Intro To Obstetrics

Question 1

Define Menarche

Answer 1

Age at first menstrual period

Question 2

Define LMP
What is it’s significance?

Answer 2

Last Menstrual period: First day of the last menstrual period

It is used to estimate the date of delivery, assuming ovulation occurs at day 14, using Naegele’s rule

Question 3

What is EDD?

Answer 3

Estimated Date of Delivery

Question 4

How do you calculate EDD?

Answer 4

Naegele’s rule
=> EDD = LMP + 9 months + 7 days

Question 5

What is the EDD of May 22, 2024

Answer 5

March 1, 2025 if not a leap year. February 29 if it was a leap year

Question 6

If your last menstrual period is today and you know youre getting pregnant at just the perfect time, what is your EDD?

Answer 6

Naegele’s rule
=> EDD = LMP + 9 months + 7 days

Question 7

What is meant by index pregnancy?

Answer 7

Current pregnancy/pregnancy in question

Question 8

Define Viability

Your colleague is handing over a patient to your care and says they are G3P1+1.
Please define each component

Answer 8

Viability = Capacity for a foetus to survive => a foetus reaching 24 weeks of gestation and/or 500g estimated weight

G3 = Gravidity = # of pregnancies including the index pregnancy. This woman is now in her 3rd pregnancy

P1 = Number of !prior pregnancies that have reached viability

+1 = # of pregnancies that did not reach viability

=> Woman preganant for the 3rd time, has 2 baby, and 1 non-viable pregnancy

Question 9

Using gravidity and parity, describe a woman who is in the labour ward and previously had given birth to twins via C-section. She has terminated a pregnancy in her teens medically due to it being an unwanted pregnancy.

Answer 9

G3P1+1
We only count the # of pregnancies not the number of babies

Question 10

What are the 2 main methods of estimating the date of delivery? When are they performed?
Which one should we go by when informing a patient their EDD?

Answer 10

During their booking visit, all women will receive an US to confirm their gestational age and compare it to their LMP-derived EDD

We use the US-derived EDD if the booking visit occurs b/w:
6-12 weeks + discrepancy of 5 or more days
14-20 weeks + Discrepancy of 7 days or more
Otherwise use LMP as the US becomes less reliable in the 2nd and 3rd trimesters

Question 11

How do you calculate the ED using US?

Answer 11

Crown-Rump Length (CRL)

Question 12

A patient does not remember when their last period was. How would you determine their EDD. There are no US probes in the hospital, Deal with it

Answer 12

Ask for their first +ve pregnancy test and !!specifically if it was preceded by a -ve test

Commercial tests are typically positive a few days before the patient’s first missed periods. Combine that with the regularity of their menstrual cycle.

Question 13

Outline using only headings, what you would ask in an obstetric hx

Answer 13

1 - Introduction
2 - PC and hx of PC
3 - Hx of pregnancy to date
4 - Obstetric Hx
5 - Gynaecological Hx
6 - PMHx + PSHx
7 - Medication and Allergy
8 - Fam Hx
9 - Social Hx
10 - Systems Review

Question 14

What should you always start receiving during the introduction part of your hx

Answer 14

Introduce self and gain consent
Name, age, G, P, GA
Are you in pain today/ Are you seated comfortably?

Question 15

How would you assess the patient’s pregnancy to date when taking a history?

Answer 15

1) LMP + EDD (or calculate it)
2) GA when booked in for prenatal care + booking bloods (anything unusual?)
3) Folic acid supplements (When did you start taking)
4) Test for Foetal Abnormalities (NIPT or Amniocentesis)
5) Foetal Anatomy scan (Had they told you anything regarding the scan? Placental location if previous CS or APH admission)
6) Problems or Hospital Admissions to date

Extra = Type of antenatal care (Hospital vs Midwifery vs Combined)

Question 16

How would you go over a patients past Obstetric Hx?

Answer 16

1) Ask about other children:
Age, name, GA, Mode of delivery, Birthweight, Health at birth (NICU?)

2) Previous complications during pregnancy/on delivery/after delivery.

3) Any early pregnancy losses?

Question 17

What factors may affect the accuracy of LMP-derived EDD? (2)

Answer 17

Recent breast feeding
OCP (Hormonal contraception)

Question 18

While taking a history of an obstetric patient, what would you go over in terms of their gynaecological history?

Answer 18

1) Cycle: LMP, Menarche, regularity, IMB (described as for e.g. 5/28)

2) Smear: When? Was it normal? Up to date with screening protocol? (Every 3 or 5 years)

3) Contraception (how long ago was it stopped?)

4) Previous gynaecological problems along with their investigations and tx

Question 19

How long should a woman cease from taking hormonal therapy for the EDD to be accurately calculated based on LMP?

