Obstetrics and Gynaecology Flashcards
Name 3 hormones that are important in pregnancy.
Main hormones:
- hCG.
- Progestins.
- Oestrogens.
Other hormones:
- hPL.
- Prolactin.
- Oxytocin.
Where is hCG produced?
The trophoblast.
Give 2 functions of hCG.
- It signals the presence of the blastocyst.
2. It prevents the corpus luteum from dying - luteal regression.
Where are progestins produced?
Initially from the corpus luteum and then from the placenta from week 7.
Give 3 functions of progestins.
- Prepares the endometrium for implantation.
- Promotes myometrial quiescence.
- Increases maternal ventilation.
How do progestins prepare the endometrium for implantation?
Progestins stimulate the proliferation of cells, vascularisation and the differentiation of endometrial stroma.
Where are oestrogens produced?
Initially in the ovary and then from a combination of fetal and maternal sources.
Give 2 functions of oestrogens in pregnancy.
- Promotes a change in the CV system.
2. Alters carbohydrate metabolism.
What is the main oestrogen in pregnancy?
E3 - it indicates fetal well-being.
What is the role of E2 in pregnancy?
E2 is responsible for proliferation of the endometrial epithelium. It also facilitates progesterone action.
What is the role of human placental lactogen (hPL)?
- Mobilises glucose from fat.
- Acts as an insulin antagonist.
- Converts mammary glands into milk secreting tissues.
What is the role of prolactin?
Prolactin is responsible for milk production.
What is the role of oxytocin?
Oxytocin is responsible for milk secretion and uterine contractions.
Where is prolactin produced?
In the anterior pituitary gland.
Where is oxytocin produced?
In the posterior pituitary gland.
Where are FSH and LH produced?
In the anterior pituitary gland.
What hormone does the hypothalamus release that acts on the anterior pituitary gland and stimulates the production of FSH and LH?
GnRH.
What cells in the ovaries does FSH act on?
Granulosa cells -> oestrogen production.
What cells in the ovaries does LH act on?
Theca cells -> androgen production.
What hormone is released from the hypothalamus that acts on the anterior pituitary to inhibit prolactin release?
Dopamine.
What is the principle foetal nutrient?
Glucose.
Can the foetus produce any of its own glucose?
No, gluconeogenic enzymes are inactived in the foetus and so all its glucose has to come from its mother.
In early pregnancy, is plasma glucose high or low?
Plasma glucose is lower because glucose is being stored.
Why is plasma glucose lower in early pregnancy?
Because the mother is storing glucose.
In late pregnancy, is plasma glucose high or low?
Plasma glucose is higher. This is due to maternal insulin resistance and glucose sparing for the foetus.
Why is plasma glucose higher in late pregnancy?
- Because of increasing maternal insulin resistance.
2. Glucose sparing for the foetus.
What are the consequences of maternal insulin resistance?
Maternal insulin resistance -> gestational diabetes -> increased risk of macrosomia and shoulder dystocia.
Why is the immune response suppressed in a pregnant lady?
It prevents foetal rejection.
Give 4 ways in which foetal rejection is prevented in a pregnant lady.
- A TH2 bias is observed.
- Syncytiotrophoblast has no self:non-self markers and so doesn’t stimulate an immune response.
- Extra-villous trophoblast cells have modified markers.
- The overall immune response is suppressed.
In a normal pregnancy, a TH2 bias is observed, this helps prevent foetal rejection. Give 3 potential consequences if there is not a TH2 bias.
- Pre-eclampsia.
- IUGR.
- Miscarriage.
How does the endometrial epithelium become adhesive to the blastocyst?
The blastocyst and endometrium communicate via the release of hormones -> ‘sticky endometrium’.
When in a woman’s cycle does the endometrium become sticky?
This usually happens between days 20-24. This is called the window of implantation and outside of this time implantation will not occur.
What reaction occurs when a blastocyst implants into the endometrium?
A primary decidual reaction occurs.
