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BEH3161 – Paramedic Management of maternal and neonatal health Summary Notes Week 1 à Learning objective 1: Revise the anatomy of the reproductive system TYPES OF PELVIS Most common à Learning objective 2: Revise the process of fertilization and implantation BASICS OF EGG DEVELOPMENT Oogenesis (the creation of eggs/oocytes) by the ovaries occurs during gestation. So when a baby girl is in her mothers womb, the babies entire egg supply (2-­‐4 million eggs) will be created BUT will remain in an inactive state. Once the girl reaches puberty her reproductive cycle will commence and 1 egg (primary oocyte) in the ovaries will mature and become activated (secondary oocyte) each month. This allows the egg to be fertilized by sperm. After an egg matures it is pushed out of the ovary in a process called ovulation. During Gestation: (Gestation until start of adolescents) MITOSIS MEIOSIS 1 STARTS Oogonia 2n Primary Oocyte (7 months gestation) Primary Oocyte (in meiotic arrest until adolescene) 2n 2n Adolescents to fertilization/menstruation: MEISOSIS 1 MEISOSIS 2 Secondary Oocyte Oovum Zygote (maturation of single primary ooycte that will be ovulated) 2n (following implantation of sperm Meisosis 2 occurs) 1n (Once the sperm and egg nucleus have combined) 2n + polar body + polar body NOTE: If the Secondary Oocyte is NOT fertilized by a sperm, then Meiosis 2 does NOT occur and is discharged from the body in the process of menstruation. Basic Egg development Video: https://www.khanacademy.org/science/health-­‐and-­‐medicine/human-­‐
anatomy-­‐and-­‐physiology/reproductive-­‐system-­‐introduction/v/basics-­‐of-­‐egg-­‐development EARLY EMBRYO DEVELOPMENT Day 4 Day 5 Day 6-­‐7 Day 10 Embryo is called a morula – Mass of cells in a solid ball (twins may form at this stage) Embryo becomes a blastocyst made up of: Inner cell mass (Embryoblast à embryo) Outer cell mass (Trophoblast à placenta) Implantation in the endometrium of the uterus Primitive uteroplacental Full Implantation into the endometrium by circulation formed blastocyst. End of Week 2 Start of Week 3 End of Week 3 End of Week 8 Primary – finger like projections form Secondary – Some cells differentiate into foetal blood capillaries Tertiary – Foetal blood circulates Embryo becomes a fetus Chorionic Villi à Learning objective 3: Revise the critical periods of embryo and Fetal development Organogenesis – is the development of organs. It occurs from 3 weeks and is most prolific in the first 12 weeks. It is for this reason that this period is referred to as the most critical for development. à Learning objective 4: Define and differentiate between Teratogenic and Foetotoxic factors Teratogenic Factors – An external influence causing harm or death to the developing foetus. • Non-­‐maternal related disease • Medications • Alcohol • Environmental agent Foetotoxic Factors – Maternal or foetal factors that may cause birth defects or abnormalities to the foetus • Maternal related illness (e.g pre-­‐eclampsia) • Injury • Infection (sepsis) • Haemorrhage • Uterine abnormalities • Cardiac Arrest à Learning objective 4: Outline the functions of the placenta, amniotic sac and umbilical cord. The placenta is a flattened disc shaped organ that nourishes and maintains the fetus via the umbilical cord. It has five (5) specific functions: 1. Nutritive 2. Respiratory 3. Excretory (wastes) 4. Endocrine 5. Barrier Placenta Video: https://www.khanacademy.org/science/health-­‐and-­‐medicine/human-­‐
