My big round stomach feels exactly like a ticking time bomb.

Sometime in the next three months, life as I know it will end forever. A new baby is on the way, and from experience, I know everything is about to change. Again.

This past summer lined up with my second trimester almost perfectly, so we decided to jam-pack our days with every item that’s been sitting on our “You know, we should really do X one day” list for the last couple of years.

With two boys less than 18 months apart, we have existed in survival mode ever since becoming parents. Now that the fog of babyhood was beginning to clear, we finally felt ready to be out and about again before the next forecasted storm hits later this fall.

So we went for it. We slathered ourselves in sunscreen, packed up our suitcases until over-flowing, and hit the road.

We traveled to Glacier National Park and crossed paths with mountain goats. We took the kids to splash in the water at the beach. The boys were mesmerized by their first glimpses of elephants and otters at the zoo. We flew across the country to visit my family for the first time in two years. We survived our first camping trip and watched as the moon eclipsed the sun. We picked blueberries, and the kids saw their first baseball game. My sons met their newest cousin, and for the first time, I introduced my youngest to his great-grandmother.

By the end of the summer, we were exhausted, dirty, and in possession of a slew of new family memories.

Pregnancy signals the start of a new life, not just for a child, but for the entire family. Accordingly, the old life passes away. This is not regrettable, but nevertheless, there is a definite sadness that comes when a phase in your family’s life will end.

For a new baby’s siblings, the addition can bring just as many changes as it does for parents. Most new babies come along when firstborn children are between the ages of two and three – a period already rife with significant changes and developments, often hallmarked by disruptive and noncompliant behavior.

Despite the fact that life will never return to the way it was, the research says I have little reason to worry about the effects adding a new sibling will have on my older children. A meta-analysis of studies examining the transition to siblinghood found that the period of adjustment for siblings was not as disruptive as we might initially think.

Across studies, older siblings tended to show less affection for mothers during the transition and underwent some sleep difficulty. But lasting behavior problems, including regression, seemed limited to subgroups of children, with little evidence that the transition ends up being a true crisis for most families.

The reassurance that I won’t permanently damage my older children by thrusting number three on them helps to minimize my fears about the transition. In truth, another sibling might even be good for them. Having a sibling reduces the risk of developing asthma and becoming obese. It even lowers the likelihood that your children will get divorced someday.

Experts believe there are things you can do to make the transition to life with a new baby easier on older children. Unsurprisingly, it doesn’t involve jam-packing your summer with memorable adventures. The first step is to consider timing. Between 18 months and three years of age – exactly the time frame in which most parents aim to add a new member to their family – is when older siblings have the hardest time adjusting to a new baby.

Once the new baby is on the way, regardless of the prospective age gap, parents can help their older children adjust by reading books about new babies and introducing older kids to newborns and babies, according to experts at Cornell University. Parents should also emphasize positive ways that siblings can interact, rather than just focusing on things they cannot do with the baby.

All the prep work that comes with a new child can never fully ease my anxieties, however. When I was pregnant with my first, the thought of a fundamental shift in identity, not to mention my day to day life, felt foreboding.

During my second pregnancy, I mourned the loss of our family of three and worried how I would handle being outnumbered on a day-to-day basis. In the end, my fears were proven correct.

But oh so worth it.

After the fog of the newborn days begins to settle, I know there will be a period of adjustment for all of us. During that period, there won’t be many cross-country adventures or spontaneous day-trips to the dinosaur museum. So for now, we’ll keep tackling our pre-baby bucket list and stay busy doing the things we won’t get to do again any time soon.

This time around, I have the foresight to know I won’t regret the change.