For many parents, their relationship as a couple came before their children did. Therefore, it makes sense to nurture that initial connection both before and after adding more members to the family tree.
Parenting can be a tricky endeavor, but mixing two peoples' beliefs, parenting styles, families of origin, family histories, individual struggles, and more can be a disastrous combination for family functioning if not done so carefully and with forethought. Dr. John Gottman (an expert in the field of couples therapy) performed a study in which he found 2 out of every 3 couples were unhappy in their relationships after they had children together*. So even if they were happy before expanding their family, 66% struggled after their babies arrived.
It may sound hopeless to seek happiness in your relationship if the numbers from this study are true, but I want to encourage you that there are some things you and your partner can do to stabilize your relationship both before and after you have children to increase your effectiveness as both a couple and parents or parents-to-be:
Make sure you have a solid foundation as a couple. If you have any cracks in the foundation of your relationship, these can certainly rupture even further with the added stress of having a child. To ensure your foundation is solid, you must have a mutual friendship of give and take, appreciation, affection, and kindness towards each other.
Openly communicate with each other about issues such as expectations for your growing family, how you plan to raise children, schooling options, religious upbringing, budgeting for child expenses, family vacations, etc. These conversations are crucial to discerning how you plan to raise your children together.
Spend alone time with each other regularly. Go on dates and continue appreciating the things you love about him/her. Make sure you verbalize your love for your partner and show it in his/her specific love language. If you already have children, don't think this isn't important! Make childcare arrangements so you two can spend this precious time together.
Be proactive and seek couples therapy if you begin noticing any red flags such as resentment, bitterness, exhaustion, poor communication, or frustration. These are often precursors to unhappy relationships that can end in emotional detachment, extramarital relationships/affairs, separation, or divorce.
Being both a couple and parents together is a tough journey. It will have ups and downs and at least a disagreement or two, but the payoff can be worth it if you both decide to work for it together. Nothing worth having comes easy, but with your dedication, compromise, and love, it can be more manageable.
* Source information from And Baby Makes Three: The Six-Step Plan for Preserving Marital Intimacy and Rekindling Romance After Baby Arrives (2007)