Abstract After decades of fertility postponement, we investigate recent changes in late parenthood across low‐fertility countries in the light of observations from the past. We use long series of age‐specific fertility rates from the Human Fertility Database (1950–2016) for women, and new data covering the period 1990–2016 for men. In 1950, the contribution of births at age 40 and over to female fertility rates ranged from 2.5 to 9 percent, but then fell sharply until the 1980s. From the 1990s, however, the prevalence of late first births increased rapidly, especially so in countries where it was initially lowest. This has produced a late fertility rebound in the last two decades, occurring much faster for women than for men. Comparisons between recent and past extremely late (age 48+) fertility levels confirm that people are now challenging the natural fertility barriers, particularly for a first child.

中文翻译：

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最晚受孕？低生育率国家晚育率的下降和复苏


摘要 经过几十年的生育推迟，我们根据过去的观察调查了低生育率国家晚期生育的最新变化。我们使用人类生育力数据库（1950-2016）中女性生育率的长系列特定年龄生育率，以及涵盖 1990-2016 年期间男性的新数据。 1950年，40岁及以上生育对女性生育率的贡献为2.5%至9%，但随后急剧下降，直到20世纪80年代。然而，从 20 世纪 90 年代起，晚一胎的发生率迅速上升，尤其是在最初生育率最低的国家。这导致过去二十年生育率出现较晚的反弹，女性的反弹速度比男性快得多。最近和过去极晚（48 岁以上）生育水平的比较证实，人们现在正在挑战自然生育障碍，特别是对于第一个孩子。