anatomy-­‐and-­‐physiology/reproductive-­‐system-­‐introduction/v/meet-­‐the-­‐placenta The amniotic sac is a thin, transparent pair of membranes which hold the developing fetus until shortly before birth. • The inner membrane (the amnion) contains amniotic fluid, about 500-­‐1500ml, and the baby • The outer membrane (the chorion) is a part of the placenta and is adhered to the decidua. o Between each layer is a further ~200ml of amniotic fluid Amniotic fluid is a clear, pale, straw coloured fluid formed by secretions of amniotic cells and the foetus. It is made up mainly of water (98%) but also contains glucose, protein, sodium, urea & Creatinine and lanugo (hair) and vernix (waxy substance on babies skin). Amniotic fluid has a characteristic sweet odour (like semen…) and replenishes itself every 3 hours. Functions of amniotic fluid include: • Equalise pressure around the foetus • Cushions foetus from external compression •
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Provides constant temperature Provides fluid for the foetus to swallow Allows freedom of movement for the foetus Lubricates the membranes and foetus The umbilical cord is the conduit between the developing embryo or foetus and the placenta. It is 2-­‐3cm in diameter and 30-­‐90cms in length. The umbilical cord filled with a protective substance called Wharton’s jelly and cases: • 2 Arteries (carrying waste and carbon dioxide) and • 1 Vein (carrying oxygen, nutrients and hormones to baby) False knots are simple kinks in the cord and have no clinical significants. True knots occur when there is an actual knot in the umbilical chord and this can affect uteroplacental circulation. True knot False knot à Learning objective 5: Overview of the 3 trimesters A pregnancy is dived into 3 trimesters, each spanning approximately 13 weeks. • 1st trimester – From conception to 13 weeks o Rapid embryo/foetal development o Uterus remains in the pelvis nd
• 2 trimester – From 13 weeks to 26 weeks o Foetus continues to develop o Uterus moves out of pelvis into abdomen • 3rd trimester – From 26 weeks until birth of the baby o Lower segment of uterus stretches o Uterus continues to move up o Foetal development slow & baby fattens à Learning objective 5: Define the 3 stages of Labour First – painful regular contractions resulting in cervical dilatation to 10cm (full dilation) • 3 phases: latent, active & transition Second – Full dilation until arrival of the baby • 2 phases: lull, expulsive Third – From the birth of baby until delivery of the placenta Time: Primigravida: 12-­‐16 hrs Multigravida: 4-­‐10 hrs Primigravida: 30-­‐90mins Multigravida: 5-­‐60mins Primigravida: 5-­‐60mins Multigravida: 5-­‐30mins à Learning objective 6: Discuss the normal maternal physiological changes during pregnancy System Physiology Cardiovascular ↑ Blood volume (30-­‐50%) à Heart murmurs may be heard • RBC volume ↑18% • Plasma volume ↑ 40-­‐50% à haemodilution ↑ Heart Rate (15-­‐10bpm) ↑ Stroke Volume Therefore ↑ Cardiac Output (35-­‐50%) However Blood Pressure ↓ slightly during 1st & 2nd trimester, BP decrease due to ↓ resistance • Vasodilation (caused by progesterone) • Low pressure placenta rd
BP during 3 trimester is close to normal (progesterone peaks by 32/34 weeks Some woman experience Supine Postural Hypotension, As the uterus grows, it puts pressure on and partially occludes the inferior vena cava. This reduces preload and hence can cause hypotension. Respiratory The anatomical position of the heart shifts up and slightly to the left. Heart volume increases (from 70ml to 80ml) causes ↑ ANP à Diuresis ↑ Demand for O2 (↑ Consumption of O2 15%) ↑ Minute ventilation (caused by progesterone) • 300ml ↑ Inspiratory capacity • 200ml ↓ Expiratory reserve • Tidal volume ↑ 200ml (from 500 to 700) i.e the mum is taking deeper breaths Enlarging uterus puts pressure on the diaphragm causing it to rise upto 4cms. Rib cage flairs and chest wall circumference increases to compensate pH ↑ to 7.44 (from 7.40) – chronic respiratory alkalosis •
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Endocrine The blood becomes more basic due ↓ PaCO2 The bodies buffer system partially compensate by removing -­‐
