This section will cover everything related to birth. It begins with a discussion on conception and fetal development, including fetal circulation. Maternal changes during pregnancy will be discussed along with medical issues that can go along with these changes. Next will be preterm emergencies associated with pregnancy. This section will then conclude with a review of the stages of labor during normal deliveries. Since the APGAR Score is determined before the conclusion of the third stage of labor, it is included in this section as part of the continuum of perinatal care.
As the ovum passes through the fallopian tubes, if it encounters sperm within approximately 24 hours of ovulation, fertilization may occur. Fertilization of the ovum usually occurs in a fallopian tube. After fertilization, the fertilized ovum, now called a zygote, continues to travel down the fallopian tube and implants in the endometrial lining somewhere within the uterus where it will grow and develop into an embryo and then into a fetus. Implantation happens about a week after fertilization.
By the time of implantation, the zygote has undergone multiple rounds of cellular division and is now called a blastocyst. What was once a single cell, by the time of implantation has features that will become the fetus, placenta, and amniotic sac. Implantation can cause some spotty painless bleeding that may be alarming to the mother who does not yet know she is pregnant or dismissed easily as early, light menstruation.
Implantation causes a cascade of changes in the mother as well. Shortly after implantation, the union of the blastocyst with the endometrial lining signals the lining to begin to release hCG, which simulates the corpus luteum in the ovary to continue to release progesterone. Progesterone is responsible for maintaining the endometrial lining throughout pregnancy. Within 10 days from implantation (<3 weeks after conception), the embryo has developed a placenta, an umbilical cord, and an amniotic sac, and the rudiments of a heart have already begun to beat rhythmically.
By the end of the 3rd week of pregnancy, the circulatory system is complete with some vasculature, a heart, and red blood cells. The neurological system is beginning to develop, and distinct areas of the brain can be differentiated. By the end of the 4th week, extensive folding of a previously basically flat embryo has given rise to the cranial vault, spinal cord, and the chest and abdominal cavities. The digestive tract also begins to develop, oriented by the location of the brain. The brain is essentially complete with all the distinct features it will have in simply smaller versions; growth will continue in the brain to enlarge itself for several weeks to come. Limb buds also begin to appear once the spinal cord is complete.
Over the next several weeks, development will continue at an alarming rate. The digestive system with all the accessory organs is visible and essentially complete by the end of the 6th week. The eyes have begun to take shape and orient themselves near the brain. The kidneys will be completely formed and functioning by the end of the 6th week, and glucagon is being produced by the fetal pancreas. From about the 8th week on, the structures critical to life outside the womb have developed, and the musculoskeletal system continues to develop bone, cartilage, tendons, and muscles. The fetus will not be capable of survival outside the womb for about another 4 months, however, because it is still too small. After the 28th week of gestation, the fetus is said to be viable if it is born prematurely, although it still requires extensive care.
The infant floats in a watery fluid called amniotic fluid or amnion, which is contained within the amniotic sac and serves to provide an essentially weightless environment in which the infant will develop. Later on, the fetus will consume the amnion and pass wastes into the fluid, so it also serves an excretory function.
The umbilical cord and placenta connect the fetus to the mother. The fetus gets all its O2 and nourishment from the mother via these 2 structures. Nearly everything the mother consumes can pass across the placental barrier, including sugar, protein, water, alcohol, and most illicit and prescription drugs. Though drugs of any kind are a concern throughout pregnancy, they are most dangerous during the rapid development that occurs between the 3rd and 8th weeks. During these weeks in particular, drugs can interfere with proper formation of the circulatory and nervous systems in particular but also the digestive and endocrine systems.
The fetal circulation is different from that of the independent person. The veins carry oxygenated blood away from the placenta and toward the fetus, whereas the arteries carry deoxygenated blood toward the placenta and away from the fetus. A way to remember this is that the Arteries carry blood Away from the fetus and therefore are Anoxic (without O2).
