Oxytocin promotes attachment

Pregnant women with higher levels of oxytocin during their first trimester bonded more strongly with their babies after they were born, according to a 2007 study in the journal Psychological Science. And compared with other women, women with higher levels throughout their pregnancy and in the first month after birth reported engaging in more behaviors — such as singing, feeding and bathing their infants in specific ways — that promoted an exclusive relationship between the two, the study found.