Pregnancy over 40
According to the ONS, more women are embarking on motherhood later in life, with pregnancies over the age of 40 on the rise.
Of course, there's some level of risk in all pregnancies; however certain risks are increased when you're older. It's not all negative - there's plenty of mums who have great things to say about later parenthood. But if you are entering your fourth decade and pregnant, or trying to conceive, here's a few things to think about.
The Royal College of Obstetricians and Gynaecologists suggest that the 'optimal age' for childbearing is 20 to 35; however, as the above figures show, this is not necessarily a reality. Women 35 and over are deemed to be 'older', as this is when fertility begins to decline. Women may find it harder to conceive at this age, and men's fertility also declines as they approach their 40s.
NHS statistics say that at age 35, 94 out of 100 women will get pregnant after three years, but by age 38, only 75 out of 100 will do so.
You may want to try fertility treatments, although the success rates of options such as IVF also drop with age.
If you do get pregnant, interestingly there's also more chance of you having twins. This is due to the hormone FSH which is produced as fertility declines. If you're expecting multiples, you'll get some additional antenatal care.
If you are an older mother, you may be seen by a doctor or obstetrician rather than a midwife at antenatal appointments, particularly if this is your first pregnancy. Medics might refer to you as 'elderly primagravida' – this simply means that you're a first time mother over 35.
You will undergo all the regular pregnancy tests and scans, but it may also be recommended that you have additional tests to check for particular things. These are optional, so you can of course decline, but they may be able to pick up on certain irregularities which standard checks cannot.
A number of blood tests are done around 12 weeks for all pregnant women. These are testing for things like anaemia, HIV, your rhesus status, and inherited blood diseases.
Further screening can be carried out to look for specific irregularities or concerns relating to the foetus. As an older mother, if you're considered to be higher risk, these may be recommended.
A nuchal translucency scan can indicate a higher risk of genetic abnormalities, particularly Down's syndrome. This needs to be done between 11 and 13 weeks, it may be offered as part of your 12-week scan.
Another blood test done alongside this, known as combined screening, can also look at the levels of certain hormones, which may indicate a higher risk of chromosomal abnormalities.
As the nuchal test and the combined screening only give an indication of risk, you may be offered a more definitive test - chorionic villus sampling (CVS) or amniocentesis – to get a more accurate indication of any genetic abnormalities. These are invasive tests, and so carry some risks to you and your baby. The decision as to whether you take them, as with all pregnancy screening, is up to you.
Chrorionic villius screening
CVS takes a sample of cells from the placenta, to look at the foetus' DNA. It is offered between weeks 10 and 13 and can detect:
- Genetic abnormalities such as Down's syndrome
- Cystic fibrosis
- Muscular dystrophy
- Inherited blood disorders such as sickle cell anaemia and thlassaemia
- Metabolic disorders such as antitrypsin deficiency
- Mental health conditions such as fragile X syndrome
- CVS doesn't test for physical problems such as spina bifida.
Amniocentesis involves taking a sample of the amniotic fluid, which is the water that surrounds your baby in your womb. Normally done between weeks 16 and 22, it can be used to test for:
- Down's syndrome
- Edwards' sydrome
- Patau's syndrome
- Sickle cell disease and Thalassaemia
- Cystic fibrosis
- Muscular dystrophy
- Tay-Sachs disease
- Neural tube defects such as spina bifida
- Rhesus disease
Chromosomal abnormalities, such as Down's syndrome and Patau's syndrome, occur when there are less or more chromosomes than usual, or when the sets of chromosomes become altered.
The chance of any chromosomal abnormality rises from one in 500 at the age of 20, to one in 60-70 at age 40, according to NICE.
Probably the most well-known chromosome abnormality; Down's syndrome is caused by the presence of an extra chromosome in the child's DNA.
The risks of Down's Syndrome based on maternal age are:
- 20 years - 1 in 1,500
- 25 years - 1 in 1,300
- 30 years - 1 in 900
- 35 years - 1 in 350
- 40 years - 1 in 100
- 45 years - 1 in 30
There are some increased health risks for older mothers, particularly those with a history of high blood pressure, diabetes, or other chronic disorders. In some cases, these can lead to complications during the pregnancy or labour.