Within the fetus, circulatory differences also are present. Because the lungs of the fetus are not responsible for oxygenation of the blood until after birth, it is energetically favorable to the newborn to largely bypass the pulmonary circuit. Blood that enters the right atrium of the heart has already been oxygenated from the placenta and can pass as expected into the right ventricle, but it also can pass through the foramen ovale directly into the left atrium. The blood that goes directly into the left atrium is then eventually pumped to the rest of the body through the aorta as normal.
The blood that entered the right ventricle also has 2 options. Some blood will, in fact, go to the lungs to nourish the cells of the lungs themselves, but some blood will pass from the pulmonary artery directly into the aorta through the ductus arteriosus. This bypasses the pulmonary circuit and helps deliver the most blood to the body as possible with each beat. Within 30 minutes after the neonate takes its first breath after delivery, the ductus arteriosus and foramen ovale will close, establishing adult circulatory pathways. Pay particular attention to the areas that blood has a choice of direction.
The gravid female also experiences many physiologic and anatomic changes during pregnancy to be able to carry and metabolically support the growing fetus. Changes occur in the circulatory system, the urinary system, and the digestive system.
Blood volume increases by approximately 50% during the course of pregnancy, increasing the volume from about 4.5 L to approximately 7 L. This increase is necessary to meet the perfusion needs of the fetus as well as maintain the perfusion of all maternal organs, particularly the kidneys. Furthermore, this prepares the mother for delivery, where the mother can lose in excess of 500 mL of blood during a normal spontaneous vaginal delivery (NSVD) and sometimes as much as 1,000 mL during a cesarean section. This excess volume allows for an autotransfusion of blood from the uterus as it contracts back to maternal circulation.
Red and white blood cell counts increase during pregnancy. The red blood cell count increases by nearly 35%, which is why most women take prenatal vitamins or, more recently, simply an iron-containing multivitamin. The increased rate of erythropoiesis makes an iron supplement essential; without it, pregnant women can suffer from pregnancy-related iron-deficiency anemia. White blood cell counts typically triple during the course of the pregnancy.
The maternal heart actually increases in size to be able to handle the polycythemia and increased circulating volume by anywhere from 10% to 15%. This increases overall cardiac output about 40% from about the 22nd week of pregnancy through the end. Helping increase the cardiac output, the heart rate also increases to a new normal resting rate about 20 beats per minute higher than before the mother was pregnant.
The respiratory system experiences stress as well and for a variety of reasons. First, a lot more blood is circulating that needs to be oxygenated. Second, the mother’s overall O2 demand has increased to meet her increased metabolism as well as the fat metabolism of the developing fetus. Third, as the fetus develops and the uterine fundus pushes superiorly, it will push the abdominal contents against the diaphragm. This is initially compensated, limiting the ability of the mother to expand her chest cavity. This results in an overall decrease to the tidal volume in late stages; however, early on, the tidal volume and minute volume increase, each by as much as 50%.
The kidneys increase in size by up to 30%, and the ureters can actually increase in diameter to accommodate the increase in urinary output. Consequently, the mother increases the amount of urinary output volume, therefore increasing the frequency of urination. Complicating the increased urine volume produced is a marked decrease in the volume of the urinary bladder. This is why pregnant women feel as if they are constantly urinating!
The GI system experiences decreased motility because of increased progesterone levels, which can lead to heartburn and belching. It also can exacerbate vomiting if food stays in the stomach for too long. The weight of the fundus on the lower intestines, coupled with decreased overall motility, can lead to constipation. The combined metabolism of the mother to accommodate the weight gain and structural changes as well as provide for the fetus’s metabolic needs often can lead to an increase in carbohydrate intake. Women can become diabetic during pregnancy, called gestational diabetes, as a combined result of increased carbohydrate intake and cellular decline in insulin sensitivity despite an increase in insulin production in the pancreas.
First, let’s clarify some pregnancy-specific terminology.
