What does fetal presentation refer to?
The part of the fetus that enters the pelvic inlet first and leads through the birth canal
What are the three main fetal presentations at birth?
- cephalic (head first)
- breech (butt or feet first)
Presenting part refers to what?
The part of the fetal body first felt by the examining finger during a vaginal examination
In a cephalic presentation, what is usually the presenting part?
In a breech presentation, what is usually the presenting part?
In a shoulder presentation, what is usually the presenting part?
What are the factors that determine the presenting part?
- Fetal lie
- Fetal attitude
- Extension or flexion of the fetal head
Describe what fetal lie is
The relation of the long axis (spine) of the fetus to the long axis (spine) of the mother
What are the two primary lies?
- Transverse, horizontal, or oblique
What is true of longitudinal/vertical lie?
the spine of the fetus is parallel with the spine of the mother
What is true of transverse, horizontal, or oblique fetal lie?
The spine of the fetus is at a right angle diagonal to the spine of the mother
What types of presentations occur with longitudinal lie?
cephalic or breech
If a fetus stays in this type of lie, vaginal birth cannot occur
An oblique lie, one in which the long axis of the fetus is lying at an angle to the long axis of the mother is less common and usually does what?
Converts to a longitudinal or transverse lie during labor
Describe fetal attitude
The relation of the fetal body parts to one another
The fetus assumes a characteristic posture (attitude) in utero because of what two things?
- Partly because of the mode of fetal growth
- partly because of the way the fetus conforms to the shapw of the uterine cavity
Describe the attitude of general flexion
The back of the fetus is rounded so that the chin is flexed on the chest, the thighs are flexed on the abdomen, and the legs are flexed at the knees. The arms are crossed over the thorax, and the umbilical cord lies between the arms and the legs
Membrane-filled spaces that are located where the membranous sutures that unite the bones in the fetal/neonatal skull intersect
Slight overlapping of the bones of the fetal skull that occurs during childbirth; it permits the skull to adapt to the various pelvic diameters
Largest transvers diameter of the fetal skull
Smallest anteroposterior diameter of the fetal skull to enter the maternal pelvis when the fetal head is in complete flexion
Relationship of the fetal presenting part to the four quadrants of the maternal pelvis
Term that indicates that the largest transverse diameter of the presenting part has passed through the maternal pelvic brim or inlet into the true pelvis reaching the level of the ishial spines
Relationship of the presenting part of the fetus to the imaginary line drawn betweel the maternal ischial spines; this is a measure of the degree of fetal decent through the birth canal
The two components of the maternal passageway or birth canal
bony pelvis and soft tissue
Shortening and thinning of the cervix during the first stage of labor; it is expressed as a percentage
Enlargement or widening of the cervical opening (os) and the cervical canal, which occurs once labor has begun; degree of progress is expressed in centimeters (cm) from less than 1 cm to 10 cm
Decent of the fetus's presenting part inot the true pelvis approximately 2 weeks before term for the primigravida and after uterine contractions are established and true labor is in progress for the multipara
Lightening or dropping
Primary powers of labor
Involuntary uterine contractions
Secondary powers of labor
bearing down or pushing
Brownish or blood-tinged cervical mucous representing the passage of the mucous plug as the cervix ripens in preparation for labor
The seven turns and adjustments of the fetal head, to facilitate the passage through the birth canal. In a vertex presentation what do these turns and adjustments include?
Mechanism of labor; engagement, desent, flexion, internal rotation, extention, external rotation (restitution) and expulsion
Pushing method during the second stage of labor characterized by a closed glottis with prolonger bearing down
Process of moving the fetus, placenta, and membranes out of the uterus and through the birth canal
Protein found in plasma and cervicovaginal secretions of pregnant women before the onset of labor; its presence is being used to predict the likelihood of preterm labor in women who are at increased risk for this complication
The first stage of labor is considered to last from when to when?
The onset of regular uterine contractions to full dilation and effacement of the cervix
The first stage of labor is divided into which three phases
The second stage of labor last from when to when?
From the time the cervix is fully dilated and effaced to the birth of the baby
The third stage of labor lasts from when to when?
From the birth of the baby until the placenta is delivered
The fourth stage of labor is the period of what?
What happens during the fourth stage of labor?
Hemostasis is reestablished
What are the four factors that affect fetal circulation during labor?
- Umbilical cord blood flow
Morphine-like chemicals produced naturally in the body, which raise the pain threshold and produce sedation
A vaginal examination during labor reveals the following information: LOA-1, 75%, 3cm. An accurate interpretation of this data would include which of the following? Choose all that apply
B.Station:3cm below the ischial spines
F:dilation:9cm more to reach full completion
a,c,d,e; station is 1cm above ischial spines (-1); 3cm more to reach full dilation of 10cm
Changes occur as a woman progressess through labor. Which of the following maternal adaptations would be expected during labor? Choose all that apply.
A.Increase in both systolic and diastolic blood pressure during uterine contractions in the first stage of labor
B. Decrease in WBCs
C.Slight increase in HR during the first and second stages of labor
D.Decrease in the gastric motility leading to nausea and vomiting during the first stage of labor
- systolic blood pressure increases with uterine contractions in the first stage whereas both systolic and diastolic blood pressurre increase during contractions in the second stage;WBCs increase
A nurse is instructing a group of primigravid women about the onset of labor. Which of the following signs could the women observe preceding the onset of their labors? Choose all that apply.
B.Weight gain of 2kg
F.Shortness of breath
- Quickening refers to the woman's first perception of fetal movement at 16-20 weeks of gestation; urinary frequency, lightening, weight loss of .5-1.5kg occur to signal that the onset of labor is near; backache, stonger Braxton-Hicks contractions, and bloody show are also noted; shortness of breath is relieved once lightening occurs reducing pressure on the diaphram
Right Occiput Posterior,cephalic (vertex) presentation, longitudinal lie (flexed attitude)
-1(station at 1cm above the ishial spines,engaged)
- RMA (right mentum anterior)cephalic face presentation,longitudinal lie, extended attitude.
- 0 (station at the ischial spines,engaged)
- 25% effacement
- 2 cm dilated
- LST (left sacrum transverse)breech presentation, longitudinal lie, flexed attitude
- +1 (station at 1 cm below the ischial spines)
- 75% effaced
- 6 cm dilated
- OA (occiput anterior),cephalic (vertex) presentation,longitudinal lie, flexed attitude
- +3 (station at 3cm below the ischial spines near or on the perineum)
- 100% effaced
- 10 cm (fully) dilated