A gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people.Mutations range in size; they can affect anywhere from a single DNA building block (base pair) to a large segment of a chromosome that includes multiple genes. gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people.
True labor contractions last more than 30 seconds at the onset and get progressively longer, up to 60 seconds, whereas false labor contractions vary in length and intensity.
1 How long it lasts: 3 to 6 hours for a first-time mom; 1 to 3 hours for subsequent labors. 2  If you've taken Pitocin, a drug that induces contractions, this phase may go more quickly, but if you've had an epidural, things can slow down.