Pregnancy and Normal Labour Notes

Physiological Changes During Pregnancy

  • Weeks: Pregnancy measured from the first day of the last menstrual period.
  • Trimester: A phase of pregnancy (3 trimesters).
  • Obstetrics: Medical specialty for pregnancy and childbirth.
  • Early Pregnancy Unit/Assessment Clinic: Outpatient unit for early pregnancy advice/treatment.
  • Central Delivery Unit/Suite: Labour ward where babies are delivered.
  • Gravidity: Number of times a woman has been pregnant (includes miscarriages).
  • Parity: Number of times a woman has given birth to a fetus with >=24 weeks gestation (regardless of outcome).
  • Contractions: Uterine muscle tightening.
  • Foetus: Unborn child.
  • Neonate: Infant from birth to 4 weeks.

Trimesters

  • Trimester 1 (1-12 weeks):
    • Increase in hCG hormone.
    • Uterus supports foetus and placenta growth.
    • Increased maternal blood supply.
    • Foetus develops all organs.
    • Highest risk of miscarriage.
  • Trimester 2 (13-28 weeks):
    • Decrease in hCG.
    • Increased oestrogen and progesterone.
    • Placenta controls hormone supply to foetus.
    • Foetal movements start.
  • Trimester 3 (29-40 weeks):
    • Cortisol 3x higher than non-pregnant.
    • Maternal discomfort (weight, back pain, compressed bladder, SOB).
    • Baby fully developed.
    • Baby engages in pelvis for birth.

Cardiovascular Changes

  • Blood volume increases by ~40% to support organs and foetus.
  • Heart rate increases by ~20 bpm.
  • Cardiac output increases.
  • Heart tissue enlarges around ventricles.
  • Heart position shifts higher in the thorax.
  • Blood pressure is lower due to increased progesterone (muscle relaxant and vasodilator).

Respiratory Changes

  • Mucosal oedema in airways from increased oestrogen, increasing resistance to airflow and difficulty with SGA/BVM.
  • Diaphragm is pushed up 4cm.
  • Rib cage expands.
  • Respiratory rate increases.
  • Reduced capacity to take deep breaths.

Anatomical Changes

  • Uterus moves from pelvic to abdominal cavity.
  • Uterus increases in size up to 5x normal.
  • Uterine muscular wall strengthens and becomes more elastic.
  • Vaginal mucosa thickens.
  • Breasts enlarge and begin milk production.
  • Compression of organs (aorta, bowels, lungs).

Common Pregnancy Signs and Symptoms

  • Fainting: Low blood pressure, over exertion, dehydration.
  • SOB: Higher diaphragm reduces lung expansion space.
  • Abdominal Pain: Implantation, ligament pain, constipation.
  • Bleeding: Implantation, infection, cervical changes, miscarriage, preterm labour.
  • Back Pain: Hormones, posture change, joint pressure, stress, labour.
  • Chest pain: Acid reflux, PE, rib pain.
  • Nausea and vomiting: Morning sickness, hyperemesis gravidarum.

Important Questions to Ask

  • How many weeks pregnant?
  • Gravidity and parity?
  • Well-being during pregnancy?
  • Any known complications?
  • Are foetal movements usual (start around 16-24 weeks)?
  • Any vaginal discharge?
  • Birth plan?
  • Social services involvement?
  • Request maternity notes.

Impact of Pregnancy on Care

  • 5% of maternal deaths are due to trauma.
  • Left lateral tilt is important.
  • Shock can be delayed.
  • Delayed placental abruption.
  • If cardiac arrest, commence ALS – Resuscitation of mother benefits foetus. Aim to leave scene in 5 minutes.
  • Be aware of safeguarding concerns.
  • Empathy is vital.

Stages of Labour

  • First Stage: Dilation of the Cervix
  • Second Stage: Delivery of the Baby
  • Third Stage: Delivery of the Placenta

Pre-Labour

  • Cervix softens ('ripens').
  • Head in the pelvis, baby facing to the side.

Latent Phase

  • Contractions irregular and short but painful.
  • Cervix effaces (shortens) and begins to open (0-3cm).
  • 'Show' or mucus plug.
  • Lasts around 20 hours.
  • Woman is fine at home.

Early Labour

  • Contractions more regular, longer, more intense but variable.
  • Cervix thinning.
  • Baby begins to descend.
  • Woman is fine at home.

Active Labour

  • Contractions strong, every 3-5mins, intense.
  • Cervix opens toward full dilatation (3-6cm).
  • Baby descending.
  • Woman likely wants to be at booked place of birth.

Transition

  • Contractions every 3-5 mins and very intense.
  • Woman feels she can’t cope.
  • Rectal pressure at peak of contractions.
  • Membranes bulging if not already broken.
  • If not first baby, birth imminent.

Full Dilatation

  • Contractions every 60-90 seconds, intense and expulsive.
  • Strong urge to push with peak of contraction.
  • Membranes rupture if not already broken.
  • Blood-stained 'show'.
  • May open bowels (normal).
  • Head moulding and starting to rotate.

