Pregnancy and the Older Woman

When it comes to pregnancy, age is important and can affect the nature of your experience. Ann Bracken outlines the implications of pregnancy in the post 35 maternal age group.

Compared to our grandmothers’ generation, today’s thirty and forty-somethings look and feel so young and healthy that, it is difficult to remember that their reproductive life-span is just as short as it was one hundred or one thousand years ago. 30 years ago, the average age of new mothers was 26. Now it is 30 and climbing rapidly.

Conceiving a baby, especially when longed for, is usually the most special time of a woman’s life. The miracle of a newborn melts hearts of all ages, male and female. Since the beginning of time, the arrival of a small infant has been as wonderful and natural as changes in the seasons. However, nowadays this natural wonder may also require a high level of planning to ensure that when junior arrives there is room in the manger and a roof overhead!

Planning for the ‘right’ time to have a baby is a relatively new concept in Ireland and this has been reflected in a significant increase in the age of women giving birth here, over the past 15 years; from 29 to 32 within marriage and 22 to 26 outside of marriage. This may be as a result of ever increasing mortgage replayments and an escalation in the cost of living, or resulting from an expanding number of life choices for women - we now live in a world where choosing to be a mother is an option and not a privilege.

Diagnostic Screening Tests

The problem is that postponing parenthood has its risks. There are factors to consider if a woman is wishing to achieve a pregnancy, later in life. Age is a factor in certain foetal abnormalities and there are higher rates of maternal diabetes, placental insufficiency, high blood pressure, or of having a Down’s Syndrome baby if the mother is older. The mother may have more to carry than the fact she is pregnant - with certain tests being required, the anxiety of these tests may outway the excitement of the pregnancy at times.

Unfortunately, human beings, as a species, are not very fertile. Even young couples with normal fertility (and trying quite hard) have only a 25 – 30% chance of establishing a pregnancy each month they try. When a woman reaches her mid-30’s, this monthly chance drops to 10 – 15%. By her early 40’s it is less than 5% a month AND she is facing a 40% chance of miscarriage even if she can achieve a positive pregnancy test. If there are other factors influencing a couples’ chance of success such as irregular ovulation or poor sperm parameters, the chance is even lower. In addition, the risk of chromosome abnormalities such as Down’s syndrome increases very rapidly from 37 years onwards.

Since fertility is to a large extent genetically inherited, a woman can get a good idea of her likely reproductive prospects by finding out about her mother’s experience. If her mother had difficulty getting pregnant after her late twenties and had a relatively early menopause (younger than 45 – 50years) there is a chance that her daughter may experience similar problems. Women whose mothers and grandmothers had babies effortlessly in their late thirties or early forties may be reassured that they will probably be able to do the same.

Screening tests for women over the age of 37 are offered to determine any abnormality in the foetus with particular focus on testing for Down’s Syndrome, due to the increased risk of chromosomal abnormality in older women. The risk of having a baby with this condition rises with advancing maternal age, from a 0.4 chance at the age of 20 to 3.1 chance at 35, and 10.5 chance at 40 years of age. The statistics show that 1 in every 2,000 babies born are Down’s babies.

The first screening test for women over 35 is the Nuchal scan. This ultrasound scan assesses the foetus at between 11-13 weeks. If a shadow of a particular size and shape is present at the back of the foetus neck, this can indicate a higher risk of chromosome defects such as Down’s Syndrome. If the test indicates a probability, amniocentesis will be offered to confirm the diagnosis.

Amniocentesis is the process which removes a sample of amniotic fluid that surrounds the baby in the uterus when the pregnancy is between 15-20 weeks. However, as this test can carry a risk of miscarrige, careful consideration and even counselling may be advised in advance of taking the test.

What needs to be considered by each mother is what they would do with the information that the specialist tests will provide. Will this information be reassuring - or will it put enormous emotional strain on the mother and indeed father to be? Regardless of whether the tests are advised and taken, pre-natel care is particularly important for women of advancing age.

Also, for women who are planning a pregnancy later in life, it is important that they adopt a healthy lifestyle – A good diet, exercise and relaxation time all need to be incorporated into daily life, to increase their potential for a healthy pregnancy.

Although, there may be risks to the higher age group women, the reality is that most women have healthy pregnancies and babies.

