> Longer breastfeeding suppresses ovulation and menstruation, so fertility is relatively rare. > Childbirth works better squatting. I would like to see citati

> Longer breastfeeding suppresses ovulation and menstruation, so fertility is relatively rare. > Childbirth works better squatting. I would like to see citations indicating that these statements are true to a significant degree that modern improvements are of little value. I can't even find data on maternal mortality before 1800.