The truth about the Pill: Does it make you fat and reduce fertility?

Forty per cent of women who avoid contraception said they did so because of concerns over the health implications. Photo / iStock

Hailed as the most significant medical advancement of the 20th century, the Pill was introduced in 1961.

It released women from the fear of unwanted pregnancy and more than 50 years on, it's used by around 100 million women worldwide.

But its popularity has been marred by controversy, not just socially but health-wise too. Links to breast cancer and blood clots caused dips in usage, as have widely held beliefs in the Pill's ability to cause weight gain, infertility, headaches and mood swings.

According to the World Health Organisation, there are 15 million unwanted pregnancies a year. Some 40 per cent of women who avoid contraception said they did so because of concerns over the health implications.

So what is the truth? Below, experts bust common myths about the oral contraceptive...

CAN THE PILL MAKE IT HARDER TO GET PREGNANT?

Leila Hanna, consultant gynaecologist and Obstetrician at Queen Mary's Hospital in London says it's common for women to take a break from the Pill based on the belief that it could hinder their future chances of conception.

But Hanna told MailOnline: "There is no medical basis for this. It's an old wives tale.
The Pill is protective rather than damaging."

Because the Pill doesn't cause a build-up of hormones, there is no benefit to fertility from taking a break, notes the Family Planning Association.

In fact, the Pill treats endometriosis, a common condition which can harm a woman's fertility through scarring to pelvic organs.

Hanna says when a woman wants to start a family they should come off the Pill and start trying as soon as possible.

As soon as the Pill is stopped, fertility should return to normal, although for some women, it may take a few months for periods to become regular again.

While the Pill may assist in cases of endometriosis, it can also mask conditions linked to fertility problems.

Dr Veetha Venkat, consultant gynaecologist and director of Harley Street Fertility Clinic, says as a result, many women do not realise they are infertile until it is too late.

The symptoms of Polycystic Ovary Syndrome (PCOS) is one such condition which the Pill can be used to treat as it contains hormones to correct the imbalance.

But because it treats the symptoms - such as regulating irregular periods - it can also mask them, meaning the underlying problem is not discovered, Dr Venkat warned.

She told MailOnline: "If someone is on the Pill but they don't know they have PCOS, they can have fertility problems.

"They take the pill for the weeks and have a seven day break, and have a period. But the period is an artificial period. The bleed is due to withdrawal from the hormone.

"It is not a natural bleed which occurs after ovulation. An egg isn't being released - there is no ovulation."

Therefore, when these women stop taking contraception because they want to start a family, they find their periods become irregular, and they can't conceive.

Venkat advises women on the Pill who are concerned about underlying fertility problems to take a month off the contraception and go for a check up.

"They can have a scan and a blood test to check their hormones," she said.

DOES THE PILL MAKE WOMEN FAT?

It's one of the most common beliefs about the Pill, and there may be some truth in it, says Hanna.

"In some susceptible ladies, it can. Progesterone in the combined Pill reduces their ability to lose weight."

Dr Venkat notes obese women are often told to avoid the Pill because it may cause further weight gain.

While the hormone does have an effect on fat cells, making them larger but not increasing their numbers, most studies on the topic have found weight gain on contraceptives to be minor.

It's more that women can retain more fluid, giving the feeling of weight gain, particularly in the breasts, hips and thighs.

But different types of pill have a different balance of oestrogen and progesterone, so switching to a more progesterone-dominant type can sometimes help.

WHAT ARE THE BENEFITS AND THE RISKS

Like most contraceptives, there are pros and cons to taking the Pill. But most doctors conclude the benefits outweigh the risks.

The Pill has been linked to protecting against ovarian cancer, cancer of the womb lining, and pelvic inflammatory disease - a major cause of infertility in women.

It can also shorten periods and alleviate the normal pain levels, as well as provide relief from the symptoms of endometriosis and PCOS.

However, research suggested the drugs slightly increase the risk of breast, cervical and liver cancer, as well as strokes, heart attack and blood clots.

Bleeding in between periods, mood swings and headaches are other commonly-cited side effects.

Natika Halil, chief executive of the Family Planning Association, says for most women the benefits outweigh the risks "but it's really important to talk through the benefits and risks with a doctor or nurse".

"The Pill is just one of many contraception choices so if you're not happy with how it makes you feel, or if you just don't like taking a pill every day, there are plenty more options to choose from."

- nzherald.co.nz