Kyra Cornelius Kramer

Medieval Fertility Rates

St Catherine of Siena was born on 25 March 1347, along with a twin sister named Giovanna, and was the 23rd or 24th of her 40 year old mother’s 25 offspring. With all due respect to Saint Catherine of Siena, the super-fertility of her mother, Lapa Piagenti, is as amazing to me as any of Catherine’s mystical visions.

For one thing, contrary to the popular beliefs, that kind of astonishing fertility was rare even in an millennia of young marriages and no birth control. As David Cressy explains in his wonderful 1997 book Birth, Marriage, and Death, early-modern people didn’t typically marry as young or have as many children as the modern person thinks they did.

On average, women got married when they were 25 or 26 years old, and their grooms were typically 27 or 28 years old at the wedding (Cressy, 1997:285). Even through women may have conceived frequently, each pregnancy “had no better than a 50% chance of going to term” (Cressy, 1996:47). Pregnancy was such a chancy thing that women did not consider themselves to be truly pregnant until the fetus “quickened” – when the mother could first feel movement inside her, which typically occurs half-way through the gestation, at around 20 weeks (Cressy, 1997:45).

Quickening was crucial, because most people believed that the fetus did not receive a soul until the time when it could be felt moving (Hull, 1996:105). This understanding of ensoulment didn’t change until the nineteenth century, when Pope Pius IX proclaimed that souls entered the embryo at conception. Without a soul the fetus was not really a ‘person’. It was a homunculus, or miniature human form, growing in preparation for the advent of a soul. There was even doubt whether a fetus could be considered ‘alive’ prior to the quickening.

Over the course of their lifetime, most women had an average of six or seven pregnancies and births. That means that women who had 10, or 15, or 20 pregnancies and births were far outside the reproductive norm. A woman like Lapa Piagenti was a rarity in her own time, and astoundingly fertile. Even super-producing queens like Eleanor of Castile (16 children), Philippa of Hainault (13 children), and Charlotte of Mecklenburg-Strelitz (15 children) are cast in Lapa’s shade.

When Lapa Piagenti gave birth to her 25th and (thankfully) final child she was in her early-mid 40s. Sadly, Lapa Piagenti saw more than half of her children die in childhood or infancy, including having to see at least one of her adult daughters, Bonaventura, die in childbirth. Although much is made of her daughter Catherine’s choice to eschew the institution of marriage, I think Lapa’s heroic travails within the bonds of matrimony are more worthy of renown.