for seeing a GP earlier about fertility, and 40 or over for pre-eclampsia and gestational diabetes.

The label does not describe an illness. It describes a group in whom certain things are looked for more carefully. Knowing which things, and why, helps you ask sensible questions at the booking appointment.

The NHS lists age alongside general health and any fertility issues among the things that affect the chance of getting pregnant. It says to speak to a GP before trying if you live with a condition, take medicines or have a fertility issue.

The NHS says several things affect the chance of getting pregnant, including age, general health, fertility problems and how often you have sex. It gives figures for those aged 39 or under, and in its infertility guidance says that more than 8 out of 10 couples where the woman is under 40 will conceive naturally within a year if they have regular unprotected sex every 2 or 3 days.

It advises seeing a GP if you have not conceived after a year of trying, and sooner if you are aged 36 or over or already aware of possible fertility problems. If assisted conception is considered, the NHS says that private treatment is available but can be expensive with no guarantee of success, and that you should choose a clinic licensed by the Human Fertilisation and Embryology Authority (HFEA). It also notes that treatments such as IVF can cause complications, including multiple pregnancy and a slightly increased risk of ectopic pregnancy.

Before trying, the NHS recommends taking folic acid and vitamin D, stopping smoking and alcohol, eating well, keeping to a healthy weight and checking vaccinations and cervical screening, and says not to stop prescribed medicines without talking to your GP or specialist.

The following are the age-related items named in NHS information. In each case age is one of several risk factors, and absolute risks are individual.

The NHS says screening tests are offered to everyone in pregnancy, are free, and are your choice. They include screening for sickle cell and thalassaemia, infectious diseases, the 12-week scan, the combined test for Down's, Edwards' and Patau's syndromes between 11 and 14 weeks, and the 20-week scan. Screening tells you whether your baby has a higher or lower chance of a condition but cannot say for certain, and if the chance is higher you will be offered more information and further tests.

If you have a health condition like diabetes or high blood pressure, or have had previous complications, the NHS says you may be offered additional tests or monitoring. You can choose all, some or none of the tests, and can change your mind later although some tests must be done at certain times.

For pre-eclampsia, the NHS lists a severe headache that does not go away with simple painkillers, vision problems such as blurred vision or flashing lights, pain below the ribs, sudden swelling of the face, hands or feet, feeling very unwell, persistent heartburn and being sick, and says any of these can be serious and need to be checked immediately. If you are pregnant, call your maternity unit; if you have recently given birth or cannot reach your unit, call 111.

For gestational diabetes, the NHS notes that it does not usually cause symptoms and is mostly found at screening, but that raised blood sugar may cause increased thirst, needing to pee more often, a dry mouth, tiredness, blurred eyesight or genital itching, many of which are common in pregnancy anyway. Speak to your midwife or doctor if you are worried about any symptoms.

Antenatal care is the same NHS pathway for everyone, with additions when age or other factors raise particular risks. The NHS says it is important to attend your antenatal appointments because that is where the midwife can work out whether you are at risk of pre-eclampsia, and that if a midwife or doctor thinks you are at higher risk they may prescribe aspirin from week 12 or calcium supplements, but not to start these unless advised.

If gestational diabetes is diagnosed, the NHS says most women have otherwise normal pregnancies with healthy babies, but it can cause problems such as a larger than usual baby, which may increase the likelihood of induction or a caesarean, polyhydramnios and premature birth, and the risks can be reduced if it is detected early and well managed. If pre-eclampsia develops, it is often safer for the baby to be born early, in some cases before 37 weeks, and your care plan will be agreed with you.

Most antenatal care in the UK is through the NHS, with a midwife as the usual first contact and referral to an obstetrician where extra monitoring is needed. Some people also choose private obstetric care or private fertility treatment. The screening tests and clinical thresholds are broadly the same; private care mainly changes choice of consultant and appointment timing. If you choose private fertility treatment, the NHS advises using an HFEA-licensed clinic.