What is the main conflict in Little Earthquakes by Jennifer Weiner?

Little Earthquakes by Jennifer Weiner was published in 2005 and takes place in the present, where it follows the lives of four young women through their first pregnancies, childbirth and beyond. Three of the women, Becky, Kelly and Ayinde, meet at a pre-natal yoga class; they meet the fourth woman, Lia, in a coffee shop, where Becky recognizes her as the woman who has been watching her. The four women share the spotlight as main characters, although Lia's narration is in the first person while the rest of the women's stories are in the third person.