What part of the blastocyst facilitates placental formation?
The cytotrophoblast.
Placenta formation: What does the cytotrophoblast go on to form?
Anchoring villi -> extra villous trophoblast.
Floating villi are also involved.
What can trigger the differentiation of anchoring villi into extra-villous trophoblast?
Hypoxia.
What is the role of extra villous trophoblast (EVT) cells?
EVT invade and remodel spiral arteries. This leads to more hypoxia and so more EVT; a positive feedback effect is observed.
Why do EVT cells invade and remodel spiral arteries?
To allow for optimum nutrient delivery for the baby.
Give 3 potential consequences of poor endovascular remodelling.
- Pre-eclampsia.
- IUGR.
- Pre-term birth.
Where should normal placenta invade into?
The decidua.
What is placental accreta?
When the placenta invades into the superficial myometrium.
What is placental increta?
When the placenta invades into the deeper myometrium.
What is placental percreta?
Invasion of the placenta into nearby organs e.g. the bladder.
What are the potential consequences, if left untreated, of a rhesus negative mother having a rhesus positive foetus?
There is a risk of RBC lysis -> foetal anaemia and death.
Describe the pathophysiology of rhesus disease.
- Foetal Rh+ RBC’s leak through the placenta and interact with the mother’s blood -> IgM reaction -> sensitisation.
- IgM can’t cross the placenta and so there is no RBC lysis but memory B cells are created.
- On a subsequent pregnancy, IgG may cross the placenta and cause foetal RBC lysis.
What is the only antibody that can cross the placenta?
IgG.
How can foetal RBC lysis be prevented in rhesus negative mothers?
Anti-D prophylaxis can be given. This destroys Rh+ IgG and so no RBC are attacked.
What is quiescence?
When the myometrium is inactive, there are no contractions.
Describe the physiology behind quiescence?
Increased cAMP -> K+ extrusion -> myocyte hyperpolarisation -> muscle fibres are unable to contract.
There is also phosphorylation of intracellular proteins -> actin-myosin ATPase is inactivated -> smooth muscle relaxation.
Give 2 theories behind the induction of labour.
- Placental clock theory.
2. Signals from the baby.
Induction of labour: describe the placental clock theory.
Increased release of CRH from the placenta -> foetal ACTH release -> release of oestrogens, formation of myometrial gap junctions -> regular and co-ordinated uterine contractions.
Induction of labour: describe the theory that suggests that there are signals from the baby.
Increased ACTH or increased foetal surfactant proteins activate amniotic fluid macrophages. These migrate to the uterine wall, there is up-regulation of inflammatory gene expression which stimulates labour.
Describe the 3 stages of parturition.
- Dilation - cervical remodelling and uterine contractions.
- Expulsion - full dilation to delivery of infant.
- Placental delivery.
Parturition: do progesterone levels fall when the cervix dilates and remodels?
Progesterone levels don’t fall but it becomes ineffective -> contractions.
Parturition: what happens in the expulsion phase that triggers myometrial contractions?
Oxytocin release -> increased intracellular Ca2+ -> myometrial contractions.
Why can nifedipine be used to inhibit premature contractions?
Nifedipine is a CCB and so can block the rise of intracellular calcium therefore inhibiting muscle contraction.
Name 2 drugs that can inhibit uterine contractions.
- Nifedipine - CCB.
2. Atosiban - oxytocin antagonist.
Name an oxytocin analogue that can indue labour.
Syntocinon.
Why is the incidence of breast cancer thought to be increasing?
- Western lifestyle.
- Screening.
- Increasing life expectancy.
What percentage of women who have a mammogram will be called back for more tests?
4/100 will need more tests.
1/4 of these women will then be found to have cancer.
Breast cancer: what is the triple assessment?
- Clinical examination e.g. palpation.
- Mammogram.
- Core needle biopsy.
Breast cancer: is a P1/2 lump that is described as soft, mobile and regular likely to be benign or malignant?