Using this GPAL shorthand method, a patient who was currently pregnant with 1 child and had viable twins from a previous pregnancy with no prior elective abortions would be G:2, P:2, A:0, L:2. Once this hypothetical mother has the child from her current pregnancy, the numbers would change to G:2, P:3, A:0, L:3. Some physicians may break down the parity number further to clarify term and preterm. Preterm would be any infant born prior to 36 weeks of gestation.
The history of the pregnant patient is not materially different from that of any other adult patient. As with any other patient, investigate the chief complaint, independent of the pregnancy, while keeping in mind how this may all be affecting the fetus. Keep in mind during the assessment of any female of childbearing age that she may be pregnant.
Once it is confirmed that the patient is pregnant, specific pregnancy questions should be asked. First find the GPAL values for the patient and document any history of abortion of any kind. Higher numbers of pregnancies that concluded with vaginal deliveries could result in a precipitous delivery, meaning the infant could deliver remarkably fast. Determine how the previous pregnancies ended, paying particular attention to any cesarean section history, especially if vaginal delivery is imminent. Vaginal birth after cesarean can be complicated and carries an increased risk of uterine rupture. In addition, determine if the patient has had prenatal care of any kind and if the physician has any concerns about the pregnancy or delivery.
Many problems are unique to the pregnant population. This section will look at the conditions that a woman could face exclusively because she is pregnant. This will include any problem related to pregnancy, not problems related to delivery. Each section will contain pathophysiology and assessment points to identify the problem, using both interrogation and the physical examination, and treatment options for the paramedic to consider.
Because of the increasing size and weight of the fundus, the expanded uterus, patients who are in their 3rd trimester should not lie on their back. This can cause supine hypotension syndrome, which results from the fundus lying on and compressing the inferior vena cava and possibly also the aorta. This can materially interfere with blood returning to the heart from the lower extremities and abdomen, possibly leading the patient to pass out after about 5–7 minutes if left uncorrected. Maternal hypotension means the placenta, and by extension the fetus, will be hypoperfused. Extended hypoperfusion of the fetus could result in fetal demise.
Patients will start to show early signs of shock before they pass out, including anxiety, nausea, dizziness, and tachycardia. If the patient is supine, such as if she has to be confined to a backboard, suspect this as a cause. The condition can be remedied if the backboard is tilted toward the patient’s left, or if the patient is allowed to lie in the left lateral recumbent position. If patient condition does not improve after these maneuvers, consider fluid resuscitation.
Hyperemesis gravidarum is a condition where the patient has excessive vomiting episodes, often in excess of 4 times daily. The cause is unknown but seems to be related to particularly high hCG concentrations in the blood. Patients with this condition often are sensitive to smells that can trigger vomiting. This can be so bad as to affect electrolyte balances and pH and water balance in the body. Patients often are hypovolemic and may be hypoglycemic as well.
The assessment of these patients is a general assessment that should include orthostatic vital signs if the patient is capable. Assess the skin and mucous membranes for evidence of dehydration. In addition to preparing for more vomiting during patient contact—which could be projectile vomiting—transport the patient in a position of comfort and initiate ECG monitoring and an intravenous line of NSS. If the patient is hypotensive or tachycardic, consider administering 500 mL NSS. Check the blood glucose level and administer 25 g D50 if <60 mg/dL. To help control vomiting, administer 4 mg ondansetron intravenously and 50 mg diphenhydramine intravenously or intramuscularly if medical control permits.
Hypertension in the pregnant patient is a significant cause for concern, particularly if it began while pregnant. If the patient was hypertensive prior to becoming pregnant, it is not necessarily an immediate threat as much as it would be if it is pregnancy-induced hypertension. Pregnancy-induced hypertension often is a sign of preeclampsia, a group of early warning signs that the patient may have eclampsia. The symptoms of preeclampsia include edema most often of the face, hands, and ankles; protein in the urine; and hypertension, all of which began or worsened after the 20th week of pregnancy. Preexisting renal problems, diabetes, and the African American race predisposes a patient to preeclampsia. A patient is diagnosed with eclampsia after the patient has a seizure in addition to these symptoms. Treatment for preeclampsia in the prehospital environment includes high-flow O2, especially if the SBP is >160 or the DBP is >105. Transport comfortably but quickly, preferably to the hospital of choice, possibly for emergent delivery.