bicarbonate (PaHCO3 ↓) Placental Hormones Progesterone Assists in blastocyst implantation and relaxes smooth muscle throughout the body. It is produced initially by the corpus luteum Oestrogen Stimulates growth (eg uterus and breast) and pliability of connective tissue. It is produced initially by the corpus luteum HPL insulin antagonist Relaxin causes relaxation of ligaments Pituitary gland Posterior: -­‐ Release oxytocin which stimulates uterine contractions Posterior: -­‐ Releases prolactin (initial milk production) -­‐FSH & LH suppressed (menstruation) Reproductive HCG maintains pregnancy by stimulating release of progesterone and oestrogen Thyroid gland Uterus Vagina ↑ size (60g à 1000g) ↑ capacity (10ml à 5L) All three layers enlarge Connective tissue loosen and secretions increase. ↑ glycogen in cells à result in ↑ risk of yeast infections and STIs. -­‐ e.g. candida albicans & trichomonas Cervix Cell proliferation Secretes thick, sticky mucous plug -­‐ Expelled during labour (show) -­‐ Softens during labour (Goodells sign) Becomes enlarged, ↑ capacity to bin thyroxin (foetul development) Breasts ↑ size Nipples become more erect and areola darken. rd
Produce colostrum in 3 trimester Ovaries Follicles do not mature & no ovulation. Corpus luteum produces progesterone until 12 weeks, then production is taken over by the placenta Blood ↑ Blood volume (40-­‐50%) ↑ White cell count (WCC) ↑ Red cell mass (18%) ↑ Plasma volume (50%) Depression of cell-­‐mediated which is essential to survival of the foetus however: Results in physiological anaemia ↑ Clotting factors and fibrogen ↓ Fibrolytic activity ↑ susceptibility to viral infections Protects from hemorrhage but Results a hypercoagulable state Hence ↑ risk of thromboembolism Gastrointestinal ↓ tone and mobility of bowel smooth muscle which ↑ intra-­‐gastric pressure caused by increasing size of uterus ↑ Acid secretions during 2nd trimester -­‐ Can cause heart burn & gastric reflux -­‐ Both can result in constipation Genitourinary Fundus progressively rises: -­‐ Suprapubic 12 weeks -­‐ Umbilicus by 24 weeks -­‐ Coastal margin by 36 weeks ↑ Blood blow to kidney therefore ↑ GFR ↑ Na retention (interstitial fluid ↑) Musculo skeletal ↑ weight (11.5-­‐13kg) ↑ relaxation of ligaments Ureter dilate & bladder relaxes Uterus puts pressure on bladder ↑ micturition ↑ urinary stagnation ↑ risk of UTI RAS compensation to counter vasodilation ↑ pressure on sciatic nerve ↑ curve in lumber spine (lordosis) Physiological changes video: https://www.khanacademy.org/science/health-­‐and-­‐medicine/human-­‐
anatomy-­‐and-­‐physiology/pregnancy/v/pregnancy-­‐physiology-­‐i à Learning objective 7: Discuss the process and importance of taking an obstetric history in an emergency setting Taking a history of the pregnant woman provides context to the S&S, assists with clinical judgement and allows paramedics to prioritise treatment, management and transportation decisions. Obstetric clinical approach (initial): • Windscreen survey • Primary survey o D o RABC • Secondary survey o History (EPOMS see below) o Vital signs EPOMS mnemonic Component Description Gather data about the current presentation Event à Labour (Is the patient in labour? Which stage?) à Contraction (Frequency? Length? No. in 10mins?) à Baby (What is the current state of the baby?) à Bleeding (Are there signs of bleeding) à Pain (Is the mother in pain) Pregnancy Gather data about the Hx of THIS pregnancy Obstetric Gather data about the pts full obstetric hx Medical Gather data about pts medical hx Social à Gestation à Problems à Position at last check up à Previous outcomes and complications (Large babies? Prem births?) à Ps & Gs à AMPLE Gather data about social conditions that may affect treatment/decisions à Family details à Hospital booked