Benign. E.g. fibroadenoma.
Breast cancer: is a P4/5 lump that is described as hard, fixed and irregular likely to be benign or malignant?
Malignant.
Name 3 modifiable RF’s for breast cancer.
- Alcohol intake.
- Obesity.
- Use of HRT/OCP.
Name 3 non-modifiable RF’s for breast cancer.
- Age of menarche/menopause.
- Breast density.
- Genetics e.g. BRCA1/2.
Approximately what percentage of breast cancers are ductal and what percentage are lobular?
- Ductal (70%).
- Lobular (10%).
Give 4 signs that you may find on clinical examination that are suggestive of breast cancer.
- Palpable lump - irregular, hard, fixed, painless.
- Discharge from the nipple.
- Nipple in-drawing.
- Skin changes e.g. peau d’orange.
If a patient has breast implants or high density breasts a mammogram can be difficult to interpret. What investigation can be done as an alternative?
An MRI.
Give 3 treatment options for patients with breast cancer.
- Conservative surgery + radiotherapy.
- Mastectomy + radiotherapy.
- Mastectomy + reconstruction + radiotherapy (BUT can damage a lot of reconstructions).
- Axillary lymph node removal - limited removal or clearance.
Why might a mastectomy be indicated as opposed to a lumpectomy in someone with breast cancer?
- If the tumour is large relative to the size of breast.
- If there are multiple tumours.
- Patient preference.
What biopsy should you do to ensure that breast cancer hasn’t spread to the axillary lymph nodes?
A sentinel node biopsy.
Name 2 adjuvant treatments that can be given to women with oestrogen receptor + cancer.
- Tamoxifen (pre-menopausal).
2. Aromatase inhibitors (post-menopausal).
Why might a woman with breast cancer have chemotherapy?
If she has a very aggressive cancer or to shrink a tumour prior to surgery.
Give 3 non-pharmacological therapies that can be used to help manage labour pain.
- Trained support.
- Acupuncture.
- Hypnotherapy.
- Massage.
- Hydrotherapy.
Give 5 pharmacological therapies that can be used to help manage labour pain.
- Gas and air - entonox.
- Paracetamol.
- Codeine.
- Opioids e.g. pethidine, diamorphine.
- Epidural.
- Spinal anaesthesia.
Give 3 potential side effects of opioids.
- Sedation.
- Respiratory depression.
- Nausea and vomiting.
- They cross the placenta readily.
Where is spinal anaesthesia injected into?
The CSF.
Name an anaesthetic that can be given as an epidural.
Bupivacaine.
How does Bupivacaine work as an epidural?
It blocks sodium channels.
Give 3 indications for an epidural.
- Maternal request.
- Augmented labour.
- Twins.
- Existing co-morbidities.
Give 3 contraindications for an epidural.
- Maternal refusal.
- Local infection.
- Allergy.
Why would a general anaesthetic be given for performing a c-section?
If there is a threat to the mum or the foetus and so a regional anaesthetic is contraindicated.
Give 2 disadvantages of using a general anaesthetic for a c-section.
- Risk of aspiration.
2. Given IV and so the baby is anaesthetised too.
Give 3 advantages of using local anaesthetic when performing a c-section.
- Safer.
- You can see the baby immediately.
- Partner present.
Give 3 disadvantages of using local anaesthetic when performing a c-section.
- It can cause hypotension.
- It can cause headaches.
- The patient may experience discomfort from pressure sensations.
Define miscarriage.
The loss of a pregnancy before 24 weeks of gestation.
In approximately what percentage of pregnancies does miscarriage occur?
20%.
What is a threatened miscarriage?
When a lady experiences bleeding +/- pain but the cervical os is closed.
What is an inevitable miscarriage?
When a lady experiences heavy bleeding, clots, pain and the cervical os is open.
Define complete miscarriage.
When all the products of conception leave the body.
Define recurrent miscarriage.
> 3 consecutive miscarriages.
Give 4 potential causes of miscarriage.