Answer 19

3 months

Question 20

Define Ectopic pregnancy

Answer 20

Pregnancy implanted outside the uterine cavity

Question 21

What is ERPC?

Answer 21

Evacuation of Retained Products of Conception

Used in cystocele

Question 22

What range of dates is considered neonatal death?

Answer 22

Death within 28 days

Question 23

Define Stillbirth

Answer 23

A baby delivered > 24 weeks or >500g showing no signs of life

Question 24

A gynaecology patient tells you that they’ve had LSCS in their surgical history. What is LSCS?

Answer 24

Lower segment caesarean section

Question 25

What is the definition of Antepartum hemorrhage?

Answer 25

Haemorrhage after viability (>24 weeks) until labour

Question 26

What must you screen for whenever you are taking someones past medical and family hx?

Answer 26

CVD
HTN
Thyroid
VTE
Diabetes
Seizure risk
Gynaecological or bowel cancers

Question 27

Spot Diagnosis:
Renal disease, chronic HTN in a nulliparous woman

Answer 27

Preeclampsia

Question 28

Spot Diagnosis:
Seizures, Renal disease, chronic HTN, Nulliparity

Answer 28

Eclampsia
OR
Mother has CKD with hx of seizures
OR
History of seizures and Pre-eclampsia

Question 29

How would you go over social hx in Obs&Gynae

Answer 29

1) Support System: Married/Single, Support at home, Who is looking after children while you’re here

2) Occupation (outside house, strenuous, wfh)

3) Smoke/drink/recreational drugs

4) Feeding plan (Breast vs bottle)

Question 30

Rubella is one of the major viruses tested for when booking bloods. There is a 51% chance that the foetus would be infected as well if infection occurs in what trimester? State the weeks associated with that trimester.

State the Triad for congenital Rubella infection (sx)

Answer 30

1st Trimester 0-12 weeks

1) SNHL/Deafness
2) Eye abnormalities (cataracts and micropthalmia)
3) CHD specifically ductus arteriosis

Question 31

During what trimester is thefoetus most prone to teratogenic agents?

What are the 3 categories of teratogenic agents? Give examples

Answer 31

First trimester 0-12 weeks

Medications: ACE inhibitors, Warfarin, Lithium, Isotretinoin, Temazepam, Thalidomide

Infections: TORCH + Parvovirus B19

Imaging: Ionising radiation

Question 32

What is the role of Folic acid in preganancy?
how would you advise the mother to take folic acid at Pre-conception counseling? (Including dosing)

Answer 32

Folic acid should be taken 3-months pre-conceptually and throughout the first trimester (0-12 weeks) to reduce the incidence of neural tube defects such as spinal bifida. If the patient is on certain medicatins such as sodium valproate or has a hx of spinal bifida in family or a diabetic, you would dose the patient at 5mg. Otherwise 0.4mg would be recommended daily.

Question 33

Maternal blood has hemoglobin with 2 alpha and 2 bets chains whereas foetal has 2 alpha and 2 gamma chains. What is the significance of that in pregnancy?

Answer 33

CO2 in foetal circulation binds to a lesser extent than maternal circulation => CO2 can be passed on to the maternal Hb (with higher affinity to O2) => mother can ventilate for foetus.

Question 34

What sympathetic fibers innervate the pelvis?
Where do the parasympathetic ganglia of the pelvis lie?
What nerve is responsible for innervation of the perineum?

Answer 34

Sympathetic fibres arise from T12 and L1.
Parasympathetic ganglia lie on the anterior surface of the sacrum
Pudendal nerve S2,S3,S4

Question 35

True or False. Viability is considered at 25 weeks gestation/500g.

Answer 35

Viability is at 24 weeks gestation/500g.

Question 36

At the start of every examination, until palpation what should you do

Answer 36

Wash hands, Introduce, ask about pain, explain the examination to the patient, and expose the patient appropriately.
!! Check vital signs, take BP, look at observation chart and say you will update it accordingly. Check Urinalysis.

Then General Inspection…

Question 37

How would you take the patient’s BP?

Answer 37

BP is taken in the semi-recumbent position (30 degrees) from the right arm with a correctly fitted cuff

Question 38

On general inspection of the abdomen in an obstetric patient, what would you be looking for?

Answer 38

Distended abdomen consistent with pregnancy/high BMI/oedema…
Inverted/Umbilical
Striae gravidarum
Linea Nigra
Scars
Ecchymosis

Question 39

What are Linea Nigra?

Answer 39

Midline hyperpigmentation

Due to melanocyte-stimulating hormone produced by placenta

Question 40

Spot differentials for the following Urinalysis results:
Proteinuria:
Glycosuria:
Hematuria:
Leukocytosis:

Answer 40

Proteinuria: Pre-eclampsia dx, renal disease
Glycosuria: DM/GDM
Hematuria: UTI, renal colic, renal disease
Leukocytosis: UTI diagnosis (+nitrites as well)

Question 41

Normal range for symphysial-fundal height?

