Labour: 1st Stage (MID2000)

Labour: 1st Stage

• Labour is characterized by regular and coordinated muscular contractions of the uterus, leading to effacement and dilation of the cervix, followed by expulsive contractions that result in the birth of the baby and placenta.

Preparation for Labour: Uterine Changes

• Myometrial cells are capable of spontaneous activity independent of external stimuli, but contractions are prevented by uterotonic inhibitors during pregnancy.
• As pregnancy progresses, contractions gradually increase in intensity and frequency, leading to strong, synchronous, and effective labour contractions.
• Myometrial cells change structure, allowing them to contract more strongly and continue throughout labour.
• Electrical activity increases, the ratio of hormones changes, and myometrial cells become more responsive, with an increase in numbers of ion channels.

Preparation for Labour: Cervical Changes

• The cervix has a high content of connective tissue, resisting stretching during pregnancy.
• The process of ripening begins several weeks before myometrial contractions and is independent of contractions.
• Ripening is a softening process characterized by infiltration of leucocytes, an increase in water, and a decrease in collagen content.
• Stretching of the cervix results in the release of prostaglandin F2alpha and oxytocin, increasing uterine activity and initiating labour.

Hormones that Initiate and Play a Role in Labour

• Corticotrophin-releasing hormone (CRH) binds to different receptor types and promotes uterine contractions under the influence of oxytocin during labour.
• Prostaglandins (PGE2 & PGF2alpha) stimulate smooth muscle fibres to contract, form gap junctions, and increase calcium levels in myometrial cells, as well as soften the cervix.
• Oxytocin is released in response to tactile stimulation of the reproductive tract, increasing oxytocin receptors in decidua, stimulating the release of prostaglandins, and stimulating uterine pacemakers.
• Oestrogen increases sensitivity of myometrial oxytocin receptors, facilitating myometrial contractility.
• Progesterone suppresses uterine excitement during pregnancy, but its decrease before labour allows the uterotonic effect of oestrogen to dominate.

The Antenatal Period and Antenatal Care

Recap from MID1000

• Pregnancy is referred to as the antenatal period
• There are three trimesters:
  • First trimester: Week 1-12
  • Second trimester: Week 13-27
  • Third trimester: Week 27-birth
• G = Gravida (number of pregnancies)
• P = Parity (number of births >20 weeks)
• Primigravida: The woman is pregnant for the first time
• Multigravida: The woman has been pregnant before
• EDB = Estimated Date of Birth
• LNMP = Last Normal Menstrual Period
• VMR = Victorian Maternity Record (orange book)

Models of Care

• Many women are not aware of their options for care providers
• Models of care differ in outcomes
• Models to choose from:
  • Private midwifery care (home or hospital birth)
  • Public midwifery care (continuity of care, caseload/midwifery group-practice)
  • Public midwifery care (fragmented care)
  • Private obstetric care (usually the same obstetrician, birthing in a private or public hospital)
  • Public obstetric care (fragmented care, usually for "high-risk" pregnancies in public hospitals)
  • GP shared-care
  • Private midwife shared-care
  • Free-birth (no medical care)

Communication

• Key elements:
  • Language
  • Privacy and confidentiality
  • Listening skills
  • Style (conversational or checklist approach)
  • Accurate documentation and storage of notes

Physical Environment

• Considerations:
  • Privacy
  • Comfort
  • Noise levels and safety
  • Equipment and paperwork necessary

Personal Disclosure

• Partnership is about equality
• When to share personal information and when not to
• Avoid:
  • Holding oneself up as a role model
  • Imposing values and cultural practices
  • Generalizing experiences to all women
  • Being judgmental

Initial Antenatal (Booking-in) Appointment

• Objectives:
  • Health assessment
  • Baseline vital signs
  • Review pathology/scans
  • Identify risk factors
  • Identify education needs
  • Establish a professional relationship
  • Provide opportunities for questions
  • Book future appointments

Antenatal Tests

• Screening tests:
  • Aim to identify those at increased risk
  • Do not diagnose problems
  • Examples: NIPT (non-invasive prenatal testing)
• Diagnostic tests:
  • If screening test is positive, further testing is recommended
  • Examples: Amniocentesis
• Potential benefits and harms of screening tests

Every Antenatal Visit

• Checks:
  • Blood pressure
  • Fetal heart rate and/or fetal movements
  • Abdominal palpation (including fundal height and FHR)
  • Urine dipstick (if indicated)
  • Weight (if necessary)
  • Assessment of emotional well-being
  • Provide relevant appointment information
  • Allow time for questions and discussion

Discomforts of Pregnancy

• Common discomforts:
  • Nausea and vomiting
  • Backache
  • Tiredness
  • Leg cramps
  • Heartburn
  • Headache
  • Constipation
  • Hemorrhoids
  • Varicose veins
  • Vaginal discharge
  • Hormonal impacts on mood
• Strategies to manage these discomforts