- Abnormal foetal development.
- Uterine abnormality.
- Incompetent cervix.
- Placental failure.
- Multiple pregnancy.
Give 3 risk factors for miscarriage.
- Age >30.
- Smoking.
- Excessive alcohol consumption.
- Uterine surgery.
- Poorly controlled diabetes.
What investigations might you do to determine whether someone has had a miscarriage?
- Transvaginal USS.
2. Serum hCG.
Describe the management of a miscarriage.
- Vaginal misoprostol.
- Manual vacuum aspiration.
- Counselling and support.
What is a molar pregnancy?
A molar pregnancy is a type of GTD. It occurs when there is an abnormality in chromosomal number during fertilisation. A non-viable fertilised egg implants and fails to come to term. It grows into a mass in the uterus.
What is gestational trophoblastic disease (GTD)?
GTD describes a group of pregnancy related tumours. These tumours can be pre-malignant and often benign e.g. molar pregnancies or malignant e.g. choriocarcinoma and invasive mole.
Describe a partial molar pregnancy.
Where an ovum is fertilised by two sperm -> produces cells with 69 chromosomes (triploidy).
Describe a complete molar pregnancy.
Where one ovum without any chromosomes is fertilised by one sperm which duplicates. There are 46 chromosomes all of paternal origin.
Which type of molar pregnancy results in 46 chromosomes all of paternal origin?
A complete molar pregnancy.
Give 3 risk factor’s for GTD.
- Maternal age <16 or >45.
- Multiple pregnancy.
- Previous GTD.
- OCP.
Give 3 symptoms of molar pregnancies.
- Vaginal bleeding in early pregnancy.
- Abdominal pain in early pregnancy.
- Hyperemesis and hyperthyroidism in late pregnancy due to high levels of B-hCG.
What investigations might you do in someone to determine if they have GTD?
- Urine and blood B-hCG - will be very high.
2. USS - complete mole has ‘snow storm’ appearance.
What is the treatment for molar pregnancies?
Suction curettage.
Chemotherapy.
What is hyperemesis gravidarum?
Excessive vomiting, dehydration and ketosis in pregnancy.
With which placental hormone is hyperemesis gravidarum associated?
B-hCG.
How is hyperemesis gravidarum managed?
Rehydrate with IV fluids, vitamins and frequent small meals.
Give 2 methods used for monitoring the foetal heart rate.
- Intermittent auscultation using a pinard stethoscope or a hand held doppler.
- Continuous monitoring: cardiotocography (CTG).
FHR monitoring: give 2 advantages of intermittent auscultation.
- Cheap.
- Easy to do.
- Non invasive.
- Can be done at home.
FHR monitoring: give 2 disadvantages of intermittent auscultation.
- Variability is not detected.
- Long term monitoring is not possible.
- Quality of FHR can be affected by the maternal HR.
FHR monitoring: give 2 advantages of continuous monitoring.
- Gives lots of information e.g. variability, accelerations, decelerations etc.
- Continuous.
- Monitors FHR and uterine contractions.
FHR monitoring: give 2 disadvantages of continuous monitoring.
- Not very mobile - the mum’s abdomen is strapped.
2. Expensive.
CTG: what is a normal baseline HR?
110-160 bpm.
CTG: what is a non-reassuring baseline HR?
100-109 bpm.
CTG: what is an abnormal baseline HR?
<100 bpm.
>180 bpm.
CTG: what is normal variability?
> 5
CTG: what is non-reassuring variability?
<5 for 40-90 minutes.
Reduced variability could be due to foetal sleeping.
CTG: what is abnormal variability?
<5 for >90 minutes.
CTG: what is an acceleration?
An increase in the baseline HR by 10-15 bpm.
CTG: are accelerations reassuring or non-reassuring?
The presence of accelerations is reassuring.
CTG: are decelerations reassuring or non-reassuring?
Decelerations are non-reassuring.
CTG: what are early decelerations?