First-line treatment of seizures from eclampsia is 4–6 g magnesium sulfate administered over approximately 15 minutes. Seizing will usually stop with just the loading dose. For extended transport times, a maintenance infusion of magnesium should be initiated at 1–2 g/hr and should be slowed if the patient shows a declining mental status. Although magnesium will likely control the seizure, if it persists, 4 mg lorazepam is the next line drug of choice. The blood pressure should be monitored and not treated prehospital because it needs to be slowly lowered to avoid fetal compromise. However, medical control may order 20–40 mg of labetalol every 15 minutes, or 5–10 mg of hydralazine every 10 minutes as needed to maintain an SBP between 140 and 160 mmHg and a DBP between 90 and 110 mmHg.
As mentioned earlier in this section, the patient may become diabetic as a result of being pregnant. The patient may present similar to any diabetic who is not pregnant and may have high or low blood sugar levels. This can be assessed and managed as previously discussed.
Toxoplasmosis is a parasitic infection that women can get, most commonly from handling cat litter or ingesting food contaminated with the parasite. Pregnant women are encouraged to eat only thoroughly cooked meat and to not change cat litter boxes. This disease does not have any symptoms and is detectable only with a blood test. Newborns also do not show any specific symptoms, but they may develop learning, visual, and hearing difficulties later in life.
This chapter has already discussed one of the major reasons for bleeding in the pregnant patient: the ectopic pregnancy. But several other conditions unique to the pregnant patient can involve spontaneous vaginal bleeding.
Abortion is the expulsion and death of a fetus prior to being viable outside the uterus. Depending on the text, this can be at any time prior to 20 or 28 weeks of gestation. For consistency, this text will use 20 weeks as the cutoff. What follows is an explanation of the degrees of abortion the paramedic may encounter in the field.
In spontaneous abortion, the body ends the pregnancy without warning. This can be caused by chromosomal abnormalities in the fetus, from a failed implantation, or from failed maintenance of progesterone from either the corpus luteum or the placenta. Illicit drug use increases the possibility of spontaneous abortion. In most cases, a finite cause cannot be identified. Treatment is limited to emotional support and prevention of shock. If the patient has not already done so prior to EMS arrival on the scene, apply a pad to the vagina but do not pack the vagina.
Elective abortion is a type of abortion that is a conscious decision on the part of the mother to end the pregnancy. If carried out in a doctor’s office, hospital, or clinic, there are not nearly as many complications as when the mother takes it upon herself to elicit the abortion. Toxic herbal and chemical preparations can be taken that make the blood toxic to the fetus, which also may have negative effects on the mother. Desperation may lead a person to insert various instruments into the uterus in an attempt to forcibly detach the placenta from the endometrium, which can lead to profuse and life-threatening bleeding. When encountered with a patient who has had or attempted to perform an elective abortion, remember to be professional and not pass judgment on the patient.
For any of a variety of reasons, a patient may come close to having a spontaneous abortion, also known as a threatened abortion. These reasons can include dehydration or malnutrition, where the mother’s body needs to sacrifice the fetus for its own survival. Reversal of the causative problem often can halt the abortion, and the mother can carry to term or closer to it. Alternatively, a threatened abortion may proceed all the way to a complete abortion or become an incomplete abortion. Patients who have experienced a threatened abortion and still have a viable pregnancy (fetal heart tones are present, and the fetus is moving as before) are usually placed on near total bed rest to prevent such symptoms from happening again. In a threatened abortion, although the fetus’s viability is threatened, it remains alive, the cervix remains closed (this is not assessed by paramedics), and fetal and placental tissue has not been passed. Treatment is aimed at supportive care for any presenting symptoms and should include emotional sensitivity and professionalism on the part of the responders.
