Some quotes from Clark's Farewell to Alms (he also covers the very high age of marriage in England as one way England held down population growth):

Fertility was also probably high among the precontact Polynesians. Sexual activity among women was early and universal. Why then was Tahiti such an apparent paradise to the visiting English sailors, rather than a society driven to the very subsistence margin of material income, as in Japan? The answer seems to be that infanticide was widely practiced...The estimates from the early nineteenth century are that between two-thirds and three-quarters of all children born were killed immediately.27...One sign of the practice of infanticide was the agreement by most visitors that there were more men than women on the islands. ...In preindustrial China and Japan the gender ratio of the population shows that there was significant female infanticide. In these Malthusian economies infanticide did raise living standards.

An additional factor driving down birth rates (and also of course driving up death rates) was the Chinese practice of female infanticide. For example, based on the imbalance between recorded male and female births an estimated 20–25 percent of girls died from infanticide in Liaoning. Evidence that the cause was conscious female infanticide comes from the association between the gender imbalance of births and other factors. When grain prices were high, more girls are missing. First children were more likely to be female than later children. The chance of a female birth being recorded for later children also declined with the numbers of female births already recorded for the family. All this suggests female infanticide that was consciously and deliberately practiced.13 ... Female infanticide meant that, while nearly all women married, almost 20 percent of men never found brides. Thus the overall birth rate per person, which determines life expectancy, was reduced. The overall birth rate for the eighteenth century is unclear from the data given in this study, but by the 1860s, when the population was stationary, it was around 35 per thousand, about the same as in preindustrial Europe, and less than in many poor countries today. Earlier and more frequent marriage than in northwestern Europe was counteracted by lower marital fertility and by female infanticide, resulting in equivalent overall fertility rates.