Early decelerations are seen just before a uterine contraction. They may be due to foetal head compression.
CTG: what are late decelerations?
Late decelerations are seen just after uterine contraction. They may be due to placental insufficiency and are often more sinister.
CTG: are early or late decelerations more concerning?
Late decelerations are more concerning.
CTG: what are variable decelerations?
When there is a mixture of early and late decelerations.
CTG: how would you determine if a CTG was overall normal, suspicious or abnormal?
- Normal: everything is normal and accelerations are present.
- Suspicious: one non-reassuring feature.
- Abnormal: >2 non-reassuring features and/or >1 abnormal feature.
How do you define a normal CTG? (BraVAD)
- Baseline HR - 110-160 bpm.
- Variability >5.
- Accelerations present.
- No decelerations.
What are the parameters used in determining whether a CTG is normal or abnormal?
- Baseline HR.
- Variability.
- Accelerations.
- Decelerations.
What is the gold standard method for direct FHR monitoring?
Scalp ECG.
Give a disadvantage of a scalp ECG for monitoring the FHR.
- Invasive.
- Membranes need to be broken and so cervix must be >2cm.
- Risk of scalp injury and infection risk.
What is the role of p53?
p53 is a tumour suppressor gene. It is a transcription factor that regulates cell division and death.
What is the role of Rb?
Rb is a tumour suppressor gene. It alters the activity of transcription factors and so controls cell division.
If there is a mutation in either p53 or Rb what might happen?
If a mutation occurs in these genes a patient may have uncontrolled cell growth -> cancer.
What are the roles of oncogenes?
Oncogenes stimulate excessive cell growth and cell division -> cancer development.
Give an example of an oncogene.
HER2.
What is the most common type of gynaecological cancer?
Endometrial cancer.
What is the pathophysiology behind endometrial cancer?
Unopposed oestrogen leads to endometrial hyperplasia and so an increased risk of endometrial adenocarcinoma.
Give 5 risk factors for developing endometrial cancer.
- Obesity.
- Diabetes.
- Nulliparity.
- Late menopause.
- HRT.
- Pelvic irradiation.
What is the most common type of endometrial cancer?
Endometrial adenocarcinoma.
What is the red flag symptom for endometrial cancer?
Post menopausal bleeding!
What investigations might you do if you suspect that a patient may have endometrial cancer?
- Pelvic and abdominal examination.
- Transvaginal USS.
- Endometrial biopsy.
- Hysteroscopy.
What type of staging is used for endometrial cancer?
FIGO staging.
Describe the treatment for endometrial cancer.
- Hysterectomy +/- pelvic lymph node removal.
2. Adjuvant radiotherapy and progesterone therapy.
Define adenocarcinoma.
A malignant tumour of glandular epithelium.
Why is the incidence of cervical cancer decreasing?
- Screening - cervical smears.
2. HPV vaccine.
Name 2 oncoproteins associated with HPV.
- E6 - blocks p53.
2. E7 - blocks Rb.
HPV: Which oncoprotein blocks p53?
E6.
HPV: Which oncoprotein blocks Rb?
E7.
Give 5 risk factors for HPV and so cervical cancer.
- Early age intercourse (<16).
- Multiple sexual partners.
- STI’s.
- Smoking.
- Multiparity.
- OCP.
What is the most common type of cervical cancer?
Squamous (90%).
What type of staging is used for cervical cancer?
FIGO staging.
What is the red flag symptom for cervical cancer?
Post-coital bleeding.
Describe the treatment for cervical cancer.
- <2cm - loop removal, just removing part of the uterus.
- > 2cm - radical hysterectomy.
- > 4cm - radiotherapy, chemotherapy, palliative care.
What must you consider when treating cervical cancer?
Fertility - is the patient likely to want children in the future?
Give 3 potential risks of performing a radical hysterectomy.
- Bowel problems.
- Sexual problems.
- Bladder problems.
- Lymphoedema.
Describe the aetiology of vulval cancer.
