Pregnancy Flashcards
Describe the Excitement Phase of Coitus
Vaginal Lubrication
Clitoral Engorgement
Inner 2/3 of Vagina lengthens and expands
Describe the Plateau Phase of Coitus
Further increase in muscle tone/HR/BP
Bartholin Gland Secretion
Describe the Orgasmic Phase of Coitus
Orgasmic platform contracts rhythmically 3-15 times
Describe the resolution phase of Coitus
Everything returns to normal
No refractory period so multiple orgasms possible
Describe the 6 stage process of conception
1) Sperm is deposited at External Os, where it stays in reservoir at posterior fornix, becoming more liquified
2) Oxytocin stimulates Uterine Contraction along with sperms own propulsive movements
3) Sperm becomes capacitated (changes from beat to whip like action, exposes acrosome enzymes)
4) Sperm binds to ZP3 protein on Zona Pellucida allowing Calcium to enter, increasing CAMP
5) Proteolytic enzymes are released, allowing penetration of Zona Pellucida
6) Increased Calcium causes egg cell membrane to depolarise (preventing polyspermy), cortical reaction causes secondary block
State four endocrine Maternal adaptations in Pregnancy
Increased Oestrogen
Increased Progesterone
Increased Thyroid Binding Globulin
Increased Anti Insulin Hormones
What is the role of increased Oestrogen in pregnancy?
Increases breast tissue growth
Water Retention
What is the role of increased Progesterone in pregnancy?
Relaxes smooth muscle
What is the effect of increased Thyroid Binding Globulin in Pregnancy?
Oestrogen causes the increase in TBG
Results in more T3/T4 binding, and subsequently less free T3/T4
TSH then increases, to bring free T3/T4 up to normal level
So overal free T3/T4 remains the same but total T3/T4 increases
Important as baby’s thyroid gland doesn’t function until second trimester therefore is reliant on maternal hormones until that point
Name three Anti Insulin Hormones
Human Placental Lactogen
Prolactin
Cortisol
Why are Pregnant Women at increased risk of Ketoacidosis?
Mother switches to lipids as an alternative source of energy to conserve free glucose for foetus
State 5 Maternal CVS changes in Pregnancy
Blood Pressure (drops for first and second, rises slightly for third)
Cardiac Output increases by around 40%
Plasma Volume Increases
Varicose Veins (Uterus compresses pelvic veins)
Maximum intensity shifted to left (diaphragm pushes on Heart)
Why does blood pressure decrease in early trimesters?
Due to Progesterone causing relaxation of Smooth Muscle
Why does Plasma Volume increase in Pregnancy? What happens as a result?
Increased RAAS stimulation increasing salt and water reabsorption
Gestational Anaemia due to reduced haematocrit
State four respiratory changes in Pregnancy
Tidal Volume increases
Minute Ventilation increases by around 15%
Hyperventilation resulting in Resp Alkalosis
Vascular Engorgement (Nasal Stuffiness, Nose Bleeds)
State four Maternal changes to GI System in Pregnancy
Relaxation of Smooth Muscle (Heart Burn, Constipation, Biliary Tract Stasis - Gall Stones)
Upward displacement of Stomach
Appendix may move to RUQ
High bHCG may cause morning sickness
State three Renal Maternal Adaptations in Pregnancy
GFR increased by around 55% (due to increased plasma volume)
Smooth Muscle Relaxation causes Hydronephrosis/Hydroureters
Increased risk of UTI
State three Haematological changes in Pregnancy
Increase in Fibrinogen/Clotting Factors
Increased Venous Stasis/Venodilation
Gestational Anaemia
Describe the two different types of nutrition during foetal life
Histiotrophic - up to 12th week (not from maternal blood)
Haemotrophic - after 12th week (from maternal blood)
Where is Brown Fat stored?
Around neck
Behind Scapulae
Sternum
Around Kidneys
How should the foetus appear at 12 weeks?
Skin translucent
Reactant to stimuli
External Genitalia undifferentiated
How should the foetus appear at 16 weeks?
CRL of 122mm
External Genitalia now distinguishable
How should the foetus appear at 24 weeks?
