But for them and an increasing number of young, middle-class Iranians who are deeply pessimistic over their country’s future, raising a child is one of the last things on their minds.

Bita, who like her husband asked for her family name to be withheld so they could speak freely, said she had had two abortions, which are illegal in Iran. “We are really serious about not having kids,” she said.

Iran’s leaders have taken notice. Worried about a steep decline in fertility rates that experts are predicting could reduce population growth to zero within 20 years, Tehran has started a broad initiative to persuade Iranian families to have more children.

Iran’s supreme leader, Ayatollah Ali Khamenei, sounded the alarm in a speech last winter, saying he was “shaking with fear” over the “dangerous issue” of population decline and warning officials to begin grappling with it now.

“After a few years, when the current young generation becomes old,” he said, “there will be no cure for that.”

Mr. Khamenei followed that up with a 14-point program, announced late last month, that health officials hope will lead to a doubling of Iran’s population, to 150 million, by 2050. Hospital delivery stays are now free, and women are allowed longer maternity leave. Reversing past policies to control population growth, the government has canceled subsidies for condoms and birth control pills and eliminated free vasectomies.

Billboards in the capital show a laughing father with five children riding a single tandem bicycle up a hill, leaving far behind an unhappy looking father with only one child. Those parents who actually produce five children are now eligible for a $1,500 bonus, not that many here are likely to be tempted.
“When I see those, I wonder, how can that father even smile?” said Hadi Najafi, 25, an unemployed professional soccer player. He said he did not have the money to marry, let alone keep up with rents increasing by 25 percent a year.
“Anybody with a lot of children is either very rich or very irresponsible,” Mr. Najafi said. “There is no other way.”

The demographic problem has also become entwined with Iran’s long-running conflict with the West over its nuclear program. One of the leading sources of Iran’s economic troubles is the series of harsh Western economic sanctions imposed in recent years to punish Tehran and to bring it to the negotiating table.

Though the population has doubled since 1979, most of the increase came in the years after the 1979 revolution, when sheer joy and hopes for a better future prompted many to have large families. The government also pushed procreation as a patriotic gesture during the bloody Iran-Iraq war, which ended in 1988 at a cost of at least 300,000 Iranian lives.

At its peak, in the years after the 1979 revolution, Iran’s birthrate was 3.6 children per couple, according to the Statistical Organization of Iran and experts, far above the replacement level of 2.1.

Fearing that the country’s economy would not be able to provide jobs for the growing number of young people — a situation with potentially explosive political repercussions — Iran’s more moderate clerics introduced a “fewer kids, better lives” campaign to bring down the birthrate.

But the number of children per couple has now dwindled to 1.3, more typical of a developed, high-income country like Germany, which is spending heavily to increase its fertility rate, now 1.4.

Paradoxically, Iran has never had more people of reproductive age. A little under 70 percent of the population of 77 million is younger than 35, with most living in or near cities and increasingly embracing urban culture. But many of them are profoundly pessimistic.

Like many young couples, Sherag, an architect, and Bita, a recent college graduate, cited a litany of problems as reasons for their dark outlook: an intrusive state and its conservative ideology, a sickly economy, political instability.

“When we go to bed we don’t even know what will happen when we wake up,” he said.
“I just don’t want to bring children into this hell,” she said.

That attitude is widespread among Tehran’s middle class. “Even with our combined incomes, my husband and I can’t afford to rent a place, so we alternate between our parents’ houses,” said Negar Mohammadi, the manager of one of Tehran’s most popular restaurants. “If I were to give up my job to have kids, how would we manage to rent a house for ourselves?”

Some women and human rights activists suspect that the drive for more children is also aimed at keeping women in what conservative clerics believe is their place, the home.

“It will make them more financially dependent on their husbands and the political system, prioritize the family’s well-being over women’s health and education and as a result of all these will make women’s mobilization much more difficult,” said Azadeh Kharazi, a sociologist.

The new campaign has had at least one immediate impact, prompting a doctor formerly specializing in vasectomies to shift to Botox injections. For years, the doctor, Nasir Ahmadi, performed at least 60 vasectomies a month. Now, in a good month, he says, he does 10.

“When the state stopped paying, people stopped coming,” he said.
At a shrine near Dr. Ahmadi’s clinic, the cleric in charge, Mojtaba Takhtipour, said economics should not be the deciding factor. Sitting behind a laptop, Mr. Takhtipour took a sip of hot tea and explained that Islam orders a quest for a perfect society.

“That means we need to increase the number of Muslims, so we also need more kids,” Mr. Takhtipour said. To those of his flock making financial arguments against having many children, he lectures on the scriptures of the faith. “We do believe that ultimately God will provide our daily bread. So go out and have kids and have faith, is what I always say.”

Although they dominate in Iran, Shiites are a minority worldwide, making up roughly 10 to 20 percent of all Muslims. Not only are the birthrates in Sunni-dominated countries much higher than those among Shiites, but so, too, are those of Sunni minorities living in Iran.

Tahereh Labbaf, the medical adviser to the Supreme Council of the Cultural Revolution, which deals with the population issue, said that the birthrate for the country’s Sunni Muslims is around four children per couple. “This is very sobering,” a conservative website, Tasnim, quoted her as saying.

Experts say that while birthrates in Iran are very low, there is no real crisis just yet. But they also say that financial incentives and faith will not by themselves reverse the population decline.

The critical factor, said Mohammad Jalal Abbasi-Shavazi, head of the demographics department at Tehran University, is the economy.

“A young and unmarried boy or girl who does not have a permanent job and relies on one-month contracts cannot dare to marry or have children,” he said, “because in that case he endangers his job security and his or her own living condition.”

The solution is simple and very complicated at the same time, he said. “We must try to create jobs, so people can feel secure and follow their plans.”

For Mr. Najafi, the professional soccer player, words like “future” and “plans” make him queasy. “We are always told how there is a bright future ahead, but we are not allowed to live now,” he said. “If only things were better in my lifetime, I would have a dozen children to share my happiness with.”