Wednesday June 17 2009
Women should have a baby before the age of 35 or “risk missing out on motherhood”. This was the stark message from the Daily Mail. The newspaper said that there is concern about rising infertility rates among women who delay starting a family and that new evidence demonstrates that it is increasingly difficult for women to become pregnant after the age of 35. It also said that women over 35 have a higher risk of miscarriage.
The news is based on a report by the Royal College of Obstetricians and Gynaecologists (RCOG). The College specified that the optimal age for childbearing is 20 to 35. The newspaper reported that leading obstetricians and fertility specialists in the UK have often warned that putting off having children until after this age is “defying nature”.
What is the basis for these current reports?
The news story was based on a publication by RCOG. In this report, RCOG outlined its position on the issues associated with the reproductive changes that come with later motherhood. It makes several recommendations and discusses the implications that later motherhood has in relation to current practice.
The College’s recommendations include greater education on the fact that the best age for childbearing is between 20 and 35, and further research into IVF methods and other assisted reproductive technologies
How does ageing affect the chances of conceiving?
The age at which women first become mothers in the UK is continuing to rise, but as women get older the number and quality of egg cells that are produced by the ovaries declines. About 10% of women are affected by early ovarian ageing but there is currently little that can be done to identify this condition. Infertility and difficulty in conceiving can cause great emotional distress to couples.
Women should ideally be free to choose when to start a family based on personal and professional circumstances, but very little can currently be done to reverse the underlying biological factors that determine reproductive ageing.
How successful is IVF for older women?
While in vitro fertilisation (IVF) can potentially help many women conceive, much like unassisted conception it is far less successful as women get older. The live birth rate for women under 35 undergoing IVF is 31%, but the success rate is less than 5% for women over 42.
This is because the quality of the eggs harvested in assisted techniques such as IVF deteriorates with age. These techniques stimulate the release of more egg cells but cannot compensate for the effects of reproductive ageing on egg quality.
While newer preservation techniques are designed to freeze eggs from younger women and allow postponed pregnancy at a later age, there is currently little evidence to support their use.
What are the health risks of late pregnancy?
As women get older, both mothers and babies face an increased risk of pregnancy-related complications and health problems. These are due to changes in the reproductive system and the increased likelihood of general health problems that comes with age. Problems include:
- Greater difficulty in initially conceiving a child, with the personal and psychological difficulties that this can cause.
- Increased risk of complications for both mother and infant during pregnancy and delivery (although the actual size of the risk may be small).
- Greater risk of general maternal health problems, such as high blood pressure, which can contribute to complications.
- Higher risk of miscarriage in women above the age of 35.
- Higher risk of having twins or triplets, which is itself associated with higher risk of complications.
- Increased chance of having a baby with a congenital abnormality, such as Down’s syndrome.
- Increased risk of pre-eclampsia.
- Increased risk of complications during delivery, such as prolonged labour, need for assisted delivery or Caesarean section, or stillbirth.
What does this mean if I am planning a late pregnancy?
The problems of childbearing in later life that were addressed in this report have long been recognised. Many women planning on becoming pregnant in later life will be well aware of some of the possible difficulties in conceiving or the risks of complications. However, the age at which a woman becomes a mother is governed by a number of complex personal, social, professional and life circumstances, which means that it cannot always be easily planned.
Women should not be overly concerned by this report, but should be aware of the recommendations. These include an awareness of the risks of genetic disorders and the screening tests available, ensuring any medical conditions are managed and stable (for example, high blood pressure, diabetes or obesity) and ensuring that folic acid and vitamin supplements are taken around the time of conception. A woman's health should be as optimal as possible prior to pregnancy, which means maintaining a healthy weight and eating a balanced diet, taking regular exercise, limiting alcohol and not smoking.
Many women who become pregnant in their late 30s and early 40s have perfectly healthy pregnancies and babies. All pregnant women and those planning pregnancy, regardless of age, should be fully informed, receive optimal care and support and the appropriate medical attention required to meet any needs that arise from becoming a mother.