In an inevitable abortion, the cervix has dilated; vaginal bleeding often is profuse and contains clots and may contain endometrial, placental, or fetal tissue. In this case, the abortion is not yet complete but cannot be stopped or reversed. Treatment should include emotional support whenever possible, but aggressive fluid resuscitation and treatment of shock are priorities.
An incomplete abortion occurs when only a portion of the products of conception—fetus, placenta, and amnion—are expelled while some remain in the uterus. An inevitable abortion may conclude as an incomplete abortion and require medical care to become a complete abortion. A complete abortion is where none of the products of conception remain in the uterus. Treatment for an incomplete abortion cannot be done in the field, and a paramedic’s care is limited to emotional support and treatment of any other secondary symptoms, such as septic or hypovolemic shock.
On rare occasions, the fetus may die, but the body does not expel it. This is a missed abortion. Treatment for a missed abortion is dilation of the cervix and curettage, which is scraping of the endometrial lining.
Abruptio placenta occurs when the placenta begins to detach from the uterine wall prematurely, often long before the infant has actually been delivered. There are many causes for this condition, including drug and alcohol abuse and smoking, but the most common reason is maternal hypertension. External blunt trauma is the next most common reason. Abruptio placenta may result in slight, moderate, or profuse vaginal bleeding and should be considered in cases of vaginal bleeding in late-term pregnancies. It is possible for the patient to lose a lot of blood to the point of being hypotensive yet show no or minimal external bleeding. The placenta or amniotic sac can prevent the blood from actually escaping the vagina. Therefore, placental abruption should be considered whenever the pregnant patient in the 3rd trimester appears to be in shock.
Treatment for placental abruption is supportive and should include high-flow O2, intravenous fluid infused at a rate to maintain a SBP >100 mmHg, and rapid transport to a hospital capable of handling emergency deliveries.
Placenta previa occurs when implantation has occurred low in the uterus and the placenta develops over the cervical os, or opening. Placenta previa can be described as marginal, partial, or complete, depending on its relationship with the os. In a marginal placenta previa, the placental edge lies extremely close to the os and could impact NSVD. In partial placenta previa, the placenta does obstruct the os to a measurable degree. The placenta completely covers the os in complete placenta previa.
This condition can be completely unknown to the mother who has not received any prenatal care and does not present a problem to either the fetus or the mother until delivery. In the patient who has had prenatal care, the mother will be scheduled for a cesarean section at about the 38th week of gestation to minimize the possibility of the body initiating natural childbirth. There is only 1 way out of the uterus naturally for the infant, and in the case of placenta previa, it is through its own blood supply. As the cervix starts to dilate in preparation for natural childbirth, vaginal bleeding will begin and remain constant or increase over time.
Treatment for the patient with placenta previa is the same as for abruption placenta: prepare for and treat for shock. In placenta previa, the paramedic should encourage the patient to breathe slowly and deeply through contractions to help the mother avoid pushing. Patients also may be transported in the knee-chest position, where the mother’s knees and chest are in contact with the stretcher, and her pelvis is the highest part of her body. This will temporarily help minimize the pressure of the infant on the placenta and “buy time” to get to the hospital without more bleeding.
Labor is the overall term for the process of delivering the fetus and the placenta and can be divided into 3 distinct phases. The 1st stage of labor begins with the onset of contractions of the uterus, called labor pains. These pains begin as an achy feeling, often in the upper abdomen or back. Many women describe them as similar to that crampy feeling that a person would get with diarrhea. Initially, the contractions may be as far apart as about 15 minutes, but they tend to get closer together as labor progresses. The timing of these contractions is typically measured from the beginning of a contraction to the beginning of the next, and the duration of a contraction is how long the pain lasts before fully subsiding. It is important as part of the assessment of the pregnant patient with contractions to measure and report both how long they last and the time in between each.
