East Timor's Government is deciding whether to adopt a controversial new policy that would ban contraceptives for anyone except married couples.

A draft family-planning policy before the Government in Dili would force unmarried women and girls to use only natural methods which many argue increase the risks of unwanted pregnancy, particularly among young and poorly educated women.

In a country where teenage pregnancy rates are already high, women's groups are alarmed at the potential impact if the policy is adopted.

Teenage girls in East Timor have a one-in-four chance of giving birth by the time they are 19.

The devoutly Catholic country has one of the highest fertility rates in the world at 5.6 — meaning the average Timorese woman will have between five and six children.

And teenage pregnancy rates mean many children are born to a mother who herself is still an adolescent.

"About one out of five girls are married actually before the age of 18. They're marrying young and 50 per cent of them already have a child by the time they're 20," said John Pile, who heads the United Nations Population Fund (UNPF) in Dili.

"Frequently it's pregnancy followed by marriage and then the child. And that seems to be much more the issue than marriage then pregnant and child."

Women's groups fear natural method risky

The policy would ban contraceptives for anyone but married couples.

Unmarried women and teenage girls would instead be directed to use the Billings method, where a woman uses her own monthly cycle to calculate which days are safe to have unprotected sex.

"The new family planning program will reduce the incidence of pregnancy and … reduce the risk of abortions," the program states, citing God and the Catholic church in its recommendations.

"The natural Billings method allows for the dignification of human life and respect for cultural and religious values such as God's creation."

East Timor has high teenage pregnancy rates and one of the highest fertility rates in the world. ( Flickr: Kate Dixon )

But women's groups have said the Billings method is highly risky, given how little most Timorese girls are taught about sex or pregnancy.

Some girls and young women do not even know they are pregnant until many months in.

A report published earlier this year cited one young woman who only discovered she was pregnant at seven months when she "felt something moving inside my tummy".

Although contraceptives are not always readily accessible, women's groups and the UN fear an outright ban would force even more girls into early marriage.

"Because of teenage pregnancy they will drop out from school," said Fatima Soares, the women and girls participation program manager at Plan International.

"They will not access education any more. They will stay at home, they will take care of their children. And they will do domestic work."

Cultural attitudes in East Timor difficult for young women

The report, jointly produced by Plan and the UNFPA, identified teenage pregnancy rates as a major contributor to maternal death, infant mortality and malnutrition.

"Complications linked to pregnancy and childbirth comprise the second cause of death for 15 to 19-year-old girls globally," it said.

"In addition, the mortality rate for children born to teenage girls is much higher, with babies more likely to have a low birth weight, and facing a greater risk of malnourishment and underdevelopment.

"These results are also reflected in data from Timor-Leste, which shows that teenage mothers aged 15 to 19 years die nearly twice as much as mothers aged 20 to 24 years."

Mr Pile said cultural attitudes in East Timor made it difficult for girls to continue their education if they fall pregnant.

"Even though there's a policy to have them continue schooling, frequently they're pulled out of school — either by their family or frequently the schools themselves feel they're protecting the girl by not exposing her to the school environment where she might be ostracised for falling pregnant," Mr Pile said.

"So the impact is both: girls are getting pregnant and it limits their ability to continue their education."

Attitudes towards dating also make it difficult for girls to control their sexuality.

"In East Timor there is no culture of dating," he said.

"There is not a safe environment for adolescent boys and girls to develop friendships — platonic or romantic — so if you become friends it's frequently perceived that it has to be romantic, and pressured into a setting of making it revolve around sexuality.

A draft family planning policy would force unmarried women and girls to use only natural methods. ( Supplied: PLAN International )

"Girls don't have a lot of agency to negotiate. You see women and girls frequently talked into having sex with their partner, as in 'if you truly love me you should be able to show it'.

"And often it's not so much coercion, but [women] accept that because they also perceive that's their future. From their perspective they'd like to be married, have a family. It's their goal."

UN and young women raising concerns about policy

The policy was promoted by former health minister Maria do Ceu Sarmento, a devout Catholic who is no longer in government and could not be contacted by the ABC.

The United Nations has lobbied the new Government to abandon the policy. It said banning contraceptives for unmarried women would contravene basic human rights.

Young women too have said the policy must be changed.

"Young people should have access to contraception because young people are the most affected and have the biggest problems if they fall pregnant," 19-year-old Elfia Sarmento said.

Odelia da Luz Vargas, 18, said girls also needed better sex education.

Odelia, 18, and Elfia, 19, are arguing against the newly proposed policy. ( Supplied: PLAN International )

"Many girls my age are already married. The first reason is that they don't have access to information," she said.

"Students and young people need to get a better understanding of sexual reproductive health education."

The ABC sought comment from the Timorese Government, but there was no response. The current Health Minister, and former prime minister, Rui de Araujo, was uncontactable.

But it is understood the new government elected in July is reviewing the policy and has made some changes.

However, it is yet to reveal whether it will adopt or scrap the ban on contraceptives for unmarried women.