One out of every 10 couples in Nigeria uses contraception - but in Jigawa, a rural state in the north I visited, the rate is 1%, although services are now being provided here that did not exist four years ago.
Evidence published in The Lancet suggests providing more contraception around the world could save 100,000 lives every year, by stopping many women from dying in childbirth.
And a big international meeting in London this week will give details of new funding for contraception in developing countries.
The event has been jointly organised by the British government and the Bill and Melinda Gates Foundation.
Nigeria will be among the countries on the agenda - its population is 167 million and rising.
I found family-planning services there are starting from a low base, and need to be planned as a part of many other essential health needs.
Women holding babies stood patiently in a queue for a malnutrition clinic at a basic health centre, consisting of two huts, in Katika village.
Zaliha Alhassan, 35, has had eight children and two miscarriages.
Speaking through a translator, she told me: "I am glad to have been given a contraceptive jab. It lasts three months."
Hadiza Damina has also had the contraceptive injection. She seems relieved to have a break from pregnancy - after three children and also six miscarriages.
She said: "I want to stop giving birth because of the difficulties I encounter each time. It's not easy, it's been very sorrowful for me."
Both women live in mud-built homes near the clinic. Jigawa is a traditional, conservative and mainly Muslim society.
British aid worth £3m, from the UK's Department for International Development (DfID), boosts Nigerian government funds in paying for the injections and other contraceptives.
It is a subtle relationship, in which the Africans are expected to do the running, by starting services and generating projects.
The donor then steps in to support schemes - giving advice on training midwives, for example - and carefully scrutinise progress. Even talking about "family planning" is sensitive in Nigeria though.
Jigawa's health commissioner, Hassana Adamu, said: "There's a widely believed notion that God provides for whomever he creates, so this means some people think there's no reason to limit the size of your family.
"So we call the programmes 'child spacing' - and explain it's about women spacing out their births, so their bodies have ample time to recover and prepare for the next pregnancy."
While I was in Nigeria, remarks from President Goodluck Jonathan that alluded to the prospect of introducing a law on birth control caused a storm.
The government insisted he had been misquoted. But ministers do acknowledge the population cannot keep growing at 3% a year without economic growth that reaches everyone.
Mike Egboh runs a programme called Paths 2, which is trying to improve how health systems in Nigeria function using schemes such as repairing hospitals.
Mr Egboh's motivation is highly personal - his own mother died in labour during her 11th pregnancy.
He told me: "Many of us here in Africa were not planned children.
"I've seen women being wheeled out of the labour room dead. I stayed at a hospital one day - and within three hours, there were five dead bodies. Five. I'm not kidding - I was there."
Paths 2's state team leader in Jigawa, Abubakar Kende, said: "Many of these women cannot afford to continue bearing children. They are looking for a way out.
"They used to lack the information - but now we're providing it and the contraceptive commodities are there, free of charge. So I feel the barriers will soon be overcome."
The International Development Secretary, Andrew Mitchell, said: "It is a shocking fact that pregnancy can be a death sentence for many girls and women in the developing world.
"What is all the more devastating is that many of these pregnancies were unintended.
"That is why the British government and the Gates Foundation are hosting a summit in London on 11 July, which we hope will cut in half the number of girls and women, who want contraception to delay or space their pregnancies but are unable to access it."