Understanding your cycle

Mother and Baby
Monday, July 14, 2008
Understand your cycle. Image: Getty

Timing is everything

If you're trying to conceive, understanding your cycle can be one of the most important things you can do.

When it comes to the baby-making process, it's a very good idea to know when to have sex and how often and to be aware of the emotional and physical changes that show that it's time for you to try to conceive.

The first step is getting to know and understand your menstrual cycle. A typical cycle lasts about 28 days and ovulation — the release of an egg from the ovaries — happens on day 14 of that cycle. The first day of your cycle is the day your period begins, so many woman are at their most fertile around the 14th day after they started bleeding.

But this all depends on how long your cycle actually is, explains Dr Lyndon Hale, chairman of Melbourne IVF. "Ovulation occurs 14 days before menstruation starts, so if a woman has a 35-day cycle, she'll be ovulating on day 21," he says.

So it's a good idea to keep a record of your cycles before you try to conceive. Note the day your period begins, then count the days in your regular cycle to work out when you've ovulated by counting back 14 days from when your next period begins. Then apply this looking forward. Your obstetrician or GP can help you work it out.

The other signs
It's not just your period that gives you clues: there are other indicators that show you're ovulating.

"There are three common cues your body will give to tell you it's the right time to conceive, such as changes in cervical mucous, an increase in basal body temperature and bodily symptoms," explains Dr Philip Goldstone, a senior doctor from Marie Stopes International Australia.

When you're ovulating you'll notice cervical mucous, usually when you go to the toilet. "The consistency is likened to that of raw egg white — it's clear and slippery and there's more of it than usual," says Dr Goldstone.

This mucous is usually present in your cervix to prevent anything passing through your vagina into the uterine cavity, but during ovulation the mucous loosens from the cervix, making it easier for sperm to cross the barrier and impregnate the egg.

Your basal body temperature also changes around the time you should try and conceive. "Following ovulation, a woman's temperature increases quite significantly, then remains higher for the rest of her cycle," explains Dr Goldstone.

You're most likely to conceive two to three days prior to your increase in temperature — you can keep track of this with a basal body temperature thermometer, which can be bought from any pharmacy.

Lastly, changes in mood, libido, appetite and sleep patterns can also be signs of ovulation. "A woman's libido starts to rise as her oestrogen levels rise," says Dr Hale. "As the follicle grows within the ovary, it produces oestrogen, which prepares the lining of the uterus to receive the embryo. Some women say they become more sexual as their oestrogen levels go up and that's a cue. Don't wait until day 14 — listen to what your body is telling you."

Sex: how often?
Now that you have worked out when you are likely to ovulate, it's important that you don't only have sex on that day. "Sperm need to be waiting when the egg is released — you shouldn't be having sex for the first time on day 14," Dr Hale says.

"If a couple has intercourse two or less times a week, we know their chances of conceiving won't be as good as a couple having sex three or more times a week."

However, more is not necessarily better. You don't need to have sex every night: every second or third day is adequate.

So if you have a 28-day cycle, Dr Hale recommends having sex on days eight, nine or 10, then every two days after that, ensuring you have sex on day 14 (or the day you actually ovulate if your cycle is longer than 28 days).

The reverse rhythm method
Couples who want to avoid pregnancy sometimes use the rhythm method to ensure they don't conceive — and the theory can be reversed if you do want to make a baby.

"The rhythm method looks at the rhythm of your cycle over 28 days," explains Dr Hale. "You're not likely to conceive five days before or after ovulation, so to not get pregnant you stop having intercourse on day nine of your cycle and you also stop when you see the cervical mucous. To get pregnant, you would reverse that."

So start having sex when you see your body's signs — like cervical mucous — and on days close to when ovulation usually starts for you.

Getting pregnant during a period
Occasionally women say they became pregnant during a period and not at the time the ovulation rulebook says they should be conceiving. How is this possible?

"Cervical mucous isn't an absolute barrier. If you have super sperm that can swim against thick currents of mucous, it may reach the female genital tract and stay there," explains Dr Hale. "We know that sperm can survive there for up to five days and in some cases that will lead to conception."

So when women fall pregnant during their period, it may be that late-surviving sperm belatedly connect with an early-released egg.

"In the high jump there are people good enough to go to the Olympics and people who are barely able to get their feet off the ground," says Dr Hale. "It's the same with sperm."

Remember the fun
Trying to conceive can become stressful as you carefully count days, measure your basal body temperature and search for signs of cervical mucous. All this can make sex more like a chore than anything else.

"Don't focus all your sexual activity on reproduction and not fun," says Dr Hale. "Taking your temperature every morning can be stressful; you wake up and the first thing you do is remind yourself that you're struggling very hard to have a baby. You start the day on a negative note.

"Have sex around three times a week, when you feel like it, when you see the cervical mucous, but don't make sex only equal reproduction. Men can start to feel they're only having sex when his partner wants a baby and that can lead to relationship problems. So don't forget the fun!"

All material is © Mother & Baby: Making Babies

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