Assessment of a Woman in Labour

  • Observe and listen.
  • History: parity, gestation, complications.
  • How long has she been contracting painfully?
  • Count contraction rate.
  • Set of observations.
  • Any loss per vaginum?

Communication

  • Call the midwife.
  • Consider discussing with staff at booked place of birth; they will advise transfer if complications arise.
  • If birth imminent, remain on scene and call midwife.
  • Request a second ambulance with a paramedic.
  • Obtain informed consent.

Preparing for Birth

  • Consider Entonox.
  • Warm the room and towels/blankets; eliminate draughts.
  • Allow woman to choose a comfortable position.
  • Cover areas with plastic sheeting and sheets/towels.
  • Prepare a neonatal resuscitation area.
  • Give calm encouragement.
  • Open the delivery pack.
  • Put on sterile gloves when birth seems imminent.
  • Know where Carbetocin, Misoprostol and TXA are.

Birth Imminent Signs

  • Anal dilatation.
  • Perineum bulging.
  • Top of head ('vertex') visible when woman pushes; head may retreat between contractions in first baby.
  • Reassure that sensations are normal.

Factors Affecting Second Stage

  • Power (contractions)
  • Passenger (baby)
  • Passage (maternal pelvis)

Head Visible

  • Cephalic presentation = head first.
  • In a 'multip' (mother who has given birth before) birth may follow 'vertex visible' almost immediately.
  • In a 'primip' (mother giving birth for the first time), more of the head is seen with each push, but may take time.

Crowning

  • Head won’t retreat after this contraction.
  • Ask woman to breathe and not push.
  • Consider gentle pressure on top of baby's head to slow it down.

Head Born

  • Note the time.
  • (Shoulders rotate in mum’s pelvis).
  • If not first baby, baby’s body may follow head immediately.
  • If not, ask woman to push again with next contraction to deliver body.

Restitution

  • (Head turning to be in line with the shoulders).

Next Contraction

  • Woman starts to push and the baby's body starts to come.
  • Support baby's body as it is born and get ready to catch!

Birth

  • Note the time.
  • Pass the baby through mother’s legs for her to pick up, or place baby on her abdomen if the mother is sitting.
  • Skin-to-skin, dry and cover with warm towels.
  • Place hat on baby’s head.
  • Observe baby’s condition. If crying no further action required except further observation.
  • Leave cord alone.
  • If not crying after a few seconds, stimulate by rubbing with a towel.
  • If not responding to stimulation, cut and clamp cord and remove baby to your resuscitation area.

Post-Birth

  • Keep mum and baby skin to skin, dry and warm.
  • Nuzzling at breast (oxytocin release).
  • Observe and record blood loss.
  • Don’t pull on the cord.

Effects of Oxytocin

  • Encourages production of breast milk.
  • Promotes bonding and attachment.
  • Inhibits stress.
  • Decreases blood pressure.
  • Encourages contractions for placenta delivery.

Placenta Delivery

  • Uterus contracts (painlessly).
  • Placenta separates from uterine wall, causing small gush of blood and lengthening of cord.
  • Mother may become uncomfortable in lower back/abdomen/rectum).
  • Ask woman to push placenta out in upright position if possible.
  • Uterus contracts strongly to prevent haemorrhage.
  • 'Afterpains' may start in a 'multip'.
  • Collect placenta in a bowl or bag for inspection and disposal by midwife.

Cutting the Umbilical Cord

  • Cord continues to pulse and give the baby blood and oxygen during transition to extra-uterine life until cut.
  • Do not clamp the cord earlier than 1 minute after birth unless baby has a heart beat less than 60/min that is not increasing.

Delayed Cord Clamping

  • Extra blood flow transferred through the placenta.
  • Transfer of iron impacts baby’s brain development.
  • Stabilises baby’s blood pressure.
  • In premature babies, ensures good red blood cell count.

After Care

  • Give mother a clean sanitary towel.
  • Keep bloodied linen and inco sheets for midwife to examine and weigh for blood loss.
  • Keep mother and baby covered, skin to skin to keep both warm, encourage mum to breast feed.
  • Observe blood loss - should not be heavy or constant.
  • Record a set of observations - temp, pulse, BP and baby’s temp.
  • If midwife hasn’t arrived, liaise with the Delivery Suite for further advice.
  • Document all care and conversations.
  • Consider feedback to 999 call handler / desk if applicable.

Assessment of Baby

  • APGAR (Appearance, Pulse, Grimace, Activity, Respiration)

APGAR Score

  • Appearance (Skin Colour):
    • 0: Blue/Pale
    • 1: Blue extremities (Acrocyanosis)
    • 2: No Cyanosis
  • Pulse Rate:
    • 0: Absent
    • 1: <60
    • 2: 60-100
  • Grimace (Response to Stimulation):
    • 0: No Response
    • 1: Grimace
    • 2: Cries
  • Activity (Muscle Tone):
    • 0: Floppy
    • 1: Some flexion
    • 2: Flexes and resists extension
  • Respiration:
    • 0: Absent
    • 1: Gasping
    • 2: Strong cry