CRL is 210mm
Eyelids separated
Skin Opaque
How should the foetus appear at 28 weeks?
Eyes are open
Scalp growing hair
What is the Embryonic vs Gestational Age?
Embryonic - time since fertilisation
Gestational - Time since LMP (ie: Embryonic + 2 weeks)
Describe the three periods of foetal development
Germinal Stage - first two weeks
Embryonic Period - Start of third to end of 8th week
Foetal Period - Start of 9th until birth
Describe the 6 stages of placental development
1) Blastocyst hatches and dedidual reaction occurs
2) Trophoblast differentiates into Cytotrophoblast and Syncytiotrophoblast
3) Lacunar network of maternal spiral arteries forms in Syncytiotrophoblast, Primary Chorionic Villi form (Inner Cytotrophoblast invading Outer Syncytiotrophoblast)
4) Mesenchyme core develops in villi (secondary chorionic villi)
5) Which then develops into blood vessels (tertiary chorionic villi)
6) Throughout the latter trimesters the barrier thins and Cytotrophoblast is lost
What are the two parts of the placenta?
Maternal - Decidua Basalis
Foetal - Chorion Frondosum
How does the placenta appear at full term?
15-25cm
500-600g
What is the Umbilical Cord?
Paired Arteries and a Vein embedded in Wharton’s Jelly
State a substance that is transported across the placenta by simple/active and facilitated transport respectively
Simple - Oxygen
Active - Amino Acids
Facilitated - Glucose
What is the endocrine function of the Placenta?
hCG to maintain corpus luteum
Produced Oestrogen and Progesterone to maintain pregnancy from 4th month
HPL
How do you calculate EDD
LMP + 1 year and 7 days, minus 3 months
State four signs you might see on Inspection in an Obstetric Exam
Linea Nigra (pigmented line from Xiphisternum to Suprapubic)
Striae Gravidarum (new, purple)
Striae Albicans (old, white)
Flattening/Eversion of Umbilicus
State five features of palpation on an Obstetric Examination
Symphysis Fundal Height (able to measure this from 20 weeks)
Estimation of Foetal Number
Foetal Lie
Presentation
Amniotic Fluid Volume
How would you listen the Foetal heart in an Obstetric Examination?
From 16 weeks - Doppler USS, Sonicaid
From 28 weeks - Foetal Stethoscope
State 6 symptoms of Pregnancy
Amenorrhoea
Morning Sickness
Increased Micturition Frequency
Excess Fatigue
Breast Tenderness
Pica
Describe the pattern of hCG in Pregnancy
Increases exponentially from day 8
Peaks at 8-12 weeks
Home (Urine) Kits are sensitive to levels >50IU/L
How is a pregnancy dated?
Via the Dating scan between 8-13 weeks, using CRL
What else should be offered at the dating scan (if not already)?
Urine screen for Pre- Eclampsia
Haemoglobinopathy screen
Rhesus screen
Downs Syndrome Screen
When would you carry out the Structural Anomaly Scan? Y
Between 18-20 weeks
What should be done at the 28 week scan?
Another opportunity for Anaemia/ Atypical Antibody screening
Anti D Prophylaxis if Rhesus Negative
Measure BP/Proteinuria/SFH
When should you offer a second dose of Anti D?
At 34 weeks
What Supplements does a Pregnant Woman require?
Folic Acid - 400mcg/d for the first 12 weeks to minimise risk of neural tube defects
Iron/Iodine - only if deficient area
Zinc&Calcium - if dairy free
Vitamin A - can be teratogenic if >700mcg/d
She requires an extra 350kcal a day
Name four foods a pregnant woman should avoid
Pâté
Soft Cheeses
Raw Fish
Unpasteurised Milk
Other than CRL, name four other USS measurements
Biparietal Diameter
Head Circumference
Abdominal Circumference
Femur Length
Define ‘Small for Gestational Age’
Infant with weight <10th centile for its gestational age
State the three types of Small for Gestational Age
Normal/Constitutionally Small (growing at a normal rate but just small)
Placenta Mediated Growth Restriction (Normal growth that initially slows due to placental insufficiency - substance abuse/autoimmune/diabetes/ renal disease)
Non Placenta Mediated Growth Restriction (Chromosomal/Structural Abnormalities)
Give three minor and three major risk factors for ‘Small for Gestational Age’
Minor - Nulliparity, Previous Pre - Eclampsia, Low fruit intake pre pregnancy
Major- Smoker>10 per day, Maternal Age>40, Previous SGA baby
How would you investigate a suspected SGA baby?
