High-risk Pregnancy

A pregnancy with a higher than average risk for the mother or the fetus

  • Most common under the age of 15 or over the age of 35
  • Smoking and alcohol or drug abuse during pregnancy are risk factors
  • Genetics as a risk factor depends on the cause

For the majority of women, pregnancy progresses well except for some minor problems, such as tiredness and swollen ankles (see Common complaints of normal pregnancy). However, pregnancy is not without risks. Although the risk of death for both mother and fetus is low, it increases in certain situations. Some women are at higher risk of developing problems in pregnancy, and one of the functions of routine antenatal care is to identify these women so that they can be monitored and receive additional treatment if needed.

What are the risk factors?

There are many different risk factors that may lead to a high-risk pregnancy. Women under the age of 15 or over the age of 35 are more likely to have problems, as are women who have a small build or who are overweight. Other risk factors in pregnancy include certain lifestyle factors, such as smoking; a history of problems in previous pregnancies; and pre-existing illnesses.


Women under the age of 15 who become pregnant are at increased risk of going into labour before the end of the pregnancy (see Premature labour). They are also at risk of certain complications during pregnancy, such as pre-eclampsia and eclampsia in which blood pressure is high.

Women over the age of 35 are more likely to have pre-existing disorders, such as noncancerous tumours in the uterus (see Fibroids) or diabetes mellitus. They are also at greater risk of developing pre-eclampsia or diabetes while pregnant (see Diabetes developing in pregnancy), which may place the pregnancy at risk. There is also an increased likelihood of the fetus having a chromosomal abnormality, such as Down’s syndrome, if the mother is over the age of 35.

Physical factors

Women who have a small build and a small pelvis are at greater risk of a delayed first stage of labour, particularly if they are carrying a large baby who cannot easily fit through the pelvis.

Lifestyle factors

Having a poor diet, smoking, and abusing alcohol or drugs during pregnancy all increase the risk of problems occurring, including miscarriage, premature labour, and intra-uterine growth retardation.

Problems in previous pregnancies

Any problems in a previous pregnancy, such as a premature labour or stillbirth, tend to increase the risk for the current pregnancy. A woman who had a small baby in a previous pregnancy will be more likely to have another baby who is underweight.

Pre-existing illnesses

Any disorder that is already present (see Pre-existing diseases in pregnancy), such as diabetes mellitus, epilepsy, or high blood pressure, may lead to problems for mother and fetus. Changes to the mother’s medication and additional monitoring of mother and fetus may be necessary both before and during the pregnancy.

What might be done?

At your first antenatal visit, your doctor or midwife will examine you and ask you questions to determine whether or not you are at increased risk. If you are, you will need additional monitoring and possibly specialized treatment.

If you have a high-risk pregnancy, you will probably need more frequent antenatal visits. You may be offered additional tests if you are at increased risk of having a baby with a gene or chromosome disorder (see Antenatal genetic tests). Frequent blood tests may be needed to monitor any pre-existing diseases, and additional ultrasound scans may be needed to monitor the growth of the fetus (see Ultrasound scanning in pregnancy). You may be supervised by several doctors and specialists.

What is the prognosis?

With monitoring and modern delivery techniques, most problems can be treated successfully. Although complications are more likely to occur in a high-risk pregnancy, modern treatments have improved the outlook.

Health Action: Exercise and Relaxation in Pregnancy

Test: Routine Antenatal Care

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

Back to top