Leo’s mother seemed to be a naturally anxious person, so I was not surprised when she reached out to me early one evening describing contractions that were consistent with a latent labor pattern. First time mothers often need reassurance during this phase of the labor, even though they are not ready to head to the hospital and do not “need” to call. However, Leo’s mother seemed more uncomfortable than most and I worried that I was missing something, but I gave her some precautions and went about my evening. She called again around 1 am, now very uncomfortable with contractions, but still without a regular pattern to the labor. I told her to try a bath or a shower to ease her discomfort and wait and see if the contractions became more regular. If so, she was to head to the hospital.
No further call came that night, but by morning my phone was ringing again and Leo’s mother was now sounding desperate, though the contractions were still not regular. I instructed her to meet me in the office in a few hours when we opened. I hoped she was far enough along to be admitted, because she was obviously having a difficult time. When she arrived, I knew at once she was not really in active labor. She was exhausted and miserable, but not breathing through contractions or showing any other signs of active labor. When I examined her, she was only two centimeters and the baby was still high in the pelvis. I saw the frustration on both her and her husband’s face. I sent them back home with instructions to rest.
No further calls came that day, but at 2 am my phone was ringing again and she now was having mostly regular contractions. I sent her to the hospital and tried to go back to sleep, while awaiting word of her exam. Two hours later the call came in and the laborist had examined and found her to be four centimeters dilated. I hoped she would continue to progress and gave the orders for admission. By morning she was six centimeters, but still with a strange contraction pattern, where contractions would group up together and then space out sometimes for as many as ten minutes. She felt a lot of pressure with contractions, even though the baby was still high. She described it mostly as “front pressure” versus “back pressure.” She continued to work through the labor for several more hours, walking, trying different positions, and using the shower. However, nothing seemed to bring the baby down and she remained six to seven centimeters until the afternoon. We decided to try breaking her water. That seemed to increase the intensity of the contractions and improved the pattern, but the dilation did not progress. I could tell Leo’s head was not positioned correctly when I examined her, but she was so uncomfortable, it was difficult to determine exactly which way the baby was facing. She finally decided to get an epidural, too exhausted at this point to keep working through her contractions. After she was comfortable, we also started pitocin to try and help improve the pattern of the contractions. Despite all our efforts, we could not get the labor to advance and we headed into the operating room for a cesarean nearly 48 hours after her first call had come in. The Leo’s head was “cocked” to the side, having entered the pelvis with one side of the head uneven from the other and he just could not descend the way he needed to.
Leo’s birth story followed a common pattern that I have observed in many labors over the years. It is the story of labor dystocia, or stalled labor, but more importantly, it is a story of malposition. I have learned through experience to better manage it and I do not end up in the operating room as often as I did when I first entered private practice. However, I was not taught to recognize the signs of this problem or adjust my care of patients in response to malposition when I was in residency. One of my favorite attendings, without any malice, would passionately instruct us about how labor was simply a matter of the three P’s: the Passenger, the Passageway, and the Power. The passenger was the baby and, if the baby was too big, labor could not progress normally. The passageway was the woman’s pelvis and, if the pelvis was too narrow, the baby could not fit through. The power was the contractions. This was the one part of the equation we had any control over. If labor was not progressing, pitocin was solution. If labor was not progressing despite pitocin, we were taught to place an internal monitor which could determine whether or not we were giving enough pitocin. If the internal monitor measured sufficient contractions, then you knew your answer. Either the baby was too big or the mother’s pelvis was too small and neither were things you could do anything about, so there was no point in continuing and the correct course of action was always a cesarean. Our hospital’s rate of cesarean was over forty percent. This way of thinking was obviously missing something.
The first step in “managing” labor dystocia is to appropriately define it. Many providers are quick to diagnose a labor dystocia before a woman has even progressed into active labor. A woman cannot be diagnosed with a labor dystocia if she has not reached active labor and at least 6 cm of dilation. Latent labor is defined as the phase of labor when the laboring mother begins perceiving contractions, but active, predictable cervical dilation is not taking place. It is generally considered prolonged if it extends past 20 hours.1 Many patients, like Leo’s mother, have long, frustrating latent labors and, while this may be an early indicator of a malposition, it is not an indication for alarm given how frequently early malpositions self-correct. Latent labor may take a few hours or it can persist for many days. When it is prolonged, providers and patients alike find themselves resisting the urge to just “do something” in response, which often equates to medical pain relief and inductions for patients who had been hoping for a natural birth. There are certainly two ways to approach a long prodromal labor: actively or passively.
