Labour is a series of repetititive uterine contractions, lasting 30-60 seconds, associated with progressive cervical dilation and effacement of the cervix. Term is 37-42 weeks, with preterm before and postterm after.
Can be associated with "bloody show", diarrhea (because of prostaglandin), or rupture of membranes.
Engagement is the descent of the widest part of the fetus through the pelvic inlet. This normally occurs 2-3 weeks before labour in nulliparous women and may occur any time before or after onset of labour in multiparous women.
False Labour occurs with Braxton-Hicks contractions are not associated with progressive cervical dilatation and effacement. They are usually irregular and painless, or associated with mild pain only.
Cervical incompetence is dilation in the absence of contractions. It occurs when the cervix dilates and cannot keep the baby inside, and is neither true nor false labour.
When documenting obstetrical history, use bullets and acronyms as appropriate. Consise is important.
birth history
|
medications past medical history family history
|
group B strep status contractions
|
ruptured membranes |
Vitals of mother and baby
Abdominal exam
Leopold's maneuvers to determine position of fetus
Presentation
PV exam
0 |
1 |
2 |
3 |
|
dilation |
closed |
1-2 |
||
effacement |
0-30 |
40-50 |
60-70 |
80+ |
station |
-3 |
|||
consistency |
firm |
|||
position |
post |
Sterile speculum exam
First ensure labour is occurring
Progress as per primip/multip
Normal HR 120-180
Variability changes in short term/long term
Accelerations: increases of 15 bpm x 15 sec above baseline
Decelerations:
can use tophometer or scalp monitoring (more accurate; used if worrying FHR, multiples)
Non stress test
Why? depends on in 1st or 2nd stage
Options depend on circumstance
Duration of labour can be hard to quantify, as onset is subjective and poorly defined. Duration (in hours) varies widely:
nulliparous |
multiparous |
|
Stage I |
8 (2-12) |
5 (1-10) |
Stage II |
1 (0.25-1.5) |
0.25 (0-0.75) |
Stage III |
0.25 (0-1) |
0.25 (0-0.5) |
total |
9.5 (2.25-14) |
6 (1-10.25) |
Stage I lasts from the onset of labour to full cervical dilatation (10 cm).
During the latent phase (0-4 cm) it appears little is happening, but contractions become more coordinated, stronger, and efficient. The cervix softens, effaces, begins to dilate and angle anteriorly. It lasts avg 8.6 hours in nulliparous patients and 5.3 hours in multiparous women.
Contractions are relatively painless and initially occur every 3-4 minutes. Contractions become stronger and more frequent as the cervix slowly dilates. Spontaneous rulture of membranes may occur towards the end of the latent phase.
During the active phase, which begins when cervix is 3-4 cm dilated, labour progresses much more rapidly. The normal rate of dilatation is 0.5-1 cm/hr in nulliparious and 1.2 cm/hr in multiparous women. It lasts on average 5.8 hours in nulliparous and 2.5 hours in multiparous women.
Contractions can become more painful as the active phase continues, and women may feel a desire to push alhtouhg this is not wise until the cervix is fully dilated.
Progress in the first stage is measured in terms of cervical effacement, dilatation, consistency of the cervix, position of the cervix, and descent of the fetal head.
Progress is dependent on the 3 P's:
Include writeup and link on position.
The second stage of labour lasts from the period of full dilation to delivery.
passive phase: from full dilatation until head descends to pelvic floor via
active: when bearing down efforts begin accompanying each contraction.
Progress in the second stage can be negatively affected by epidural analgesia through inhibition of oxytocin; augmentation may be required.
Progress is again dependent on the three P's:
Descent
Flexion
Internal Rotation
Extension
External Rotation/Restitution
Delivery/Expulsion