Labour and Delivery

History

When documenting obstetrical history, use bullets and acronyms as appropriate. Consise is important.

Right Now

Physical Exam

Vitals of mother and baby

• fetal heart rate (doptone, NST)

Abdominal exam

• symphysis to fundal height

Leopold's maneuvers to determine position of fetus

Presentation

PV exam

Sterile speculum exam

• sterile q-tip, with nitrosine or ferning under microscope

Assessing Progress in Labour

First ensure labour is occurring

Progress as per primip/multip

• PV exam q2hours: more frequent if pain is substantial,

Fetal Monitoring

Normal HR 120-180

Variability changes in short term/long term

Accelerations: increases of 15 bpm x 15 sec above baseline

Decelerations:

• depends on...

can use tophometer or scalp monitoring (more accurate; used if worrying FHR, multiples)

Non stress test

Stage I

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.

During the first phase, mothers should be made comfortable and not push until the cervix is fully dilated.

Mothers may be more comfortable in a variety of poses, including sitting, standing, or showering.

As food will not pass through the gut during labour food should be avoided, especially if general anesthetics are possibly to be used. However, low-fibre, low-fat meals or drinks likely pose little hazard, and may in fact prevent ketoacidosis. (O'Sullivan et al, 2009).

The following should be monitored during the first stage:

• pulse, temperature, and blood pressure every 2 hours
• assess frequency, strength, and intensity of uterine contractions
• monitor fetal heart rate every 15 minutes
• assess cervical dilatation every 4 hours to determine progress and descent of presenting part
• discuss ongoing analgesic needs
• determine position of head

Progress is dependent on the 3 P's:

• Power: can do amniotomy if membranes are intact or augment with oxytocin
• Passage: shape cannot be altered - gynecoid, android, anthropoid, platypoid. Android and platypoid makes passage more difficult.
• Passenger: both head diameter and position are important; flexed head is best. Position is measured by relationship of occiput to the pelvis. Head can flex and mold to the shape of the bony pelvis

Stage II

The second stage of labour lasts from the period of full dilation to delivery.

• duration: nulliparous 30 minutes-4 hours (avg 50 minutes); mulitparous 5 minutes-2 hours (avg 20 minutes)

passive phase: from full dilatation until head descends to pelvic floor via

• descent of the fetal head usually only begins near full dilatation and in the 2nd stage, and is measured by station, represented by the ischial spines.
• protracted progress if less than 1 cm/hr in nulliparous women and less than 2 cm/hr in multiparous
• arrested if no descent over one hour in nulliparous and 30 min in multiparous

active: when bearing down efforts begin accompanying each contraction.

• strong desire to bear down; rectal pressure
• feelings of increased nausea and vomiting as the cervix reaches full dilatation

Progress

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:

• power of contractions
• passage
• passenger: flexion or position can be enhanced using manual, vacuum, or forceps technique

Six Cardinal Mechanisms of Labour

Descent

• occurs prior to onset and then throughout labour, with other mechanisms superimposed on it
• occurs at greater rate during latter part of 1st stage and 2nd stage

Flexion

• present before labour to some degree due to natural muscle tone
• further encouraged during labour by resistance from cervix, walls of pelvis, and pelvic floor
• optimizes presenting diameter of head

Internal Rotation

• head enters transversely and then rotates so that occiput is turned towards symphysis pubis (OA, occiput anterior position)
• 20% of the time, the head rotates OP, occiput posterior, though at least 75% of fetuses will rotate back as labour progresses

Extension

• to follow the path of the vagina, as the head moves under the symphysis it needs to move from flexion to extension
• make sure there's not too much extension
• crowning - when the largest diameter of the head is encircled by the vaginal opening, occurs during extension

External Rotation/Restitution

• the delivered head now rotates back to the transverse position, as it originally was, realigning the head with the back and shoulders

Delivery/Expulsion

• as descent continues, anterior shoulder delivers under the symphysis pubis, followed by the posterior shoulder. The rest of the body quickly follows

Stage III

• delivery of baby and placenta; duration avg 5-10 min; range 0-30 min
• signs of placental separation:
  • gush of blood from vagina
  • ubbilical cord lengthening
  • fundus of uterus moves up into abdomen
  • uterus becomes firm and globular
• watch closely for postpartum hemorrhage
• inspect cervix, vagina, and perineum for lacerations and repair if necessary
• inspect placenta to ensure complete removal

