If the sidewalks seem less clogged with Bugaboo strollers these days and you can't remember the last time you had to diaper a doll at a baby shower, it's not your imagination or fuzzy memory. Birth rates in the U.S. fell 2% in 2008, the biggest drop in nearly four decades, and that trend is expected to continue. A new study out Sept. 23 from the Guttmacher Institute suggests that the timing is not a coincidence; the recession may be to blame, as women factor economic anxieties into their decision about having children. Those worries are understandable. All the adorable photos now taking over your friends' Facebook pages can't mask the fact that kids are expensive. TIME's Nancy Gibbs recently estimated that it costs parents an average of $221,000 to raise a child to age 17. That large economic investment is one reason that birth rates have historically fluctuated with the economy — the U.S. experienced significant dips during the Great Depression and in the inflationary years of the 1970s.(Read "The Economic Benefits of Marriage: A Closing Gap.") Researchers at the Guttmacher Institute, a research nonprofit that focuses on reproductive health, surveyed 947 women between the ages of 18 and 34 who have household incomes under $75,000. More than 4 in 10 said the economy was affecting their decision about having children. The women reported waiting to get pregnant later than they had planned, deciding to have fewer children or opting for medical sterilization to prevent future pregnancies. A majority of the women surveyed (52%) said their financial situation had worsened in the past year, and they were most likely to make their family-planning decisions on the basis of economic concerns. (See photos of Pregnant-Belly Art) For these economically vulnerable women, the cost of having a baby would further shake their already precarious financial footing. Three-quarters of them (77%) agreed with the statement "With the economy the way it is, I can't afford to have a baby right now." And while the cost of raising a child may already be prohibitive for many, others fear the consequences of pregnancy in an unstable job market. Close to half of the women who are currently employed said they worried about taking time off from work for medical appointments, which increase in frequency throughout pregnancy. The existing employer-based health-insurance system exacerbates concerns for women who are considering having a child. If a woman is unsure whether she will have the same job in nine months, she may be hesitant to get pregnant for fear of losing or switching insurance plans. Federal law prevents group plans from defining pregnancy as a pre-existing condition, but individual plans vary and can end up charging women tens of thousands of dollars for a delivery. (Read "The Risks [and Rewards] of Pills and Pregnancy.") But while anxiety about the economy has led some women to become more strict about their birth control use, the recession has forced others to take more risk. Among women who use birth control pills, 18% reported skipping pills, skipping months or waiting to get a prescription filled in order to save money. All of these practices render ineffective the Pill's use as a contraceptive, and yet a quarter of women who are financially worse off than last year reported inconsistent use of birth control. At the same time, national abortion rates continue to fall, and are now at a 30-year low. One consequence of these makeshift financial strategies, says Sharon Camp, president of the Guttmacher Institute, could be a further widening of the birth rate between wealthier women and the working poor. "Those who can afford better methods with a big upfront cost — like IUDs or vasectomies — may see pregnancy rates continue to fall," says Camp. "But among lower-income women, a third of them are saying that they can't afford the contraception they'd like to use. They're relying on less effective, over-the-counter methods. We could likely see an increase for them in unintended pregnancies."

如果现在人行道上的婴儿车不再拥堵，并且你想不起你最后一次在送礼会上为婴儿抱尿布的情景，这不是你的想象力或者记忆力出了问题。2008年美国的婴儿出生率出现了最近40年中最大的降幅，下降了2%，而且这种趋势被认为仍将持续。古特马赫研究所9月23日的最新研究成果表明，出生率下降并非巧合，经济萧条才是主要原因。因为女性决定生育时会担忧经济状况。 那些担心是可以理解的。朋友们的 Facebook相册里可爱的照片不能掩盖养育后代是花销巨大的这一事实。时代周刊的Nancy Gibbs最近做了一项估算，父母养育一个孩子直到17岁平均需花费221,000美元。美国在大萧条时期和上世纪70年代的通货膨胀时期经历了大幅的新生人口率下降，养育后代这笔巨大的经济投入成为出生率随着经济情况历史性波动的一个原因。（参考“婚姻的经济利益：一个正在缩短的差距”） 古特马赫研究所的研究者们在一项非盈利性研究中着重关注生殖健康，通过观察947名年龄在18到34岁之间家庭收入在75,000美元以下的女性，其中超过 40%的受访者表示经济情况影响她们做出要孩子的决定。她们表示要打定主意少生孩子或者靠避孕药避免怀孕，待到有了计划之后才会怀孕。大多数受访女性（52%）表示去年她们的金融情况不容乐观，并且她们会在考虑经济情况的基础上做出家庭计划的决定。（见“隆起的腹部艺术”照片） 对于这些脆弱的精打细算的女人们来说，要一个孩子的成本会令她们本已不稳固的金融基础雪上加霜。她们中的四分之三（77%）同意“照目前的经济状况，我目前负担不起再生一个孩子”的说法。当养育一个孩子的成本高的已经令许多人望而却步的时候，另有一些人因为身处不稳定的工作环境，也对怀孕这一结果心有余悸。在目前的职场女性当中接近半数表示她们担心在怀孕期间要越来越经常地在工作期间请假到医院去检查身体。 现存的以雇主为基础的健康保险系统加剧了正在考虑生育的妇女的问题。如果一名女性不确定在未来九个月内她会不会做同一份工作，她可能会对怀孕犹豫不决，因为她害怕丢失或更换保险计划。联邦法律禁止以确定怀孕为前提条件的集体保险计划，但是个人保险计划不同并且会以收取妇女们数万美元的分娩费用作为结尾。 但是对经济的焦虑已经让一些女性更加严格的使用节育手段。在经济衰退中不严格节育的女性，如果怀孕就会被迫承担更大的风险。在使用避孕药的女性中间，18% 曾经停止服用，暂停几个月或者借助医生处方以便省钱。这些做法都削减了避孕药的作用。四分之一的女性因为收入状况大不如前，不能坚持使用节育措施。与此同时，全国流产率持续下降，已经到达三十年来最低。 古特马赫研究所的所长莎朗坎普说这些金融问题的权宜之计的一个可能结果就是富有女性和收入不高的工薪族女性的生产率差距进一步被拉大。“那些可以承担较昂贵节育方法（例如精管切除术）的人们，能看到他们的怀孕率持续下降，但是那些较低收入的女性，她们中的三分之一认为他们不能负担他们所希望的避孕措施。她们正在采用效率较低的方法。我们可能会看到她们中越来越多的人无意识的怀孕。”坎普说。