Maintaining and growing relationships with your partner, and teaching your child how to build their own relationships is really important for mental health and self-esteem. From pregnancy to the time your child is an adult you will see yourself and them change and keeping up good relationship habits and managing social skills will make sure that your relationship with your child and your partner, as well as their relationships with other people stay healthy.
When parents are separated, it’s still important to try and keep the relationship with them positive. Your child learns from you, and their ideas of healthy relationships will come from other relationships they see.