Obstetrics Flashcards
What technique is used to help deliver a baby with shoulder dystocia vaginally?
McRoberts manoeuvre
What is shoulder dystocia?
Where the baby’s shoulder gets stuck (usually on the mother’s pubic symphysis) after the head is delivered.
What are the risk factors for shoulder dystocia?
- Foetal macrosomia
- High maternal body mass index
- Diabetes mellitus
- Prolonged labour
What are the normal Hb levels for pregnant women?
- First trimester Hb > 110 g/l
- Second/third trimester Hb > 105 g/l
- Postpartum Hb > 100 g/l
After 24 weeks, how much would you expect the fundal height to grow each week?
1 cm
At what gestation is chorionic villous sampling done?
11 to 13 weeks
What is the first line investigation for pre-term rupture of membranes?
Speculum exam
What Bishop’s score indicates that spontaneous labour is likely?
> 8
What is a normal foetal blood pH in labour?
> 7.2
When should magnesium sulphate treatment be stopped in the treatment of pre-/eclampsia?
24 hours post- delivery OR her last seizure, whichever is later
What are the neonatal signs of Down’s syndrome?
- Hypotonia
- Umbilical hernia
- Flattened face
- Large protruding tongue
What treatment should be given to a newborn baby when her mother is Hep B +ve and has surface antigens?
Hep B vaccine and 0.5mls of HBIG within 12 hours of birth with a further hepatitis vaccine at 1-2 months and a further vaccine at 6 months
What are the SSRIs of choice for breastfeeding women?
- Sertraline
- Paroxetine
At what gestation can pre-eclampsia be diagnosed?
20 weeks
What is vasa praevia?
Where foetal blood vessels cross or run near the internal orifice of the uterus
What is the classic triad of vasa praevia?
1) Vaginal bleeding
2) Denies any pain
3) Foetal bradycardia
What is the main clinical feature of placenta previa?
Painless fresh bleeding after 24 weeks gestation
What normally happens to blood pressure during pregnancy?
It falls in the first half of pregnancy and before rising to pre-pregnancy levels before term
What abnormal blood results would you see in a woman with hyperemesis?
- Hyponatraemia
- Hypochloraemia
- Elevated urea
- Decreased TSH, normal T4
- Raised ketones
What is the RCOG definition of severe hyperemesis gravidarum?
Severe, protracted nausea and vomiting associated with weight loss of more than 5% of pre-pregnancy weight, dehydration and electrolyte imbalances.
The contraceptive implant can be inserted ________ after childbirth.
Immediately
What is the greatest risk factor for cord prolapse?
Artificial rupture of membranes
What is the transverse lie foetal position?
Where the foetal longitudinal axis lies perpendicular to the long axis of the uterus.
What is the management when a foetus is in the transverse lie positions?
- 1st attempt external cephalic version
- If ECV fails deliver via C-section
How do you calculate the expected delivery date?
One year and 7 days after the last menstrual period minus three months
At what gestation can you start to feel the uterus via the abdomen?
12 weeks
By __ weeks, the fundus of the uterus lies halfway between the symphysis pubis and the umbilicus.
16
What indicates that babies are small for their gestational age?
If the SFH is >1-2cms outside normal ranges
At what stage of pregnancy does the linea nigra darken?
First trimester (13 weeks)
When should the mother start to feel foetal movements?
18-20 weeks
What is the expected development of foetal movements throughout pregnancy?
They start at 18-20 weeks, increase in frequency up to 32 weeks then plateau to an average of 31/hour
Where is progesterone synthesised during pregnancy?
The corpus luteum until 35 days post-conception and then mainly the placenta
What is the function of progesterone during pregnancy?
- Decreases smooth muscle excitability
- Raises body temperature
What is function of oestrogens during pregnancy?
- Increase breast and nipple growth
- Water retention
- Protein synthesis
Why does vaginal discharge increase during pregnancy?
- Cervical ectopy
- Cell desquamation
- Increased mucus production from a vasocongested vagina
Why are pregnant women physiologically anaemic?
Because their plasma volume increases by 50% and their red cell volume only rises from between 18-30%. Therefore, Hb falls due to dilution.
What blood markers are raised during pregnancy?
- Red cell volume
- White cell count
- Platelets
- ESR
- Cholesterol
- β-globulin
- Fibrinogen
What blood markers decrease during pregnancy?
