Contractions associated with the start of the first stage of labor occur about 10-15 minutes apart and accelerate in frequency. Braxton-Hicks contractions usually only occur 1-2 times per hour a few times per day, and they are not associated with labor. Rupture of membranes is not always associated with the start of labor. Although the strength of contractions is helpful to know, the frequency of contractions is more closely correlated with the start of labor. Although it is helpful to have an obstetric history, this does not determine if the patient is in labor.