As the uterus contracts, the infant is forced into the cervix and eventually the vagina. As this happens, 3 major changes happen to the cervix. First, the cervix shortens and becomes thinner, which is called effacement. As this is happening, the os of the cervix begins to dilate and gets larger in diameter, eventually achieving a diameter of about 10 cm. Neither of these measurements and assessment points are something the paramedic will measure because these measurements are internal and require extensive training; however, it may be reported to the paramedic during an interfacility transport. Delivery is imminent when the patient is fully dilated and 100% effaced. A fully dilated cervix signals the end of the 1st stage of labor and the beginning of the 2nd. It often is at a point prior to the presentation of the head that the bag of waters (i.e., amniotic sac) ruptures (breaks), releasing a gush of amniotic fluid.
The 2nd stage of labor begins when the head of the infant is visible with simple inspection of the vulva, essentially simultaneous with full dilation of the cervix. The presentation of the head is called crowning. Although any part of the infant can present, the head is by far the most common, with the buttocks presentation (breach) being the 2nd most common. If the head presents, it will generally be face down and flexed with the chin in contact with the chest. At this point, contractions are typically <3 minutes apart, the strongest they have been thus far during labor, and often last a full minute, making them seem nearly constant to the mother.
As the head begins to present, it is incumbent on the paramedic to remain calm and appear in control, even though he or she will only be assisting a completely natural process. It often is difficult to decide whether to transport the patient who presents with contractions or stay on scene and await delivery. Some factors to consider in making this decision are as follows:
Contractions of a frequent interval and long duration signal an imminent birth. If a mother has had multiple births prior to the current pending delivery, this delivery often will by much faster—on the order of minutes rather than a couple hours that is typical of nulliparous patients. If the patient says that she needs to have a bowel movement, do not allow her because this reflex is caused by the infant pressing on the rectum similar to feces preceding a bowel movement. If the patient is considered at high risk or has not had meaningful prenatal care, unless delivery is imminent, it may be worth attempting to get to a hospital capable of high-risk deliveries rather than stay on scene.
If any of these are present, it is highly recommended to stay at scene and perform an emergency delivery. Establish a clean, preferably sterile, area around the patient but particularly under the mother’s buttocks and between her legs and prepare the OB kit every ambulance should have.
The following are the steps and events that occur during the 2nd stage of labor:
Proceed with newborn resuscitation guidelines from later in this chapter if needed.
The delivery of the child concludes the 2nd stage of labor.
The 3rd stage of labor begins once the neonate is fully delivered and concludes with the delivery of the placenta. The placenta will be approximately the size of a dessert plate. Do not tug on the remainder of the umbilical cord in an attempt to accelerate this process. Within about 30 minutes, the placenta should deliver with a few more contractions. If after an hour the placenta has not yet delivered, transport the patient to the hospital because this may indicate a problem. Place the placenta in a plastic bag and bring it to the hospital; the physician will check it to ensure that the entire placenta has been expelled. Placenta retained in the uterus can lead to a lethal postpartum hemorrhage.
The Apgar score is an assessment tool that assigns a numerical value to each assessment point. The score is calculated officially at 1 and 5 minutes of life, although the tool can be used at any time to evaluate the vitality of the newborn. For each section, assign the best score for the neonate from 0 to 2 and total the score for the 5 sections. Normal infants score 7 and higher.
| Letter | Meaning | Score | Description |
|---|---|---|---|
| A |
|
2 | Completely pink |
| 1 | Peripheral cyanosis (hands and feet) | ||
| 0 | Central cyanosis | ||
| P | Pulse | 2 | >100 |
| 1 | Present but <100 | ||
| 0 | Absent | ||
| G |
|
2 | Avoids noxious stimulus |
| 1 | Weak avoidance of stimulus | ||
| 0 | None | ||
| A |
|
2 | Actively resists extension of extremities |
| 1 | Weakly resists extension of extremities | ||
| 0 | None/limp | ||
| R |
|
2 | Forceful cry |
| 1 | Slow respiratory rate or gasping | ||
| 0 | None | ||
| 0–3 Severely depressed, critically ill newborn | |||
| 4–6 Moderately depressed, monitor closely, transport rapidly | |||
| 7–10 Normal | |||