Amid all the negative publicity about the rising rate of Caesarean sections, it is easy to lose sight of the fact that it is often a life-saving operation. Literally tens of thousands, and perhaps hundreds of thousands, of babies and mothers are saved each year. The Caesarean section is probably the single most important factor responsible for the dramatically lower rates of maternal and neonatal deaths since the beginning of this century (and medical advances have made it safer now than ever before).
Nonetheless, it is possible to have too much of a good thing. The odds are as high as 1 in 5 that Caesarean section will be recommended to you. How will you know if it is the right procedure for your situation? How can you avoid having an unnecessary Caesarean section? The first step toward answering both questions is to understand exactly what a Caesarean section is-and when it is recommended.
Caesarean section is the operation in which a baby is delivered through an incision in the abdomen, rather than through the vagina. It is named after Julius Caesar; as legend has it, he was born this way. It is often referred to as C-section.
The most common reason for a C-section is cephalopelvic disproportion (CPD), which is just a complicated way of saying that the baby's head does not fit through the mother's pelvis. This can happen for a variety of reasons, including an unusually large baby, an unusually small pelvis, or an unusual position of the baby, such as occiput posterior presentation. CPD is a diagnosis that can be made only during labor. If the labor fails to progress beyond a certain point, despite good contractions for at least two hours (often strengthened by Pitocin), it is unlikely that the baby is going to fit.
You might imagine that every labor would automatically progress to 10 cm. dilation and that the difficulty would arise during the attempt to push the baby out. However, in some way that we do not yet understand, the uterus senses that the baby cannot fit properly. Cervical dilation may stop several centimeters before full dilation, and no further progress will be made despite many additional hours of labor. Whether progress stops in the active phase or during pushing, it is a sign that C-section may be necessary. Without full dilation of the cervix, C-section is the only option; if progress stops during pushing, forceps or vacuum extraction may be considered if the baby's head is low enough.
There are undoubtedly some unnecessary C-sections that are done presumably because of CPD. It is important for the practitioner to wait until the active phase before making the decision that the baby cannot fit. In the latent, or first, phase of labor, progress may be extremely slow and may take many hours; this is a sign that labor hasn't really started efficiently, not a sign that the baby doesn't fit. As a general rule, the diagnosis of CPD should not be made before approximately 5 cm. dilation.
Another contributing factor to unnecessary C-sections for CPD is pain relief that is given too early. Short-acting narcotics and epidural anesthesia sometimes interfere with the progress of labor before the active phase begins. If you are anxious to avoid a C-section, it is best to wait until 4-5 cm. dilation before asking for pain relief.
Additionally, a large number of C-sections are done for breech presentation. As discussed in detail in Chapters 12, 26, and 27, vaginal delivery from the breech presentation involves much greater risk than vaginal delivery head first. If attempts to turn the baby have been unsuccessful, C-section is often recommended. In this situation, most women, wishing to minimize any risk to the baby, select C-section as the preferred delivery option. However, most C-sections done for breech presentation could be considered unnecessary in the sense that vaginal delivery of most breech babies turns out fine. Unfortunately, at present we have no way of determining with any certainty which breech babies will be permanently injured by vaginal delivery.
Another common reason for C-section deliveries, and probably the most controversial, is fetal distress. These C-sections are performed because the practitioner suspects that the baby is being deprived of oxygen. The diagnosis is usually made by analyzing the fetal heart rate tracing, although other factors such as moderate to thick meconium in the amniotic fluid can raise suspicions or lend support to the diagnosis. More sophisticated tests, such as fetal scalp sampling (in which a tiny sample of the baby's blood is taken from its scalp and tested for oxygen content) may be used to confirm the diagnosis of fetal distress, especially if there is an element of doubt about the meaning of the heart rate tracing.
A lot of C-sections done for fetal distress are probably unnecessary. Many babies who experience even prolonged oxygen deprivation during labor probably will sustain no permanent brain damage. Unfortunately, it is very difficult to determine which babies are in danger of suffering irreparable damage. Obviously, no obstetrician wants to wait until the damage is done; at that point, the diagnosis is easy-but by then it's too late. Caesarean section should be performed while the baby is still healthy if fetal distress is strongly suspected. Yet when that healthy baby is delivered, it is often impossible to determine if the obstetrician acted too quickly, or acted prudently to avoid permanent injury.
In most situations, it is no longer considered necessary to have a repeat C-section if you had one in a previous delivery, provided that the incision made in the uterus was transverse-that is, made horizontally across the uterus. Vaginal birth after a previous C-section is commonly referred to by the acronym VBAC. Women have the option of requesting a repeat C-section, and many do, especially if they had a particularly difficult first labor. However, if you had a vertical incision on your uterus the first time, C-section will be recommended. Vertical incisions are considered less likely to withstand the stress and strain of contractions.
There are also some uncommon situations in which C-section is always necessary and appropriate. These include placenta previa (when the placenta blocks the cervix), heavy bleeding and cord prolapse (when the umbilical cord falls out before the baby is delivered). In these cases, C-section is undoubtedly a life-saving procedure.