Timing your pregnancy

Most people take their fertility for granted, assuming when contraception is stopped, pregnancy will follow in two or three months. For around 65% of New Zealand couples this is indeed what will happen, however, around 30% of women may take up to a year to become pregnant. For some couples it is important to plan the date that they conceive. There are many reasons for this, the most pressing generally being employment requirements or health problems. This topic is designed to help couples who have no known fertility problems plan the timing of their pregnancies.

Giving mother nature a hand

Pregnancy occurs when an egg is fertilised by sperm around the date of ovulation (when the egg is released from the ovary and begins to make its way down the fallopian tube towards the uterus or womb). Ovulation usually (but not always) occurs 11-16 days before menstruation. The trick to getting pregnant quickly is to work out exactly when ovulation occurs and to have sex around this time.

This is a general outline of a woman's 28-day cycle but fertility patterns vary from woman to woman and from cycle to cycle.

The female menstrual cycle - days 1 (first day of period) to 28

M = menstrual days (bleeding)
F = fertile days
I = infertile days
14 = date of ovulation

The calendar method

The simplest (and least accurate) way is to count 12 to 16 days from the first day of your last menstrual period. This will give you an approximate time of ovulation. Having sex during these four days means that you are more likely to become pregnant. This method is not particularly reliable because it assumes that every woman will ovulate on day 14 of every 28-day cycle.

Fertility awareness

The most accurate way of determining ovulation requires a bit more work and involves the following two parts. You will need to stop the contraceptive pill or injection before you notice these cyclical changes.

Getting to know your basal temperature rhythm

Your temperature changes throughout your menstrual cycle. It is usually lower before you ovulate and higher after ovulation. This method will show when ovulation has occurred, not when it is likely to occur, so you may use it for planning the following month.You will need to purchase a thermometer and take your temperature every morning as soon as you wake up (before you move anywhere) and then record the reading on a chart beside the bed. You can get a special chart to make this recording easier from the Natural Family Planning Inc.

Your fertile mucus symptoms

Throughout your menstrual cycle the mucus in your vagina alters. As ovulation approaches the mucus changes in texture, volume and sometimes colour. There is also a change in sensation of dryness and wetness in the genital area. The exact nature of this change varies from women to women, however, fertile mucus is generally watery, clear, copious and you can stretch it between your fingers.

Infertile mucus is thicker, sticky and is cloudy or opaque in colour. There will be less of it and at some times of the month may be hard to see at all. Recording the type and amount of mucus can help you pinpoint when ovulation occurs. The last day of fertile mucus is the generally the day before ovulation occurs.

Cervical changes

For the truly committed you can also check changes in your cervix. Your cervix softens when ovulation approaches. After ovulation it gets firmer and lower. Recording these changes each day can also give a clearer picture of when ovulation is occurring.

What else can you do to improve your chances of becoming pregnant?

To improve the chances of conceiving the male sperm count needs to be as high as possible. Repeated ejaculations over a short period will lower the sperm count, so it is wise to ejaculate no more than every two days during the fertile period (as frequent ejaculations in a short space of time decrease the level of sperm in the ejaculatory fluid).

• Smoking (cannabis and tobacco) and drinking alcohol have also been shown to reduce the sperm count and quality. Quit smoking
• There is no evidence to show that different sexual positions improve or affect the chances of becoming pregnant.
• Ensure that you and your partner are in good health and enjoying a well-balanced diet.

When to get more help

If you do not become pregnant after one year (or 6 months if you are older than 35), despite stopping all contraception and having sex during the woman's fertile period, then you should visit your family doctor. One in 8 couples in New Zealand requires some form of medical assistance to achieve a pregnancy.

The above information is only a guideline. Qualified natural family planning advisors teach couples to understand their own unique pattern to maximise the chances of conception.

If further medical assistance is needed to conceive, the woman's chart provides valuable information to the specialist.

Original material supplied by Natural Fertility New Zealand. Reviewed by everybody, March 2005.