Term
| Five factors affecting the process of labor and birth |
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Definition
Passenger (Fetus and placenta)
Passageway (Birth canal)
Powers (Contractions)
Position of the mother
Psychologic response |
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Term
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Definition
| Refers to the part of the fetus that enters the pelvic inlet first and leads through the birth canal during labor at term. |
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Term
| Three main presentations are what? |
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Definition
Cephalic presentation (Head first)
Breech presentation (buttocks first)
Shoulder presentation |
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Term
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Definition
The relation of the long axis (spine) of the fetus to the long axis (spine) of the mother.
Two primary lies are longitudinal or vertical, in which the spine of the fetus i s parallel with the spine of the mother; and transverse/ horizontal, or oblique, in which the spine of the fetus is at a right angle to the spine of the mother. |
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Term
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Definition
| Is the relation of the fetal body parts to one another. |
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Term
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Definition
Frank breech
Lie: Longitudinal or vertical
Presentation: Breech (incomplete)
Presenting part: Sacrum
Attitude: Flexion, except for legs at knees |
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Term
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Definition
Single footling breech
Lie: Longitudinal or vertical
Presentation: Breech (incomplete)
Presenting part: Sacrum
Attitude: Flexion, except for one leg extended
at hip and knee |
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Term
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Definition
Complete breech
Lie: Longitudinal or vertical
Presentation: Breech (sacrum and feet presenting)
Presenting part: Sacrum (with feet)
Attitude: General flexion |
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Term
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Definition
Shoulder presentation
Lie: Transverse or horizontal
Presentation: Shoulder
Presenting part: Scapula
Attitude: Flexion |
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Term
| Define biparietal diameter |
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Definition
about 9.25╯cm at term, is the largest transverse diameter and an important indicator of fetal head size (Fig. 13-4, B). In a well-flexed cephalic presentation the biparietal diameter is the widest part of the head entering the pelvic inlet.
[image] |
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Term
| What is the suboccipitobregmatic diameter |
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Definition
Of the several anteroposterior diameters, the smallest and most critical one is the suboccipitobregmatic diameter (about 9.5╯cm at term). When the fetal head is in complete flexion, this diameter allows it to pass through the true pelvis easily
[image] |
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Term
| How is fetal position abreviated? |
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Definition
Position is the relationship of a reference point on the presenting part (occiput, sacrum, mentum [chin] or sinciput [deflexed vertex]) to the four quadrants of the mother’s pelvis. Position is denoted by a three-letter abbreviation. The first letter of the abbreviation denotes the location of the presenting part in the right (R) or left (L) side of the mother’s pelvis. The middle letter stands for the specific presenting part of the fetus (O for occiput, S for sacrum, M for mentum [chin], and Sc for scapula [shoulder]). The third letter stands for the location of the presenting part in relation to the anterior (A), posterior (P), or transverse (T) portion of the maternal pelvis. For example, ROA means that the occiput is the presenting part and is located in the right anterior quadrant of the maternal pelvis (see Fig. 13-2). LSP means that the sacrum is the presenting part and is located in the left posterior quadrant of the maternal pelvis.
[image] |
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Term
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Definition
is the relationship of the presenting fetal part to an imaginary line drawn between the maternal ischial spines and is a measure of the degree of descent of the presenting part of the fetus through the birth canal.