Education

• Individualized education
• Topics may include:
  • Screening and diagnostic tests
  • Fetal movement patterns
  • When to call the hospital
  • Midwife phone numbers
  • Diet and exercise
  • Birth planning
  • Postnatal preparation

Allied Health (Potential Referrals)

• Hospital services:
  • Social worker
  • Physiotherapist
  • Dietician
  • Specialized clinics
  • Lactation consultant
• Community services:
  • Maternal and Child Health Centers
  • Australian Breastfeeding Association
  • PANDA/Beyond Blue
• Private services:
  • Chiropractor/osteopath/myotherapist
  • Pelvic floor physio
  • Acupuncturist
  • Yoga teacher or personal trainer
  • Naturopath
  • Doula
  • Student midwife (CoCE)
  • Private lactation consultant
  • Calm birth/hypnobirthing
  • Private midwife

Documentation

• Handheld record: VMR (Victorian Maternity Record)
• BOS database
• Medical record
• Referrals
• Pathology requests

Booking-in Visit

• Extensive list of what to review, document, and discuss:

  • Demographic information
  • Medical/surgical history
  • Obstetric history
  • Family history
  • Previous pregnancies and outcomes
  • Intended mode of feeding
  • Complete history
  • Lifestyle and nutrition
  • Vaccinations
  • Oral and dental health concerns### Education in Pregnancy

• A pregnant woman who consumes energy drinks daily requires education on healthy choices, just like a woman who smokes during pregnancy.

• Education is crucial for women to make informed decisions about their health during pregnancy.

Digital and Telehealth

• Digital health services have become increasingly common, especially due to the pandemic.
• Telehealth provides remote health consultations, increasing access to healthcare for those who are physically or geographically unable to attend face-to-face appointments.
• Telehealth contributes to better information sharing in healthcare, a major issue in all healthcare settings.

Blood Group Rhesus Incompatibility

• No notes provided for this topic

Minor Health Conditions in Pregnancy

• No notes provided for this topic

Hormonal Changes

• As the first trimester ends, the corpus luteum degenerates, and hCG levels drop.
• The placenta takes over producing oestrogen and progesterone in the second trimester, which continues to rise throughout pregnancy.
• These hormonal changes cease ovulation and menstrual cycles during pregnancy.
• Oestrogen and progesterone have important functions in pregnancy, but their steady increase can have negative side effects.

Adapations in Pregnancy

Uterus, Cervix, and Vagina

• The uterus undergoes substantial changes during pregnancy, growing from the size of a clenched fist to accommodate a full-term baby (approximately 3500g).
• The uterus grows from 50g to 1000g in the first 20 weeks, with its walls stretching to accommodate the growing baby, placenta, and amniotic fluid.
• At the beginning of the third trimester, the lower segment of the uterus thins.
• The cervix softens in late pregnancy, and the skin and muscles of the anterior abdominal wall stretch greatly.

Cardiovascular System

• The heart increases in size during pregnancy, increasing its cardiac output.
• Cardiac output increases by 40% in the second trimester due to a more efficiently performing heart.
• Total blood volume increases by 30-50% during pregnancy, ensuring extra blood flow to the placenta.
• The increase in blood volume is caused by increases in plasma volume and red blood cells.

Respiratory System

• Pregnant women often experience shortness of breath due to the growing baby encroaching on the lungs.
• The amount of air moved in and out of the lungs increases by nearly 50% during pregnancy.
• Pregnant women require a lower carbon dioxide level to trigger breathing, making them slightly alkaloid.

Renal System

• Progesterone relaxes the bladder, causing it to almost double in size, and the ureters, increasing the risk of urinary tract infections.
• Women often experience an increased urge to urinate during pregnancy, especially in the first and last months.
• The kidneys work extra hard to filter waste products from the woman's blood and the fetus's, resulting in increased urine production.

Gastrointestinal System

• The muscles in the gastrointestinal system relax, slowing down the rate of food squeezing out of the stomach and along the intestines.
• Women are advised to reduce substances that can constipate or increase acidity, such as alcohol and coffee, to help with slower gut motility.

Metabolic Changes

• Pregnancy is a diabetogenic state, requiring a progressive increase in insulin to reserve glucose for fetal needs.
• There is a faster insulin response, with doubling of insulin levels by late pregnancy, but a corresponding tissue resistance to insulin.
• Fat storage increases in the woman in the first two trimesters, but so does lipolysis and proteolysis, allowing the woman to gain energy from this source.

Psycho-Social Impacts

• In addition to physiological changes, there are many psycho-social changes during pregnancy, including fear, grief, stress, and relationship changes.
• The midwife's role includes creating a safe space for the woman to discuss her feelings, relationships, concerns, and fears.

Oral Health in Pregnancy

• Good oral health is important during pregnancy, as poor oral health is linked to premature births, low birth weights, and an increased risk of early childhood dental caries in children.