An active approach consists of trying various things, either medical or nonmedical, to “move the labor along.” Walking and staying physically active are generally recommended as a way to help labor progress in natural labor texts, though there is no evidence that maternal activity truly advances a latent labor.2 Position changes, such as side-lying or hands-and-knees (see Chapter 6), may help a woman advance by facilitating fetal rotation, if this is an underlying cause for her drawn out latent labor. Sexual intercourse has also been proposed as means to advance labor because human semen is a naturally occurring prostaglandin and synthetic prostaglandins are used to medically induce labor. So far, only one study has examined intercourse as a possible induction method and did not find increased intercourse improved outcomes; however, there was not a substantial difference in the amount of intercourse between the study and control groups and neither group was already showing signs of labor.3 Nipple stimulation, when examined as a tool for induction, has been shown to decrease the number of women who have not delivered in a 72-hour window, so it seems reasonable to suggest that this may be a valid tool to help a woman progress through a slow latent phase.4 Nipple stimulation may be performed either by hand or with a breast pump and is generally recommended to be performed for 5-minute intervals, separated by 10 minute rest periods, for up to 1 hour of duration or four pump-rest sets. Nipple stimulation may be performed as frequently as every 4 hours. There have been cases of too much stimulation of the uterus during nipple stimulation and, in one study of high-risk patients, may have even been associated with fetal harm. Therefore, caution is still advised with nipple stimulation and if contractions begin coming more frequently than every 4 minutes, it should be discontinued. Membrane sweeping, a more invasive method of labor stimulation in which a practitioner places a finger through the cervix and separates the bag of water away from the uterine wall, may also assist women in a prolonged latent labor, as this has been shown to decrease the likelihood of not being in labor within 48 hours.5 However, membrane sweeping is painful and carries a small risk of early membrane rupture, so many women wish to avoid it or only use it as a latter option. If these more natural methods do not have their intended effect, the final resort in an active approach to a prolonged latent phase is medical management and intervention. Some providers offer what is termed a “morphine rest,” where the mother is offered a systemic narcotic such as morphine or stadol, which is intended to help the mother obtain a little relief and rest, with the hope that this will advance the labor. Other providers simply offer a medical induction, usually in combination with an epidural, if a mother is struggling through early labor.
However, given that a prolonged latent phase is not a cause for concern, a passive approach is another valid and likely better alternative. While the word passive has negative connotations in our culture, what being passive really means is accepting or allowing what happens without an active response or resistance to it. In short, a passive approach goes with the flow and often in labor and life, that is just what is needed. Mothers managing a prolonged latent labor in this fashion should focus on taking time to rest, while ensuring they remain properly hydrated and nourished. Showers or long baths are often utilized to ease discomfort. Women should continue to be emotionally supported through the process by their partner, doula, or family. Too often, partners head back to work once it is determined that it is not quite “go time,” isolating a tired and uncomfortable mother who is trying to work through her prolonged early labor. Partners can help by offering massage, maintaining a calm and comforting environment for the mother to labor within, preparing meals, and offering frequent hydration. Hyperfocusing on the contraction pattern should be avoided, as this only heightens anxiety and frustration. It is nearly always clear when the labor has progressed to a more active phase, so parents do not need to fear the labor will rapidly progress without them knowing it. Distraction is a key part of this more relaxed approach. Women should be encouraged to sleep if they are able and, if they are unable, to continue through their normal daily activities as much as possible. Visiting with family or friends, watching television or a movie, “nesting” behavior such as cleaning or preparing last minute things for the baby, or reading are all activities that can help keep a mother’s attention off her contractions and decrease her anxiety and discomfort in response to them.
The most valuable contributions providers and hospital staff can make during this process are reassurance and help in understanding the signs that latent labor has progressed into active labor. This is particularly true for first-time mothers who do not know what to expect from the labor process and often overreact to early labor symptoms. Patients and families should be counseled that labor is both progressive and persistent. Throughout labor, contractions will become progressively stronger, longer, and more frequent. Productive contractions, contractions that actually dilate the cervix in a rapid and predictable way, persist despite position changes and rest. A good rule of thumb for a woman in the early labor process is if she can fall asleep, she is not in active labor. If contractions stop in a particular position, they are not active labor contractions. In addition to the contraction pattern, other signs that may alert women to further progress are the presence of bloody, mucousy birth show outside of a recent cervical examination, rectal pressure, nausea, shaking, or the release of membranes. Women should be comforted in the fact that they are not alone in experiencing difficulty with this stage of the labor, especially when it extends for a long period of time, and should never be made to feel foolish for coming to the hospital “too soon.”
