|Season 02, Episode 25|
|Air date||May 20, 2001|
While Hal worries and argues with Lois over the possibility of her being pregnant again since she is two weeks late with her period, the two look back at the memories of their children's births, from Francis being born while Hal and Lois got married, Reese born early because Lois pushed him out because he kicked too hard, Malcolm born on the front yard because Lois had to go to the hospital and Francis locked her out of the car because he thought he would get a shot, to Dewey's birth on the backyard while it was raining because young Malcolm accidentally made chlorine gas and the house had to air out and the car keys were inside the gassy house.
During Dewey's birth, Hal was forced by Lois to tell her why he loves her. Later, Dewey, who has been listening to his parents, is happy that they are not arguing anymore, because he thought they would get a divorce. Lois is revealed not to be pregnant.
- A lot of information about the births of the boys are learned in this episode. Francis and Reese were the only two boys to be born in a hospital. Resee also kicked Lois a lot, while in her womb and caused a lot of pain when she was giving birth to him, and forced Reese to come out hours before he was intended to just to get it over with. When pregnant with Malcolm, Lois and Hal had to move out of the apartment they previously lived in and move into their current house. Malcolm was born on the front lawn because Hal was gone while Lois went into labor and Francis locked her out of the car. Dewey was born in the backyard because Malcolm had released a bunch of toxic fumes in the house and they couldn't get the keys to the car and drive to the hospital.
- Ever since Hal and Lois moved into their new house, all of their boys were born on the house property instead of the hospital. Malcolm and Dewey, as mentioned before, were born on the front and back lawn, respectively, and although it was not shown in this episode, Jamie would be born in Hal and Lois' bedroom in the episode Baby Part 2.
- It was revealed that the reason Malcolm became a genius is because while Lois was pregnant with him, Hal gave a bunch of musical learning activities to Reese about a bunch of random information. Reese completely ignored this, but Lois was present in the room most of those times, and Malcolm's brain absorbed the information, while he was still developing.
- Dewey was exposed to radioactive waves from the microwave, while Lois was pregnant with him, which is what caused him to have his weird personality.
- Lois and Hal have a pregnancy scare and assume they're having a fifth child. Although it turns out to be false in this episode, they'd receive another scare in Grandma Sues, which turned out to be true.
- Malcolm is seen acting like a genius at the age of four, playing with a chemistry set. However, Malcolm didn't know that he was a genius until the Pilot episode, which was while he was 11 years old, meaning that he would not have cared about working with chemistry at this time.
- The actor who played Malcolm's 4 year old self has brown eyes, when Malcolm's primary character has blue eyes.
- When Francis locks Lois out of the car and says "You're a liar. You're a liar", the reflection of a camera man filming the scene is seen on the back window.