The Gemoro Nedorim 20b is critical of children born to a wife who is hated.
וברותי מכם המורדים והפושעים בי אמר רבי לוי אלו בני תשע מדות בני אסנ"ת משגע"ח בני אימה בני אנוסה בני שנואה
And I will purge out from among you the rebels, and them that transgress against me. R. Levi said: This refers to children belonging to the following nine categories: children of fear, of outrage, of a hated wife …..
Leah was hated. How is it then that Yaakov continued his relationship with her? See Braishis 29 (31 - 32)
31 And the Lord saw that Leah was hated, so He opened her womb; but Rachel was barren. 32 And Leah conceived and bore a son, and she named him Reuben, for she said, "Because the Lord has seen my affliction, for now my husband will love me."