Once a woman reaches the active phase of labor at approximately 6-cm dilation, dilation typically proceeds at a more predictable rate. As discussed in Chapter 5, it was previously believed that women in active labor should dilate at a rate of at least 1 cm/h. However, more recent studies demonstrate that it is perfectly normal for that rate of dilation to be as slow as 0.5 cm/h, with first-time mothers typically dilating at a slower rate than mothers who have had a previous vaginal delivery.6 A prolonged active phase, or labor dystocia, occurs when the observed rate of dilation is slower than this 0.5 cm/h and a stalled labor, or arrest of labor, is defined as no progressive dilation for more than 2 hours.
Active phase dystocia is the most commonly observed labor abnormality and reason for deviation from a natural labor plan to one that involves epidurals, pitocin use, and cesarean sections.7 In traditional obstetrics thinking, within the active management of labor framework, labor is viewed as a simple matter of physics. Adequate force is able to move an appropriately sized object through and adequate space: the power, the passenger, and the passageway. In this case, strong and frequent contractions are able to deliver a baby, presuming the baby is not too big or the maternal pelvis too small. Hence, all recommendations in the medical literature for management of labor dystocia center around how much power, or pitocin, should be given, how sufficient contractions are demonstrated, as measured by an internal pressure catheter in Montevideo units, and for how long it is advisable to wait in the setting of appropriate contraction strength before declaring that a vaginal delivery is impossible and proceeding with a cesarean. It is a very limited view of dystocia and, unsurprisingly, it offers a narrow range of remedies for the problem.
For a woman who presents in active labor, it is actually highly unlikely that suddenly her contractions will become inadequate to continue advancing her labor, unless something else alters the course of her labor, such as bed restriction, IV fluid administration, or an epidural. Absolute cephalopelvic disproportion (CPD), where the size of the baby’s head simply will not fit through the woman’s pelvis, regardless of position, is a contentious diagnosis to make clinically, in that it really cannot be proven, even with radiological studies.8 Often women are told they are likely to have CPD, prior to labor, on the basis of a pelvic examination that reveals a prominent sacrum, a narrow pelvic arch, or an android or platypelloid pelvis. Women may also be warned about CPD if they are short in stature or short waisted, have a tall partner, are obese, or simply if their baby is suspected to be large.
While short stature and more narrow pelvis types are correlated with higher rates of labor dystocia and cesarean for CPD, the majority of women can have a vaginal delivery even when one of these risk factors are present.9 This is because the pelvis is not a static structure. The bones of the pelvis are joined with connective tissue that can relax and stretch, increasing the dimensions of the pelvis by up to 20%, depending on maternal position. The size of a baby’s head is also not constant. The fetal head has the ability to mold and elongate due to the presence of unfused sutures between the bones of the skull, facilitating passage through the narrow pelvic outlet. Several studies have shown that over 60% of patients who were diagnosed as having absolute CPD in a prior pregnancy and were offered a trial of labor in their second pregnancy went on to have a successful vaginal delivery, certainly calling into question how often absolute CPD actually occurs.10,11
More often than not, when dystocia occurs in a naturally laboring woman, it is due to relative CPD, meaning the baby’s head cannot fit through the pelvis in the position in which it is presenting. Malpositions are difficult to diagnose using digital examination, with digital exams having been shown to be inaccurate up to 65% of the time when assessing fetal head position, and few providers utilize more reliable ultrasound assessments of position in routine practice.12,13 Ideally, the baby should enter the pelvis in an occiput anterior (OA) position, with its head facing the maternal back. The most common malpositions encountered in labor are occiput posterior (OP), known as a sunny-side up baby where the head is facing out toward the mother’s front, or occiput transverse (OT), where the head is facing one of the mother’s hips. It is not uncommon for babies to enter labor in either one of these less ideal positions and the majority will simply rotate during the labor process, leading some to theorize that persistence of these positions are not actually malpositions, but rather intrapartum malrotations. Regardless of semantics, persistence of OP or OT positions into the later part of active labor or the second pushing stage of labor inhibits the proper flexion and extension of the fetal head as it moves under the mother’s pubic bone, which is necessary for proper decent. Malpositions require the maternal pelvis to accommodate a much larger diameter of the fetal head, which is unable to mold and elongate in the usual fashion.
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