What reasons can you explain the slow population growth in Europe in the 16th-17th centuries?

The main reasons were military conflicts and unsanitary living conditions in cities, which led to epidemics and high infant mortality. Part of the population simply did not live up to reproductive age, part died in wars, for example, the Thirty Years War devastated Germany in the first half of the 17th century. The population was influenced by religious wars between Catholics and Protestants, as well as by the Catholic clergy, who took a vow of celibacy and did not have a wife or children.