Answer 41

GA +/-2

Question 42

The manœuvres including fundal, lateral and pelvic grips are called?

Answer 42

Leopold Manœuvres

Question 43

Devices used for auscultation of foetal HR?

Answer 43

Pinard
Doppler
US pelvis
CTG (not auscultation)

Question 44

What examination findings would suggest a DVT?

Answer 44

UNILATERAL
Erythema, pain, swelling, heat

Question 45

After completing a patient’s obstetric exam, you check the lower limbs for?

Answer 45

Oedema, varicose veins, and evidence of DVT

Question 46

When would you opt to do a neurological examination on an obstetric patient?

Answer 46

Previous history of focal neurological disease
Actual answer: Pre-eclampsia patients to assess for the presence of eclampsia

Question 47

How would you confirm SROM in a patient who is not sure?

Answer 47

1) Vaginal examination -> pooling of amniotic fluid in the posterior fornices
2) Amniosure -> paper that determines presence of amniotic fluid
3) pH Litmus test -> Red->blue, Blue->blue => basic pH

Question 48

What are the indications for a vaginal examination? (5/6)

Answer 48

To confirm SROM
Vaginal bleeding
Assess cervical dilatation + effacement + favourability for induction
Confirm + Assess progress in labour

Question 49

how would you assess the patient’s favourability for induction? Go into detail of scoring including interpretation of results

Answer 49

Bishop scoring
>7 Spontaneous delivery likely => no need for induction
<7 Spontaneous delivery unlikely => induction necessary

Question 50

Who receives pre-conception counselling?

Answer 50

Any woman contemplating pregnancy

Question 51

What type of scar is associated with a C-section

Answer 51

Pfannestiel scar

Question 52

On examination of an obstetric patient, you notice some ecchymosis. What would be the most likely cause of it?

Answer 52

Medications: Innahep and Insulin injected subcutaneously
Others = cullen’s sign from hemorrhagic pancreatitis and AAA

Question 53

How would you describe distension associated with pregnancy?

Answer 53

Ovoid distension

Question 54

What dietary advice would you give a woman contemplating pregnancy?

Answer 54

Balanced diet, weight optimisation (RF), avoidance of:
Listeriosis: Meats, soft cheeses, pates)
Salmonella: Red meats, runny eggs, petting animals
Taxoplasmosis: Gloves when gardening, hand hygeine

Question 55

What general advice would you give all mothers contemplating pregnancy in terms of general pre-conception counselling?

Answer 55

1) Dietary: Balanced diet, weight optimization, avoidance of Listeriosis (meats, soft cheeses, pates), Salmonella (avoid runny eggs, red meats, petting farm animals), Taxoplasmosis (Gloves when gardening)

2) Folic acid: Folic acid should be taken 3-months pre-conceptually and throughout the first trimester (0-12 weeks) to reduce the incidence of neural tube defects such as spinal bifida. If the patient is on certain medicatins such as sodium valproate or has a hx of spinal bifida in family or a diabetic, you would dose the patient at 5mg. Otherwise 0.4mg would be recommended daily.

3) Avoidance of smoking, alcohol, and recreational drug use

4) Check all medications with pharmacist to ensure that there are no effect on pregnancy. Also ensure compliance of medicaitons.

5) Advise on risk of foetal abnormalities

Question 56

Briefly outline the process between the woman having a positive commercial pregnancy at home until delivery

Answer 56

Care is initiated by the GP who will confirm the pregnancy via Beta HCG and writes to the hospital to request a registration or “Booking visit”. This should ideally be done in the first trimester.

At the booking visit:
1) Hx taking and discussion with midwife
2) EDD calculated by LMP using Naegele’s rule
3) Obstetric examination
4) Booking bloods
5) Early Ultrasound
6) If medical disorder, consult with respective team -> Specific surveillance plan
7) If high risk, consult with anaesthesia and have hospital-based consultant-led pre-natal care

Question 57

When is the uterus palpable?

Answer 57

12 weeks (end of first trimester)

Question 58

What is included in the standard booking bloods?

What is added to that for select patients (high risk)

Answer 58

1) FBC
2) Blood group + Red cell alloantibody screen + RhD status
3) Infections: Rubella, Syphilis, HIV, Hep B (varicella done but not routine. It is done to save incase the patient comes into contact with varicells)
4) Discuss fetal aneuploidy

1) Hemoglobin Electrophoresis for those with ethnicities such as those at risk for Thalassemia (east asian), and Sickle cell (African)
2) Infections: Hep C, Parvovirus IgG, Taxoplasmosis.
3) Fetal Aneuploidy (if agreed)