High blood pressure and pre-eclampsia
Your blood pressure will be checked at every appointment, and one of the things doctors are checking for is pre-eclampsia. Raised blood pressure can be a symptom of pre-eclampsia, and there is a higher chance of it affecting women over 35.
Pre-eclampsia reduces the blood flow to the placenta, which can then restrict your baby's growth because not enough oxygen or nutrients are getting through.
Women with pre-existing diabetes need to be aware that it may become harder to control during pregnancy. It can also lead to complications during labour, and in some cases it may be recommended that labour is induced, or a caesarean section offered, after 38 weeks.
Gestational diabetes occurs when you have too much sugar in your blood because your body can't produce enough insulin (which converts blood sugar into energy) to meet the extra demands of pregnancy - ie incubating a growing baby and hormones produced by the placenta that resist insulin.
If you are at high risk of gestational diabetes you will be given a glucose tolerance test, which involves two blood tests after fasting, at 28 weeks or earlier.
Sometimes, diabetes can affect foetal development. You may be offered further tests, such as cardiac screening of the foetus, as part of your antenatal appointments. Monitoring the baby's blood glucose levels and their heart after birth is also recommended in some cases. (Source: NICE)
Approximately 1 in 5 pregnancies will end in miscarriage, and the rate is increased in women over 40.
Miscarriages in the first trimester generally occur because the foetus is not developing properly. This can be linked to chromosome abnormalities, though the cause is often not identified.
All births between 24 and 37 weeks are considered preterm, with babies delivered at 26 weeks or earlier being particularly high-risk. Premature babies are likely to have low birth weight, as well as having increased chance of other health problems or disability. This may include: respiratory complications, mobility problems, visual or hearing impairment. The survival rates for babies born between 28 and 37 weeks continue to improve, with an 11% decrease in preterm mortalities in the last eight years. (Source: Tommy's)
If you're pregnant over 35, the chance of a premature birth is higher. In England and Wales, 9.5% of premature births are to mothers aged 40 and over. Women pregnant with multiples are also nine times more likely to give birth early.
Women over 40 are twice as likely to have a stillbirth at 39-40 weeks pregnant, compared to women under 35 - but the chance is still only 2 in 1000, so relatively low.
Some obstetricians recommend inducing at 39 weeks if they believe that going full term would mean an increased risk of stillbirth.
Prolonged labour, complications and caesareans
Older women may find that their labour is long (12 hours or more) and there is also an increased risk of certain complications.
If you have any condition (including diabetes or high blood pressure) which may put you, or your baby, at risk during vaginal delivery, a caesarean may be recommended. This can be decided beforehand, or if complications arise an emergency caesarean may be arranged. Women over 35 are more likely to need an assisted delivery, with about 40% having a caesarean section.
There are additional risks to the mother associated with caesareans, because it is major surgery, and there's an increased chance of your baby having breathing difficulties at birth; however mostly the chance of any health issues is the same as it would be for a vaginal birth.
Getting pregnant when you're older can mean you feel the strain of tiredness and lack of energy that little bit harder throughout the pregnancy. However, with age also comes experience, independence and more stability.
What Mumsnetters say about having babies later in life:
"The main difference I've noticed is that I find the tiredness more difficult to cope with."
"I'm physically fitter and much stronger than I ever was in my twenties, when I spent far too much time drinking in smoky bars. I'm far more aware of what I eat and look after myself better, am financially more secure and much calmer and more patient than my younger self."
"I'm sure I'd still feel as knackered if I were 10 years younger."
"We are financially secure and not having to rush around juggling career/childminding/money etc etc - just as well as I am knackered most of the time!"
"I would opt every time to be an older parent than a very young one. I know now that I can devote the necessary time and attention to my child because I'm not worried that I'm missing out on opportunities for my social life and/or career as I would have been in my 20s. Older parents have a lot more to offer a child."
Last updated: about 1 month ago