Ultrasound Scan
Uterine Artery Doppler
Karyotyping
Why is the ratio of HC:AC important in SGA babies?
If constitutionally small, they are likely to be similar
If placental insufficiency it’s likely to be asymmetrical/head sparing
How often should an SGA baby be monitored?
At least every 14 days
When should an SGA be delivered by C Section before 37 weeks?
If Absent Doppler or Reverse End Diastolic
State four complications of SGA baby
Asphyxia
Hypothermia
Cerebral Palsy
Precocious Puberty
Give three examples of sensitising events with Red Cell Isoimmunisation
Antepartum Haemorrhage
Abdominal Trauma
Delivery
What is Anti-D and when should it be given?
Binds to Rhesus D Antibodies preventing immune response
Should be given after ANY sensitising event in Rhesus Negative Women
Even if no sensitising event, should be given at 28 and 34 weeks in Rhesus Neg Women
What is the Fetomaternal Haemorrhage test?
Assesses how much foetal blood has entered maternal circulation
If occurring after 20 weeks it is used to assess how much Anti D is required
What sort of sensitising events could occur before 12 weeks?
Ectopic Pregnancy
Molar Pregnancy
Termination of Pregnancy
Heavy Bleeding
Define Prematurity
Delivery between 24 and 37 weeks gestation
(Very preterm is <32 weeks)
What is PPROM (Preterm Prelabour Rupture of Membranes)?
Rupture of foetal membranes before 37 weeks and before labour onset
Give 5 associations of prematurity
Multiple pregnancies
Foetal Growth Restriction
Iatrogenic
Cervical Incompetence
Systemic Maternal Infection (bacterial toxins initiate inflammatory response and release of prostaglandins)
Name three ways you can identify women at risk of prematurity
Clinical Risk Scoring (smoking status, socioeconomic, pmh)
Cervical Assessment - short is high risk
Foetal Fibronectin (maintains placental decidual matrix)
Give three ways that you could PREVENT preterm labour
Antibiotics
Cervical Cerclage (purse string)
Progesterone (Antagonises Oxytocin, Anti Inflamm, Maintains Integrity)
How can you INHIBIT pre term labour (AKA Tocolysis)?
Nifedipine
Oxytocin Antagonist (Atosiban)
COX Inhibitors (may cause problems with DA as required to be patent)
What is Prolonged Pregnancy?
Refers to the 5-10% of pregnancies persisting beyond 42 weeks gestation
Give three clinical features of prolonged pregnancy
Macrosomia
Reduced foetal movement
Meconium
How would you manage Prolonged Pregnancy?
Membrane sweeps 40 weeks in nulliparous and 41 weeks in parous
Induction of labour between 41 and 42 weeks
Any signs of placental insufficiency- deliver
Define Miscarriage
The loss of pregnancy at less than 24 weeks gestation (early - before 12 weeks)
Does not include Ectopic/ GTD
What are the 6 classifications of Miscarriage
Threatened - USS is viable
Inevitable - likely to proceed to complete/incomplete
Missed (Early Foetal Demise)- No foetal heart beat when CRL>7mm
Incomplete - POC partially expelled
Complete - No POC on USS
Septic - Infected POC
How might a Miscarriage present?
Vaginal bleeding (may be passing clots or POC)
Suprapubic Cramping
May have annexal masses/collections
What imaging would you use to investigate a Miscarriage?
Transvaginal Ultrasound
If CRL>7mm and Gestation 5.5-6.5 weeks, a feral heartbeat should be heard
If foetal pole not visible, confirmed presence with gestational and yo,m sac (if greater than 25mm - likely miscarriage)
What would the bloods of a Woman who has just miscarried show?
