Placental problems Flashcards
Define what early and late antepartum, intrapartum and postparum stages of pregnancy are
Antepartum:
* Early: less than 24 weeks
* Late: more than 24 weeks
Intrapartum
In labour- first and second stages
Postpartum
From delivery of the fetus until 6 weeks later
What is the name for severe morning sickness? [1]
Hyperemesis Gravidarum
Explain the pathophysiology behind Hyperemesis Gravidarum
When does it peak? [1]
Correlates closely with hCG levels: which is what controls placental development.
hCG may stimulate oestrogen production from ovary causing vomiting and nausea
May be caused by vitamin B6 (Pyridoxine) deficiency (vit. B supplements cause reduction in symptoms)
Peaks at about 12 weeks
Define what a spontaneous miscarriage is [1]
Fetus dies or is delivered dead before 24 weeks (most occur before week 16)
What are the 8 types of spontaneous miscarriage [8]
State in each if there is vaginal bleeding or not [8]
Complete: vaginal bleeding, both placenta and embryo expelled
Incomplete: vaginal bleeding, embryo commonly lost, placenta retained
Threatened: vaginal bleeding, fetal activity (can be potentially saved)
Missed: embryo and placenta is still in uterus, but embryo is dead. no vaginal bleeding
Recurrent: history of more than 3 spontaneous abortions
Inevitable: vaginal bleeding embryo and placenta are on the way out / coming
Septic (Rare often results from non sterile use pelvic instrumentation)
Therapeutic
State in each type if the cervix is opened or closed
What are the products of conception [2]
embryo and placenta
Which causative agents commonly cause a septic miscarriage? [3]
Explain why a septic miscarriage occurs [1]
What are causes of septic miscarriage? [2]
Usually due to Staph aureus
N. gonorrhea, C. trachomatis
Causes the contents of the uterus to be infected & causes endometritis (so may present with signs of pelvic infection)
Causes:
* Unsafe abortion
* Cervical incompetence
What are symtpoms of septic miscarriage:
- localised [3]
- systemic [2]
Localised:
* tender uterus
* purulent cervical discharge
* signs of pelvic infection
Systemic:
* fever
* chills
How do you investigate for a spontaneous miscarriage? [3]
- Ultrasound scan: ID if placenta is attached to the uterus
- Serum BetaHCG indicates that placenta is there (doubles every two-three days) - if placenta not attached to uterus the hCG levels will not rise
- Rhesus status
Management of miscarriage?
- medical [1]
- surgical [1]
- for rhesus negative women [1]
Medical:
* misoprostol - cause the uterus to contract to expel the products of conception that are still there
Surgical:
* Surgical aspiration - gentle suction to remove the pregnancy
* Curettage (spoon-shaped instrument) to remove abnormal tissues.
Anti D to rhesus negative women
Recurrent miscarriage:
How many consecutive miscarriages needed to be classified? [1]
What investigations would you use for recurrent miscarriage? [3]
3 or more consecutive miscarriages before week 20
Investigations:
* Autoimmune + thrombophilia screen
* Karyotyping
* Pelvic US scan
How should a cervix appear during normal pregnancy? [1]
How does it appear during cervical incompetence? [1] What are the consequences? [2]
Cervix should be closed
Cervical incompetence: cervix is open: causes amniotic sac to come down through the cervix. Risk of miscarriage or infection
When i s
How do you ID cervical incompetence
Funnel shaped cervix on ultrasound
How do you manage cervical incompetence? [1]
Transvaginal cerclage: Ring of stiches around cervix
(In a transvaginal cerclage (TVC), doctors sew the cervix closed, usually during the 13th or 14th week of pregnancy. At 36 weeks, the stitches are taken out so the woman can deliver her child naturally)
Define ectopic pregnancy [1]
Implantation of the fertilised ovum outside of the endometrial cavity
What are risk factors for ectopic pregnancy?
Risk factors
STIs/PID
Emergency contraception
IVF
Pelvic surgery
Smoking
IUCD in situ
Failed sterilisation
Previous ectopic
How would person with ectopic pregnancy present?
- Women of reproductive age
- Positive pregnancy test/ Amenorrhoea 4-10 weeks
- PV bleeding
- Low abdominal pain - in right or left iliac fossa
- Collapse +/- shoulder tip pain
- Beta hCG is lower that normal (because no placenta in the uterus)
- No products of conception in the uterus
How does beta hCG change during pregnancy? (when does it peak)
Typically, the hCG levels will double every 72 hours. The level will reach its peak in the first 8-11 weeks of pregnancy and then will decline and level off for the remainder of the pregnancy.
Define Gestational trophoblastic disease (GTD)
What is a partial mole? [1]
What is a monospermic complete mole? [1]
What is a dispermic complete mole? [1]
GTD: When the trophoblastic tissue that forms part of the blastocyst proliferates more aggressively than normal
Partial mole: two sperm fertilse an egg creating 69 chromosome
Monospermic mole: maternal chromosomes are lost AND paternal chromosomes double up to make 46 chromosome
Dispermic complete mole: maternal chromosomes are lost AND fertilisation by two sperm: 46 chromosome
Explain pathophysiology of complete molar pregnancy: GTD
How do you treat? [2]
Complete molar pregnancy: entirely paternal tissue
No fetal tissue at histology - just placenta.
