Surely you are joking... Miscarriages, even a century ago, claimed so many women. You would be lucky to live past your third, much less your tenth!
Without some network to provided for her (either by her family, or the village, or her mate, all of which are strongly effected by status), the likelihood of surviving a pregnancy becomes much lower.
Women couldn't just flip a switch and get pregnant to satisfy a biological urge. Pregnancy represents both an enormous investment in time, effort, and energy, and a gamble on life. Status structure reflects this.