Stage IV

• especially during the 1st hour, the risk of postpartum hemorrhage is highest

Lochia is post-partum discharge, which can last up to 6 weeks

Vacuum

Assisted delivery

Good option for:

• full dilation (C section otherwise)
• low enough for it to be safe (+2 or +3)
• >35 weeks
• multiparous
• good progress
• good maternal effort

complications:

• pop-off: three is the limit
• uncuccessful: forceps, C section
• hematoma
• subgaleal bleed

Forceps

Good option for

• arrest in 2nd stage
• multipl
• maternal effort
• ++ Caput
• analgesia
• < 35 weeks

fully dilated

station +1 - +3

know position

analgesia (epidural, pudendal block ideal)

neonates

ability to do the CS

Potential complications

• unsc
• lacerations
• maplacement
• hematoma
• shoulder dystocia
• fracture

Platelets

Platelet normally 150-400 x 109/L

Platelets are acute phase reactants, so a low count may suggesr sepsis or coagulopathy (ie pregnancy-induced hypertension in HELLP syndrome - hemolysis, elevated liver enzymes, low platelets)

<150 warrants mention and <100 is concerning; if platelets are less than 40x 109/L, spontaneous bleeding can occur, ie into the neonatal cerebral ventricles.

A count higher than 400 may indicated fungal infection in those susecptible

Hemoglobin

Hgb

adult females 120-145 g/L

neonates 160-200 g/L

In a situation of acute hemorrhage, the hgb will be unchanged. It will take 3-12 h for fluid volume to be replaced and hgb to drop

RBC, hematocrit, MCV, MCH, MCHC not as helpful acutely, but can assist with explanation of type of anemia.

White Blood Cell Count

WBC

women in labour have a higher WBC (10-21) due to the stress reaction

sepsis in labour can lead to 16-24

Neonates

• first 24 hours of life: up to 24x109 (stress reaction)
• 24-48h: 12-20
• after 48h: 4-12
• a corrected WBC neonatal count is the manual count of WBCs; an automated count may include nucleated RBCs due to the stress of birth

Manual Differential

A manual differential will give band count.

An infection will lead to neutrophils

Neutrophils

The more immature cells circulating, the more concerning the situation.

If there is a major blood loss

Other

Kleihauer test

indicated percentage of fetal RBCs in the mother's circulation. Normal 0-0.2%.

If mother needs WinRho therapy, and the Kleihauer result exceeds 0.2%, the dosage of WinRho must be adjusted upwards.

It is normally only requested in Rh-negative mothers, but also can be ordered on any mother in whom fetal-maternal hemorrhage is suspected (ie abruption).

ABO/Rh type

read carefully to see whether it refers to mother's blood or cord (CD) blood

DAT Direct Antibody Test

measures presence of antibodies

WinRho A/D suggests antibodies have been triggered by WinRho, not infant.

A positive result in an infant suggests increased risk of hemolytic hyperbilirubinemia.

Blood Chemistries

Cord Gases

arterial - reflects neonate's status at moment of delivery

venous - reflects mother's status at that time, so is almost always more normal than the arterial result.

pH arterial:

• normal adult: 7.35-7.45
• infant at birth: >7.2
• neonate: 7.32-7.42

pCO2 arterial:

• normal adult: ~40 mmHg
• infant at birth: <60 mmHg
• neonate: 30-45 mmHg

BE

HCO3

pO2: always very low in a cord arterial sample

• irrelevant in a cpillary heel stick sample

Bilirubin

• total = conjugated plus unconjugated
• babies almost always have unconjugated

protein

• total protein = albumin, immunoglobulins, etc
• TProt correlates with albumin
• albumin transports unconjugated bilirubin, preventing it from crossing the BBB
• a low albumin leads to increased risk of kernicterus, even though bilirubin levels can be normal
• albumin levels will be low in neonates who are preterm, small for gestational age, or otherwise malnourished

ESR and CRP

• non-specific; may be elevated in hemolysis or injury
• CRP faster than ESR