Effectively a tumour:
* surgical removal - but 15% molar tissue remains in deeper tissues of the womb so:
* need chemotherapy to remove abnormal cells
Is the placenta derived from mother or father genetically? [1]
Father
Explain what a partial molar pregnancy is [1]
Explain how a partial molar pregnancy occurs [1]
How do you treat? [1]
Happens when two sperm fertilise the egg at the same time- one set of chromosomes from the mother and two sets from the father: 69 chromosomes
Some fetal tissue might be seen within the molar tissue
Treatment:
Surgery to remove molar tissue - 1% have some remaining abnormal cells which require chemotherapy
Explain what placental abruption is and the pathophysiology behind it
How serious is a placental abruption? [1]
Blood accumulates behind the placenta: causes uterus to be hard / wood & the placenta comes away from uterine wall
Obstetric emergency!
How is placental abruption treated?
If the baby is dead? [1]
If no fetal or maternal distress? [1]
Deliver baby
Fetal distress: Urgent lower segment caesarean section
If the baby is dead: Coagulopathy likely, Induce labour when safe
If no fetal or maternal distress:
Steroids and observe
Define placenta praevia [1]
What are the two types [2]
When placenta is inserted into lower segment of the uterus after 24 weeks
Major = covers cervix and internal os
Minor = marginal <2cm from internal os
What are the symptoms of placenta praevia? [2]
How is placenta praevia detected? [1]
Uterus soft and non tender
Painless vaginal bleeding (usually between 32-37 weeks)
Detected by US
The main complication of placenta praevia is haemorrhage before, during and after delivery.
Define what placenta Accreta/increta/percreta are [3]
How do you treat if maternal / fetal compromise at more than 37 weeks? [3]
Accreta –chorionic villi attach to myometrium rather than restricted within decidua basalis. Most common
Increta – chorionic villi invade myometrium
Percreta – chorionic villi invade through perimetrium
Treatment:
* Emergency Caesarean plus hysterectomy
* Methotrexate
* Close pelvic vessels
Define pre-eclampsia [1]
HTN that develops during pregnancy after 24 weeks
Describe pathophysiology of pre-eclampsia
What are effects of pre-eclampsia? [2]
Normal spiral artery in placenta should widen – slows blood flow so nutrient exchange can occur
Pre-eclampsia this doesn’t happen. Spiral arteries stay narrow: goes in at high pressure.
This causes oxidative stress in the placenta, and the release of inflammatory chemicals into the systemic circulation, leading to systemic inflammation and impaired endothelial function in the blood vessels.
Causes: fetal growth restriction or pre-term birth
Which syndrome may pre-eclampsia lead to? [1]
What are the symptoms of this syndrome? [3]
Woman with this condition may develop the HELLP syndrome
This is characterised by haemolysis (raised LDH), elevated liver enzymes and low platelets.
Which condition can pre-eclampsia lead to? [1]
How can you prevent progession to this ^? [1]
What is the only definitive treatment for pre-eclampsia? [1]
A complication of pre-eclampsia includes progression to eclampsia, which should be prevented by administration of magnesium sulphate.
The only definitive treatment for pre-eclampsia is delivery
Management of pre-eclampsia:
What BP should you aim for? [1]
What drugs do you use to stabilise mothers BP? [2]
Which anti-hypertensives & anticonvulsants would you use for acute [2] and chronic treatment? [2]
- BP aim: less than 135 / 85 mmHG
- Stabilise mothers BP: aspirin (from week 12 to birth); calcium supplementation (from week 20 onwards)
- Acute treatment:
Labetalol – alpha and beta blocker / antagonist
Hydralazine - Chronic management
Methyldopa – alpha 2 agonist (feeds back and stops noradrenaline being released)
Nifedipine - CCB
Explain the pathophysiology behind Hyperemesis Gravidarum [4]
When does it peak? [1]
Correlates closely with high hCG levels: which is what controls placental development
From placenta: get higher levels of GDF15
hCG may stimulate oestrogen and progesterone production from ovary causing vomiting and nausea
May be caused by vitamin B6 (Pyridoxine) deficiency (vit. B supplements cause reduction in symptoms)
Peaks at about 12 weeks
Name and explain the MoA of the anti-emetics you would use to treat hyperemesis gravidarum [4]
- Prochlorperazine (stemetil)
- Cyclizine: histamine H1 receptor antagonist
- Ondansetron: Blocks 5HT-3 in chemical trigger zone/vomiting centre
- Metoclopramide: Blocks D2 in chemical trigger zone/vomiting centre
- Vitamin B6
Why might hyperemesis gravidarum cause hosptialisation? [4]
- Dehydration
- Electrolyte imbalance
- ketosis
- weight loss
Name 5 reasons for bleeding in early pregnancy [5]
What is prognosis for bleeding in early pregnancy? [2]
- Cervical insensitivity
- Infection
- Molar pregnancy
- Subchorionic haemorrhage
- Implantation bleeding
50% will settle
50% will:
Miscarry (spontaneous abortion)
Have an ectopic pregnancy
Have trophoblastic disease (hydatidiform mole)
Have problems in late pregnancy
What is twin to twin transfusion? [1]
Which type of pregnancy does it occur in? [1]
How do you treat? [1]
which twins share unequal amounts of the placenta’s blood supply resulting in the two fetuses growing at different rates.
Only affects mono-chorionic pregnancies
Treat with laser ablation on the anastomosing vessels
What is velamentous insertion of umbilical cord into placenta?
complication that happens when the umbilical cord from a fetus doesn’t insert into the placenta correctly.
causes compression of own bloody supply
If a women has endometriosis and pain when defecating, where are the locations that might get likely accumulation of blood from the extra-pelvic endometrial tissue? [2]
Pouch of Douglas
Bowel