TIPS FOR THE OLDER WOMAN CONSIDERING PREGNANCY

·                    Avoiding alcohol and smoking will promote your health and the health of your baby.   

·                    Proper pre-natal care will optimize your chances of having a healthy baby.

When choosing an antenatal clinic, discuss your preferences and find out what options are available to you – age may be a factor in some delivery options, i.e. homebirths. Do some research into the philosophy or practice of the particular ante-natel support you are choosing.

·                    Begin taking a prenatal vitamin. Ensure you choose a vitamin especially for pregnancy, as this will contain the correct amount of folic acid and will not contain Vitamin A which is not recommended to take during pregnancy.

 Health and lifestyle factors play an important role in influencing a woman’s natural fertility:

• Smoking is probably the single most significant factor — women who are life-time smokers will undergo their menopause at least two years ahead of schedule and will become sub-fertile sooner and have a higher risk of miscarriage. 
• Women who are significantly below or above their ideal weight are also at a higher risk of fertility problems and/or pregnancy complications.
• Women who have had pelvic surgery, endometriosis or recurrent pelvic infections also seem to have a lower chance of successful pregnancy, probably because their store of viable eggs is reduced.

Clearly, a nutritious diet, adequate but not excessive exercise and a healthy, low-stress lifestyle are all conducive to good fertility – but it is generally recognised that trying to get pregnant and repeatedly ‘failing’ can drive even ‘health-nuts’ to booze and cigarettes!

Fertility treatments

Intra-Uterine Insemination

Some women trying to conceive later in life may be helped by fertility treatments such as Intra-uterine Insemination (IUI) in conjunction with ovarian stimulation. Stimulated IUI is a treatment designed to enhance a couple's natural fertility without resorting to 'high-tech' treatments.

The woman undergoes stimulation with gonadotrophins (hormone injections) to encourage 2 eggs to mature. Throughout the drug phase, treatment is monitored by ultrasound and when the follicles are ready, a final injection of hCG is given to provoke ovulation.

Approximately 30 – 40 hrs later, specially prepared sperm (ideally 5 million, highly active sperm) are inserted through the cervix in a fine plastic tube and deposited high up in the uterus, near to the opening of the Fallopian tubes. Putting very good sperm in exactly the right place at the right time boosts natural fertility. Success rates with stimulated IUI are typically 10 – 15% per cycle.

In-Vitro fertilisation

Many women in their late thirties or early forties choose to have IVF treatment even if there is no apparent explanation for their failure to conceive other than their age. IVF is recognised to be an effective (and diagnostic) treatment for this so-called ‘unexplained’ infertility. Women in this age range are also acutely aware that their biological clocks are running down very fast and they cannot risk waiting (or wasting!) another 6 months to ‘give Mother Nature another chance’ since success rates of fertility treatments such as IVF depend on the age of the woman concerned.

The success rates for IVF (approximately 25% per cycle for women under 40 and 15% per cycle for 40+) depend upon a woman having good ‘ovarian reserve’, that is being able to recruit a good number of ovarian follicles in response to the stimulating drugs used in IVF. Assessing ovarian reserve is therefore a very important part of counselling a couple about their individual chances of success with ‘high-tech’ fertility treatments such as IVF. Age, past medical history, FSH (follicle stimulating hormone) levels and ovarian scan results all provide useful information for predicting the likely chance of success with treatments such as IVF. In addition, some fertility specialists are now advising women to have their inhibin B level assessed. This simple blood test, (taken during day 3-6 of the menstrual cycle), provides a direct measurement of ovarian reserve.

The future

It is now possible to freeze human eggs and then thaw them and use them to generate embryos for transfer in an IVF cycle. At the moment this technology is mainly used to help young women who are facing a diagnosis of cancer. Lifesaving chemotherapy or radiotherapy will probably render them sterile and the technique of egg freezing allows them to ‘bank’ their oocytes (eggs) for later use, so that they have a chance of giving birth to their own genetic children.

This same technology could be applied to allow young women who were not yet in a position to become pregnant to store their eggs for use later when they wished to start a family. Clearly this new approach to ‘family planning’ may meet with some resistance. For future generations though, it could offer a solution to the ‘career women’s’ dilemma about when to start a family.