Spotlight on the terms used to describe various points of the birthing process.

I imagine when one is starting to research about labor and birth for the first time, it can be daunting to make sense of all the terms describing the various stages and phases. The terms tend to be used rather inconsistently, which makes things even more confusing. Phrases like first stage, latent phase, active phase, transition, second stage, and third stage have very specific definitions; however, various sources and various people often mean different things by the same term (Menard 2014). And then there is the often-neglected experience of the birthing person; including, the relevance of these terms and distinctions to the person actually having the birth.

The start of labor is the point when uterine contractions begin to change the cervix (Menard 2014). This cervical change can be softening of the cervix, thinning of the cervix, moving of the cervix forward (before labor and even in early labor, the cervix is located further back), and dilation (opening of the cervix). This start of labor is also the start of the first stage. An often neglected change that is also occurring in early labor, if it has not already, is baby getting into position and engaging (the presenting part, usually the head, moving into the inlet of the pelvis). The first stage of labor is demarcated by the beginning of cervical change and is thought to complete once the cervix is fully dilated. Please refer to the image bellow to visualize the cervix and imagine how it may change throughout your birth. Though the initial cervical change is often accompanied by irregular contractions that feel like light menstrual crams, the signs of early labor can vary. Some people are not aware of their uterine contractions until they are quite close to being completely dilated, while others have painful contractions that do not seem to change the cervix for days. Moreover, some people will have very slow cervical changes over days or even weeks before the contractions become noticeable.

Image result for pregnant uterus cervix
Anatomy of pregnancy

What all this means is that the start of labor is very variable and difficult to pinpoint and standardize. From the perspective of the birthing person, the start of mildly painful contractions is the most meaningful determination for the start of labor. This distinction may not match the clinical definition, but is nonetheless important because once the person is beginning to experience uncomfortable sensations, they start to exert energy to cope with what they are feeling. The sensations that come up for people vary widely; hence, how well someone copes at a particular point in the birthing process will be very individual.

If someone is experiencing painful contractions without detectable cervical change, this is often referred to as false labor or prodromal labor in the hospital. However, in home birth, this is seen as warmup. Same as stretching and warming up one’s body before exercise is not the actual workout, but has a positive effect on the actual workout, so is the labor warmup phase necessary for some individuals. Some people need more stretching and warmup than others; also, on some occasions the laboring person’s body may require specific preparation and perhaps some targeted positions or exercises to facilitate optimal fetal positioning. It is hard to say exactly why each pregnant parent and baby dyad has such a unique journey, but what is important to keep in mind is that all the elements have value and are required for that pair to work toward birth.

In cases where the water-bag releases but no contractions immediately follow, this is not considered labor. However, even in situations where this occurs, spontaneous labor (labor that starts on its own without induction agents) will eventually commence (ACOG 2016). Though popular in movies, the waters breaking signaling the start of labor is actually uncommon. Most people will start noticing labor contractions well before their water-bag releases.

The first stage of labor is comprised of three phases. These three phases are latent, active, and transition. Throughout the three phases, the cervix typically opens from closed to complete dilation. The reported measurements range from 0cm to 10cm, but in reality, complete dilation just means that there is no more cervix over the presenting part (which is usually the baby’s head), rather than an exact 10cm diameter. The latent phase is often referred to as early labor and starts with contractions that are beginning to change the cervix. Typically, this exact start of labor is unknown because people usually do not have their cervix examined at frequencies required to make this determination. Moreover, determining the exact start of labor is utterly unimportant.

The latent phase gives way to active phase when the rate of cervical dilation starts to increase appreciably (Menard 2014). Clinicians often site a singular cm dilation as the start of active phase for every birther; however, this is not accurate (Cohen 2015). The start of active phase occurs at a different cm dilation in different people. The currently touted 6cm dilation as the start of active labor misses people’s individuality. The research, based on which 6cm dilation began to be associated with start of active labor, actually demonstrated that by 6cm dilation, 95% of birthing people have reached the active phase (Neal 2015). Hence, the start of active phase for most birthers occurred at some point before they reached 6cm. Additionally, progressive cervical dilation would commonly be accompanied by the baby rotating and moving lower in the pelvis.

Typically, active phase for the birthing person will be signaled by an unexpected increase in intensity of contractions and a tendency to go inward, becoming less aware of the surroundings, and shifting to communication that is quite terse. It is also common for uterine contractions to increase in frequency and for the birthing person to feel each contraction longer. The contractions themselves do not typically become longer, it is just that the person starts to feel them from their onset to their resolution; instead of mostly at their peak. Ideally the birthing person would attempt not to focus on the frequency and duration of their contractions, because this pattern often does not correlate to the textbook definition of a particular phase. For the birthing individual and their support person, it is distracting and pointless to focus on contraction patterns, so please do not fixate on timing every contraction.

Transition phase occurs as the last few centimeters of the cervix move out of the baby’s way and the baby descends even lower in the pelvis, possibly starting to exert some pressure on the rectum, which may feel similar to how it feels when you need to defecate. During this phase the birthing person may second-guess their ability to carry on as the intensity increases even more and the hormonal flux shifts the emotions to doubt. In some way, this is a good place to be, as it is a signpost of being right around the corner from pushing, and pushing brings with it a sense of agency and relief. Observe the image bellow to see how the cervix dilates and the baby descends throughout labor.

Image result for pregnant uterus cervix
Cervical dilation and fetal descent

The transition is the last phase of the first stage of labor and once the person is completely dilated, the second stage begins. Though the second stage is thought of as the pushing stage, the urge to push may not instantly accompany complete dilation. It may take some time for the person to feel the urge to push after their cervix completely dilates. The opposite is also possible, one can have an overwhelming urge to push, but not be completely dilated. An urge to push is less of an urge and more of an involuntary reflex, your body will be doing it on its own. Hence, it is not just a feeling that you have to poop, but its your body seizing up and bearing down, you cannot stop it and it just feels right. If the person reaches the second stage, yet does not feel the urge to push, they can labor down (for hours if need be); essentially, waiting for the baby to descend lower and rotate the head to fit the pelvic outlet, which will typically trigger an overwhelming reflex to bear down when it is time.

Once the baby is born, the third stage begins. It completes with the birth of the placenta. It may seem unsettling not to have timelines included with the description of each stage and each phase, but that is very deliberate. What is considered an allowable amount of time for each part is not straightforward, and any mention of time intervals should be accompanied by a discussion about what those numbers are based on. Additionally, the presence or absence of specific parameters during labor is a much more meaningful assessment than just the duration of time that had lapsed. For a discussion on time in the first stage, please see the December 2018 entry.

What I hope to communicate in this blog post, is that there is a lot of variability in how individual births look and feel, and that that variation is normal. Even different births experienced by the same person are very different. Having set expectations and not allowing oneself to be open to the unexpected, will often result in unnecessary anxiety. Being accepting of the path this birth is taking and trusting one’s body, are key to a fulfilling birth.