From the Guidelines
Latent labor is defined as the initial phase of the first stage of childbirth, where cervical dilatation is negligible or absent, and the rate of dilatation is relatively flat, typically occurring before 3-4 centimeters of cervical dilatation. This phase is characterized by mild, irregular contractions that do not significantly dilate the cervix, and its duration can vary significantly, lasting from a few hours to several days, especially in first-time mothers 1. The latent phase ends when the rate of dilatation increases, marking the transition to the active phase of labor. It's essential to note that assessing uterine contractions, such as by palpation or using Montevideo Units, is of limited value in determining if a patient is in the active phase, as contractions inconsistently increase in intensity, frequency, and duration over the course of the first stage 1.
Some key characteristics of latent labor include:
- Mild, irregular contractions that do not significantly dilate the cervix
- Cervical dilatation typically from 0 to 3 centimeters
- Variable duration, lasting from a few hours to several days
- Ends when the rate of dilatation increases, marking the transition to the active phase of labor
Understanding latent labor is crucial for expectant mothers to recognize that early labor can be prolonged and variable, which can reduce anxiety about the timing of hospital admission. The definition of latent labor is based on the concept that the active phase of labor begins when the rate of dilatation transitions from the relatively flat slope of the latent phase to a more rapid slope, irrespective of the degree of cervical dilatation achieved 1.
From the Research
Laten Labor Definition
The latent phase of labor is defined as the period from the initiation of labor to the onset of the active phase 2. This phase is characterized by the cervix undergoing rapid remodeling, softening, and becoming more compliant, which prepares it for the more rapid dilatation that will occur during the active phase.
Key Characteristics
- The latent phase of labor extends from the initiation of labor to the onset of the active phase 2
- The cervix undergoes rapid remodeling, softening, and becomes more compliant during this phase 2
- The duration of the latent phase can only be estimated, as the margins are not always precisely identifiable 2
- The normal limit for the duration of the latent phase is approximately 20 hours in a nullipara and 14 hours in a multipara 2
Factors Associated with Prolonged Latent Phase
- Deficient prelabor or intrapartum cervical remodeling 2
- Excessive maternal analgesia or anesthesia 2
- Maternal obesity 2
- Chorioamnionitis 2
- Approximately 10% of women with a prolonged latent phase are actually in false labor, and their contractions eventually abate spontaneously 2
Management of Prolonged Latent Phase
- Augmenting uterine activity with oxytocin 2
- Providing a sedative-induced period of maternal rest 2
- Both methods are equally effective in advancing the labor to active phase dilatation 2
- Providers should have a low threshold to use safe and effective interventions to manage abnormal progression in the first stage of labor, including oxytocin, internal tocodynamometry, and amniotomy 3