Declining Serum b-HCG
Low Progesterone
Describe the conservative/expectant management of Miscarriage, it’s advantages and disadvantages
Anti D and Allow POC to pass naturally, repeat scan in two weeks/pregnancy test three weeks later
Advantages: can remain at home, no anaesthetic or surgical risk
Disadvantages: unpredictable, heavy bleeding, chance of failure
Describe the Medical management of a miscarriage, it’s advantages and disadvantages
Uses Misoprostol (PG Analogue) to stimulate cervical ripening and myometrial contractions
Advantages: Can be done at home, avoids surgical/anaesthetic risk
Disadvantages: Vomiting, Heavy Bleeding/ Pain, chance of requiring op
Describe the surgical management of a Miscarriage, it’s advantages and disadvantages
If under 12 weeks, manual vacuum aspiration with local anaesthetic. If over 12 weeks, evacuation of retained products of conception under GA
Advantages: Planned Procedure, Unaware During
Disadvantages: Anaesthetic risk, Perforation, Haemorrhage, Ashermans
When is surgical management of Miscarriage indicated?
Haemodynamically Unstable
Infected Tissue
Gestational Trophoblastic Disease
Define Recurrent Miscarriage
Occurrence of three or more consecutive pregnancies that end in the miscarriage of the foetus before 24 weeks
State 5 causes for Recurrent Miscarriage
Antiphospholipid Syndrome
Genetic Abnormalities (eg Robertsonian)
Endocrine (PCOS, Thyroid Disease, DM)
Anatomical (Uterine Malformations, Ashermans)
Inherited Thrombophilias
Give 3 risk factors for recurrent miscarriage
Advancing Maternal Age
Number of Previous Miscarriages
Smoking
Name three investigations for recurrent miscarriage
Bloods (Lupus/Anti Cardiolipin/Anti B2 Glycoprotein/Inherited Thrombophilia Screen)
Karyotyping (can test parents if foetus comes back abnormal)
Pelvic USS
Describe the genetic counselling given to women suffering from recurrent miscarriage
Offers prognosis for future pregnancies
Offers other reproductive options
If the cause of the recurrent miscarriage is Cervical Weakness how would you manage?
Cervical Cerclage
If the cause of the recurrent miscarriage was Antiphospholipid Syndrome, how would you manage?
Low dose Aspirin (from positive pregnancy test)
LMWH (from foetal HB)
What is an Ectopic Pregnancy?
One occurring anywhere outside the uterus (most commonly ampulla and isthmus)
Can coincide with Intrauterine Pregnancy - Heterotropic Pregnancy
What is a Cornual Pregnancy?
Pregnancy in the rudimentary horn of the uterus (technically uterine but ectopic)
Give 5 risk factors for Ectopic Pregnancy
Previous Ectopic
PID
Endometriosis
Progesterone only contraception (alters fallopian ciliary motility)
Assisted Reproduction
How would a (non ruptured) Ectopic Pregnancy present?
Pelvic Pain
Vaginal Bleeding (due to reduced HCG)
Shoulder tip pain
Brown vaginal discharge
How would a ruptured Ectopic Pregnancy present?
Haemodynamically unstable
Peritonism
Fullness in PoD during Vaginal Exam
Give 3 differentials for an Ectopic Pregnancy
Miscarriage
Ovarian Torsion
Acute PID
How would you investigate a suspected Ectopic Pregnancy?
1) Pregnancy Test
2) Transvaginal USS (if nothing is seen then it is termed Pregnancy of Unknown Location)
What is Pregnancy of Unknown Location and how can you investigate?
Could be an ectopic, a very early intrauterine pregnancy or a miscarriage
If serum HCG>1500 IU - Offer diagnostic laparoscopy
If serum HCG<1500 IU - as long as patient is stable, do repeats (miscarriage halves every 48hrs, viable doubles)
How are Ectopic Pregnancies managed medically?
IM Methotrexate - disrupts folate metabolism causing pregnancy to resolve, may require repeat dose
Remains teratogenic so should not aim to conceive for the following 6 months