[image] |
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Term
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Definition
| the term used to indicate that the largest transverse diameter of the presenting part (usually the biparietal diameter) has passed through the maternal pelvic brim or inlet into the true pelvis and usually corresponds to station 0. It often occurs in the weeks just before labor begins in nulliparas and may occur before or during labor in multiparas. |
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Term
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Definition
| Involuntary uterine contractions, signal the beginning of labor. Once the cervix has dilated, voluntary bearing-down efforts by the woman, called the secondary powers, augment the force of the involuntary contractions. |
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Term
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Definition
| When the stretch receptors in the posterior vagina cause release of endogenous oxytocin, which triggers the maternal urge to bear down. |
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Term
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Definition
| As soon as the presenting part reaches the pelvic floor, the contractions change in character and become expulsive. The laboring woman experiences an involuntary urge to push. She uses secondary powers (bearing-down efforts) to aid in expulsion of the fetus as she contracts her diaphragm and abdominal muscles and pushes. These bearing-down efforts result in increased intraabdominal pressure that compresses the uterus on all sides and adds to the power of the expulsive forces. |
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Term
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Definition
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Term
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Definition
| Brownish or blood-tinged cervical mucus that may be passed in response to the extreme congestion of the vaginal mucous membranes during the last two weeks of before term. |
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Term
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Definition
1st stage: Onset of regular contractions to full dilation of the cervix. Divided into three phases; Latent (effacement of cervix), active and transition phase (dilation and descent of presenting part).
2nd stage: full dilation to birth of fetus. Divided into latent (passive) and active (pushing) phases.
3rd stage: Birth of fetus until placenta is delivered.
4th stage: Arbitrarily lasts about 2 hours after delivery of placenta. Period of immediate recovery during which homeostasis is reestablished. |
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Term
| Cardinal movements of mechanism of labor |
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Definition
| engagement, descent, flexion, internal rotation, extension, external rotation (restitution), birth by expulsion. |
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Term
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Definition
| When the biparietal diameter of the head passes the pelvic inlet, the head is said to be engaged in the pelvic inlet. |
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Term
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Definition
| The head usually engages in the pelvis in a synclitic position (i.e., one that is parallel to the anteroposterior plane of the pelvis). Frequently asynclitism occurs (the head is eflected anteriorly or posteriorly in the pelvis), which can facilitate descent because the head is being positioned to accommodate to the pelvic cavity. |
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Term
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Definition
Descent refers to the progress of the presenting part through the pelvis. The degree of descent is measured by the station of the presenting
part (see Fig. 13-6). As mentioned, little descent occurs during the latent phase of the first stage of labor. Descent accelerates in the active phase when the cervix has dilated to 5 to 7cm. It is especially apparent when the membranes have ruptured. |
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Term
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Definition
As soon as the descending head meets resistance from the cervix, pelvic wall, or pelvic floor, it normally flexes so the chin is brought closer to the fetal chest. Flexion permits the smaller suboccipitobregmatic diameter (9.5cm) rather
than the larger diameters to present to the outlet. |
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Term
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Definition
| The fetuses head must rotate in order to get through the pelvis. |
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Term
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Definition
| When the fetal head reaches the perineum for birth, it is deflected anteriorly by the perineum. The occiput passes under the lower border of the symphysis pubis first, and the head emerges by extension: first the occiput, then the face, and finally the chin. |
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Term
| Restitution and external rotation |
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Definition
| After the head is born, it rotates briefly to the position it occupied when it was engaged in the inlet. This movement is referred to as restitution. |
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Term
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Definition
| After birth of the shoulders, the head and shoulders are lifted up toward the mother’s pubic bone, and the trunk of the baby is born by flexing it laterally in the direction of the symphysis pubis. When the baby has emerged completely, birth is complete, and the second stage of labor ends. |
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Term
| Average FHR at 20 weeks and at term. Normal range? |
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Definition
| 160 beats/min and 140 beats/min. Normal range is 110-160 beats/min at term. |
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Term
| Factors affecting fetal circulation |
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Definition
| Maternal position, uterine contractions, blood pressure fluctuations, and umbilical blood flow. Fetuses generally adapt and compensate to the stress. |
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Term
| What fetal changes prepare the fetus for initiating respirations immediately after birth? |
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Definition
• Fetal lung fluid is cleared from the air passages as the infant passes through the birth canal during labor and (vaginal) birth.
• Fetal oxygen pressure (Po2) decreases.
• Arterial carbon dioxide pressure (Pco2) increases.
• Arterial pH decreases.
• Bicarbonate level decreases.
• Fetal respiratory movements decrease during labor. |
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