This section contains some eye-opening information on fertility, and other factors you should take into consideration when thinking about starting a family. There is a lot of information on the internet about fertility—we encourage you to do your own research. Fertility Associates has a raft of free information available on their website: http://www.fertilityassociates.co.nz/
Fertility
The average age of a woman’s first birth in New Zealand is 28 years of age. Even though we are living longer, fertility is hardwired into your DNA and the fertility window for women remains the same. Surveys have consistently shown that people over-estimate how long their fertility will last by about 10 years. In addition, there is widespread belief that fertility treatments such as IVF can overcome the effects of age.
| Your fertility | ||
| In your 40s | In your 30s | |
| Chance of a baby per month (natural conception) | Woman aged:
40: 6% 43: 2% 46: 1% 49: 0% |
Woman aged:
30: 22% 33: 18% 36: 13% 39: 9% |
| Chance of a baby per IVF cycle | Woman aged:
40: 24% 43: 8% 46: 4% 49: 0%, would need egg donor |
Woman aged:
30: 48% 33: 44% 36: 38% 39: 28% |
| Impact of age | The quality of a woman’s eggs and her ovarian reserve decline with age. Most women go into menopause between 50 and 55, approximately 10 years after their fertility ceases. There is also an increased risk of genetic abnormalities as the woman ages.
In regards to men, being aged over 50 is associated with a longer time to conceive, separately from the effect of his partner’s age. This doesn’t happen if using IVF as the number of sperm around the egg is greatly increased. There is also a moderate increased risk of genetic abnormalities as the man ages. |
|
| Impact of lifestyle—male and female | Poor lifestyle can reduce fertility, but a healthier lifestyle cannot compensate for the impact of age. | |
| Publicly funded treatment | Unfortunately public funding does not cover the cost of treatment for women aged 40 years and over. You must have been assessed and if eligible, enrolled for a publicly funded consultation or treatment before you turn 40. | You are eligible to be assessed for a publicly funded consultation and/or treatment up until the female in the partnership turns 40 years old—as long as you meet the criteria as set by the Ministry of Health. |
Chromosomal abnormalities
The table below shows how the risk of delivering a baby with chromosomal abnormality increases with maternal age (in the first trimester of pregnancy, the risk that the foetus has a chromosomal abnormality is higher than at birth, because many affected foetuses die naturally during the pregnancy).
|
Maternal age (years) |
Risk for Trisomy 21 | |
| At birth | At 12 weeks | |
| 20 | 1 in 1527 | 1 in 898 |
| 25 | 1 in 1352 | 1 in 795 |
| 30 | 1 in 895 | 1 in 526 |
| 32 | 1 in 659 | 1 in 388 |
| 34 | 1 in 446 | 1 in 262 |
| 36 | 1 in 280 | 1 in 165 |
| 38 | 1 in 167 | 1 in 98 |
| 40 | 1 in 97 | 1 in 57 |
| 42 | 1 in 55 | 1 in 32 |
| 44 | 1 in 30 | 1 in 18 |
