Bleeding in pregnancy Flashcards
Placental abruption : Risk factors
Factors which cause vasocontriction of the uterine arteries such as;
1. * Smoking
1. * Chronic hypertension
1. * Cocaine and methamphetamine use
1. * Multiparity and increased maternal age
1. * Trauma
Placental abruption : Pathophysiology
- Seperation of the placenta from the surface of the uterus leading to bleeding into the myometrium
- Caused by degemeration of the uterine arteries which supply blood to the placenta
- Diseases vessels rupture, causing haemorrhaging and seperationg of the placenta
Placental abruption : Clinical features
- Abdominal pain
- Mild to severe vaginal bleeding } may not be in proportion to blood loss and blood may accumulate within the myometrium surface
Placental abruption : Clinical signs
- Tense uterus : Myometrium contracts to reduce bleeding
- Fetal bradycardia } intrauterine hypoxia due to loss of placenta
Placental abruption : complications
- DIC : may lead to excessive vaginal bleeding
- Hypovolaemic shock
- Sheehan’s syndrome : pituitary necorsis
- Premature birth
Placental abruption : Investigation
- Ultrasound : show retroplacental blood collection
- Foetal HR : Deceleration of foetal heart beat
Placental abruption : Management
Indication :
Severe haemorrhaging or foetal compromise : Urgent C-section
Placenta previa : Definition
Implantation of the placenta in the lower segment of the uterus - close to or covering the cervical os
Placenta previa : Pathophysiology
- Implantation near or over the cervical os
- Uterine segment grow
- Distruption of the uterine blood vessels
- Resulting in ; Vaginal bleeding
Placenta previa : Classification
⦁ I - placenta reaches lower segment but not the internal os
⦁ II - placenta reaches internal os but doesn’t cover it
⦁ III - placenta covers the internal os before dilation but not when dilated
⦁ IV (‘major’) - placenta completely covers the internal os
Placenta previa : Causes
- Placenta inplants in the lower uterus due to endometrium in the upper uterus not being well vascularised
- Secondary to previous endometrial damage
Placenta previa : Risk factors
- Multiple gestations ie. multiple placenta
- Previous C section/Uterine surgery } likely to implant on a lower segment scar from previous C section
- Multiparity
- Intrauterine fibroids
- Materanal age >.35
- Smoking
Placenta previa : Clinical features
- Vaginal bleeding } in proportional to blood loss/haemodynamic stability
- Pain free - bleeding frm placenta, not the uterus
Placenta previa : Clinical signs
- Non tender uterus
- Avoid Bimanual exam before US } may provoke haemorrhage
Placenta previa : Diagnosis
Transvaginal ultrasound } picked up at 20 weeks routine abdominal US
Placenta previa : Mangement with vaginal bleeding
⦁ Admit
⦁ ABC approach to stabilise the woman
⦁ if not able to stabilise → emergency caesarean section
⦁ if in labour or term reached → emergency caesarean section
Placenta previa : Mangement w/o bleeding
i. If low-lying placenta at the 20-week scan:
ii. rescan at 32 weeks
iii. if still present at 32 weeks
- Grade I/II -> scan every 2 weeks
I. final ultrasound at 36-37 weeks to determine the method of delivery - Grade I : then a trial of vaginal delivery may be offered
- Grades III/IV : elective caesarean section between 37-38 weeks
Placenta previa : Main complication
Post partum Haemorrhage
Placenta accreta : Definition
- Attachment of the placenta to the myometrium, due to a defective decidua basalis
- Chorionic villi attatch to the myometrium
Placenta accreta : Pathophysiology
- Adherence of chorinionic villi directly to the myometrium
- Placenta fails to fully seperate after foetum is delivered
- Partial/incomplete seperation } induces post partum haemorrhaging
Placenta accreta : Clinical signs and symptoms
- Placenta fails to spontaneiously deliver after foetal birth
- Manual seperation } increases bleeding
- ‘Boggy/Soft’ uterus unresponsive to uterine massage } 2nd to Myometrium haemorrhaging
Placenta accreta : Risk factors
i. Previous caesarean section
ii. Placenta praevia
Placenta accreta : Complication
Post partum haemorrhage
Post partum haemorrhage : Definition
Excessive blood loss after giving birth
* > 500ml after vaginal delivery
* >100ml after Caesarean delivery
Post partum haemorrhage : Types
> Primary : within 24 hours after delivery
Secondary : >24 hours but <6 weeks post partum
Post partum haemorrhage : Causes
-
Tone : Uterine atony } Most common cause
ineffective uterine contraction to clamp and stop arterial bloodless
* Causes : Excessive myometrium stretching (Multiple gestation
-Polyhydramnios) or fatigue in prolonged labour or full bladder (can interfere with contractions) -
Trauma: damage to reproductive structure
* Causes : incision, uterine rupture, large foetus -
Tissue: retained placental fragments
* Causes : Placenta accrete - Thrombin : impaired clotting
Post partum haemorrhage : Secondary haemorrhage causes
Retained placental tissue or endometritis
Post partum haemorrhage : Risk factors
- Previous PPH
- Prolonged labour
- Pre eclampsia
- Increased maternal age
Post partum haemorrhage : Management - Mechanical
- Palpate fundus and rub to stimulate contraction
Post partum haemorrhage : Management - Medical
- IV Oxytocin: Stimulates uterine contraction
-
IV Ergometrine: Vasoconstriction and stimulates uterine contraction
-Avoid in hypertension -
IV Carboprost : Stimulate uterine contraction
-Prostaglandin analogue : can cause bronchoconstriction
-Avoid in asthma - Misprostol sublingual: prostaglandin analogue
Post partum haemorrhage : Management - Surgical
First line : Intrauterine Balloon tamponade
Gestational trophoblastic disease : Definition
Describes a spectrum of disorders originating from the placental trophoblast:
* complete hydatidiform mole
* partial hydatidiform mole
* choriocarcinoma
Complete hydatiform mole : Definition
- Benign trophoblastic tumor
- Empty egg is fertilized by a single sperm that then duplicates its own DNA
- Egg : 46 chromosomes of paternal origin
Partial hydatiform mole : Definition
a normal haploid egg may be fertilized by two sperms, or
by one sperm with duplication of the paternal chromosomes
Usually triploid - e.g. 69 XXX or 69 XXY. Fetal parts may be seen
Gestational trophoblastic disease : Clinical feature
- bleeding in first or early second trimester
- exaggerated symptoms of pregnancy e.g. hyperemesis
- uterus large for dates
- very high serum levels of human chorionic gonadotropin (hCG)
- hypertension and hyperthyroidism* may be seen
Gestational trophoblastic disease : Management
- urgent referral to specialist centre - evacuation of the uterus is performed
- effective contraception is recommended to avoid pregnancy in the next 12 months