Vulval intraepithelial neoplasia (VIN - skin disease). Abnormal cells develop in the surface layers of the skin covering the vulva. It is not vulval cancer but may turn into cancer - pre-malignant. Usual type is associated with HPV infection.
What is the most common type of vulval cancer?
Squamous.
Give 5 symptoms of vulval cancer.
- Itching.
- Soreness.
- Lump.
- Bleeding.
- Pain on micturition.
Describe the treatment for vulval cancer.
- Surgery - radical or conservative.
- Radiotherapy.
- Chemotherapy.
Give 4 risk factors for developing ovarian cancer?
- Early menarche.
- Late menopause.
- Nulliparity.
- Genetics e.g. BRCA1/2.
Describe the epidemiology of ovarian cancer.
More common in women >50; post-menopausal. Often people present late and so it is advanced at presentation.
What are the commonest types of ovarian cancer?
- Epithelial (85%).
- Sex cord.
- Germ cell.
Give 5 symptoms of ovarian cancer.
- Bloating.
- Abdominal pain.
- Change in bowel habit.
- Urinary frequency.
- Bowel obstruction.
- Can often be asymptomatic.
What investigations might you do in a patient who you suspect has cervical cancer?
- Measure CA125.
- Trans-vaginal USS.
- Calculate the RMI (risk of malignancy index) - if this is >250 the patient should be referred under the 2 week wait system.
How is cervical cancer treated?
Surgery and chemotherapy should be offered.
Define incontinence.
The involuntary leakage of urine.
Incontinence: What is OAB?
Over-active bladder.
There are involuntary detrusor contractions -> urgency.
Give 3 symptoms of OAB.
- Urgency.
- Frequency.
- Nocturia.
- ‘Key in door’ urgency.
What is stress incontinence?
Stress incontinence occurs in patients with a week urethral sphincter. Anything that increases intra-abdominal pressure e.g. coughing, laughing, exercise results in the leakage of urine.
If a patient has a good bladder capacity and small volume leakage would this be more in keeping with a diagnosis of OAB or stress incontinence?
Stress incontinence.
What is the functional bladder capacity?
400ml.
Describe the epithelium of the detrusor muscle.
Smooth muscle with transitional epithelium.
Describe the innervation of the detrusor muscle.
Sacral parasympathetic innervation.
What investigations might you do in a patient complaining of incontinence?
- Bladder diary (frequency volume chart).
- Urinalysis.
- Residual urine measurement e.g. catheter or USS.
- ePAQ.
What information can you obtain from a bladder diary?
- Frequency.
- Quantity of urine.
- Fluid intake.
- Diurnal variation.
Investigating incontinence: what is ePAQ?
A questionnaire regarding urinary, bowel, vaginal and sexual symptoms.
Describe the non-pharmacological treatments for managing OAB.
- Lifestyle changes e.g. weight loss, stop smoking, reduce caffeine, avoid straining.
- Bladder drill.
- Pads.
Describe the non-pharmacological treatments for managing stress incontinence.
- Lifestyle changes e.g. weight loss, stop smoking, reduce caffeine, avoid straining.
- Physiotherapy e.g. pelvic floor exercises.
How do pelvic floor exercises work in treating someone with stress incontinence?
Pelvic floor muscle contraction -> urethra compression -> increased urethral pressure -> reduced leakage.
Vaginal cones can also be used.
What surgical options can be offered to patients with stress incontinence?
- Sling.
2. Suspension - restores pressure to the urethra and supports the urethra.
Name 3 drugs that can be used to treat OAB.
- Oxybutynin.
- Mirabegron.
- Botulinum Toxin.
How does oxybutynin work in treating OAB?
Oxybutynin is anticholinergic, it is an M2/3 receptor antagonist. It works by reducing detrusor muscle innervation and so its activity.
Give 3 potential side effects of oxybutynin.
- Dry mouth.
- Constipation.
- Blurred vision.
- Cognitive impairment.