Urea and creatinine
Describe the latent phase of labour.
The first part of the first stage of labour. Painful, irregular contractions, the cervix effaces (becomes shorter and softer) then dilates to 4cms
How long does the latent phase of labour last? What is the difference between primips and multips?
8-18 hours in primips
5-12 hours in multips
Describe the established phase of labour.
This is the second part of the first stage of labour. Regular contractions with cervical dilation from 4cms. The cervix should be dilating 0.5cms/hour
Describe the passive stage of labour.
The first part of the second stage of labour where the cervix is fully dilated but the mother is not pushing.
Why is 1-2 hours in the passive stage recommended for women with epidural anaesthesia?
To reduce the chance of an instrumental delivery
Describe the active stage of labour.
The second part of the second stage of labour where the mother is actively pushing
Why do you apply pressure over the perineum when the baby’s head is being delivered during labour?
To prevent a rushed delivery and therefore reduce the risk of intracranial bleeding.
Describe the third stage of labour.
This is the delivery of the placenta
What is the management of antiphospholipid syndrome?
- Low dose aspirin as soon as +ve urine pregnancy test
PLUS - Low molecular weight heparin once heartbeat seen on ultrasound
Why is co-amoxiclav not given to a patient after PROM?
It may increase the risk of NEC in neonates
What is the management of PROM?
- Antibiotics, oral erythromycin or a penicillin
- Corticosteroids, IM betamethasone or dexamethasone
At what gestations are corticosteroids given to women with PROM?
24 to 35+6 weeks
What happens to peripheral resistance during pregnancy?
Falls due to hormonal changes
What techniques can be used to avoid/minimise aortocaval compression?
Placing the woman in the left lateral position or by tilting 15 degrees go the left
What hormone causes an increased tidal volume in pregnancy?
Progesterone
Why is breathlessness common during pregnancy?
Because material PaCO2 is set lower to allow the fetus to off-load CO2.
Babies conceived __-__ ________ after a live birth have the lowest rate of perinatal problems.
18-23 months
What vaccination do you need to ensure that mother have had during pre-pregnancy counselling?
Rubella
How much folic acid should a healthy woman have and when?
0.4mg daily >1 month preconception until 13 weeks
What women should have 5mg of folic acid per day?
- Past NTD
- On anti-epileptics
- Diabetic
- Obese (BMI >30)
- HIV +ve on co-trimoxazole prophylaxis
- Sickle cell disease
What should pregnant women avoid consuming?
- Liver
- Vitamin A
- Undercooked meat
- Pâté
- Soft cheeses
- Shellfish
- Raw fish
How much alcohol can pregnant women drink per week?
1-2 units
What maternal antibodies cross the placenta?
IgG
What are the functional units of the placenta?
Placental villi
What is the cause of pre-eclampsia?
When the trophoblast invasion of the placenta is too shallow and there is no progress beyond the superficial portion of the uterine spiral arterioles. This causes these spiral arterioles to retain their endothelial linings and remain narrow, high-resistance vessels resulting in poor material flow. Maternal BP then rises to compensate for this.
How many umbilical arteries are there and what do they carry?
2
Deoxygenated blood from the foetus to the placenta
How many umbilical veins are there and what do they carry?
One
Oxygen and nutrient rich blood from placenta to the foetus
What are the criteria for pregnancy morbidity?
- The loss of three or more embryos before 10 weeks
- One unexplained foetal death beyond 10 weeks
- Premature birth of a healthy child before 34 weeks as a result of eclampsia, severe pre-eclampsia, intrauterine growth restriction or placental insufficiency
What is obstetric antiphospholipid syndrome?
Female patients with antiphospholipid antibodies and a history of pregnancy-related morbidity but no history of thrombosis
What is colostrum?
A form of breast milk secreted in the first 2-3 days after delivery. It is rich in WBCs and antibodies, especially IgA, and contains larger proportions of protein, minerals and vitamins A, E and K
What hormones are involved in breastfeeding? What is their role?
Prolactin = ensures secretion of milk by the alveolar cells in the breast
Oxytocin = causes myoepithelial cells around the alveoli to contract causing the milk to flow along the ducts
What hormonal changes occur after birth that allow breastfeeding to occur?
Progesterone and oestrogen, that were previously inhibiting prolactin, rapidly decrease allowing milk to be produced
What is Sheehan’s syndrome?
Pituitary apoplexy during or immediately after childbirth
