Understanding your fertility

It is only natural when faced with fertility problems later down the track that we may regret not valuing our fertility earlier.

For most couples, the chance of getting pregnant is generally pretty good; others however, may face the challenges of infertility.

For the average couple, there is a 20-25% chance of conception per month and only 65% of couples will have conceived in the first six months. Most couples with relative infertility will usually go on to conceive in time, and only 5% of couples have complete infertility.

There are a variety of reasons for pregnancy not happening. About 30% of causes can be attributed to a problem with female fertility, 30% to a problem with male fertility and in about 20% of cases there is a problem with both partners. In approximately 20% of cases, there is no clear and definitive cause for infertility – in these instances infertility remains frustratingly unexplained.

Fertility factors

A range of lifestyle factors can influence overall fertility, these include:

Age

Age is the most important factor when it comes to conception. It has a significant effect on the chance of conception per month. Even for a ‘normal’ fertile couple, the older you get, the longer the time it takes to conceive. Fertility levels diminish with age particularly with women, but recent research also indicates that age can also play an important part for men.

A woman’s most fertile window is approximately between the ages of 16 to 25. On average, it can take about three to four months for a 25 year-old to conceive if everything is normal. From 35 onwards there is a significant drop in the chance of conception per month. The average 35 year old takes at least six to eight months to conceive. Women over 35 should wait no more than six months before seeking help if there are any problems falling pregnant.

New Zealand women are now having their first babies later in life than any other women in the world, the average age is now 30 – up from 25 in their parents’ day. Whether it’s due to study, travel, career or money, the trend towards later marriages, smaller families and delayed parenthood is continuing, meaning many women are deferring trying to get pregnant until they are in their 30s or 40s. According the 2006 New Zealand Census, 2351 women had babies aged 40 – 50, compared with just 1253 a decade ago and only 399 in 1980.

The dilemma with increasing age is that your biology can severely limit the chance of conception per month, when the need to conceive quickly may be at its greatest.

Health and wellbeing

Your overall state of health can have a huge impact on your fertility, so a healthy approach to both diet and exercise is essential when trying to get pregnant.

Diet can affect fertility in the short and long term. Weight-loss and a significant lack of body fat are related to the cessation of ovulation in women. For most women, for the body to sustain ovulation a healthy body mass index (BMI) is needed – this is normally between 20 – 25. Obesity can also impair chances of conceiving as it affects ovarian function. A BMI of more than 25 is associated with increasing episodes of abnormal menstrual cycles. Pregnancy in overweight women is also associated with problems such as maternal diabetes and high blood pressure.

Moderate physical activity taken regularly when trying to conceive, and when pregnant is safe and beneficial for most women. Low-impact and realistic exercise is advised. Overall a healthy weight, diet and moderate exercise means improved ovulation, better pregnancy rates and healthier babies.

Cigarettes, alcohol, caffeine and other drugs

• Overall, smokers are only 60% as likely to conceive per month as non-smokers.
• Cigarette smoking has been shown to decrease the sperm count in men, and in women can increase the incidence of miscarriage, ectopic pregnancy, and premature births.
• Alcohol is also shown to affect the sperm count, and when abused it can also upset menstrual cycles in women and can also increase the risk of babies with birth defects.
• Caffeine, a more widely used drug – can affect chances of conceiving if more than two cups are drunk per day.

 

There is only indirect evidence that the use of recreational drugs can reduce the chances of conception, however in pregnant women there is an increased risk of kidney problems occurring in the developing baby.

Requirements for a balanced diet

• Folic acid: Having enough folic acid is important in pregnancy, as it minimises the chances of having a baby with neural tube defect (spina bifida). It is found in most plant foods, especially green leafy vegetables, wholegrain breads, cereals and legumes (peas, beans and lentils). However, it is important to take folic acid tablets to make sure your intake is sufficient (0.8 mg per day until 12 weeks of pregnancy). Also, folic acid combined with a general multivitamin such as in Elevit has been found to reduce heart, urinary tract and cleft lip abnormalities
• Vitamin A: Although vitamin A is important for normal development, high doses have been shown to be harmful in early pregnancy and can cause birth defects. Fruit and vegetables (particularly yellow vegetables like carrots) are a good natural source of vitamin A. Vitamin A supplements should not exceed 10,000 IU (international units) and high vitamin A-containing foods, such as liver, should probably be avoided in pregnancy.
• Iron: A reasonable dietary intake of iron is needed during pregnancy. The best source of iron is red meat. If you don’t eat much red meat, you may need an iron supplement. You should discuss this with your caregiver.
• Calcium: Pregnancy imposes considerable calcium demands and if you don’t eat dairy products then you may need to take calcium supplements. Another good source of calcium is sardines.
• Iodine: It is also important to have a reasonable intake of iodine, as it is important for thyroid hormones which are needed for normal development of your baby. You can get sufficient iodine from iodised salt.
• Listeria: This is a common bacteria present in soil, water, plants and sometimes in human and animal faeces. Good hygiene in food preparation is very important in pregnancy to prevent contamination with listeria. Most of us are exposed to listeria frequently without ill effects; however, occasionally it can cause miscarriage or stillbirth. The most common foods that may contain listeria are cheeses made from unpasteurised milk, pre-cooked chicken, ham and other pre-cooked meat products, stored salads and coleslaws, and chilled pre-cooked seafood products.

   

Stress

While stress can play a part in infertility, it is very seldom the sole cause. Couples who take a long time to conceive do become stressed, but alleviation of this stress will not necessarily alter chances of conception. The stress of not conceiving is considerable for infertile couples and requires support and careful attention so it is not destructive to the relationship.
 

What else might be affecting our fertility?

Sexually Transmitted Infections

Protecting yourself against STIs is an important step towards protecting the future of your fertility. While the incidence of STIs associated with fertility problems are relatively small – around 5% – infection can potentially lead to pain, pelvic infections, ectopic pregnancy and the possible need for surgery. Whilst the avoidance of STIs is paramount, early assessment and treatment is vital.
 

Medical conditions

A range of medical conditions can also contribute to fertility problems. Some of the more common causes for female infertility may include abnormal ovulation, blocked fallopian tubes, endometriosis, polycystic ovaries, fibroids or cervical problems. In men, fertility problems may be associated with low sperm count, or abnormalities with the motility and structure of sperm, varicocele, testicular injuries or hormonal imbalances.

Environmental toxins

Exposure to chemicals or toxins may influence the ability to conceive. Considerable research is being done into the effect of occupational and environmental toxins such as lead, radiation, waste materials and pesticides on sperm count, motility and egg quality. While definitive answers are not yet available, there may be some relationship between toxins and the decline in sperm count and male fertility in recent years.