Placental Problems in Pregnancy Flashcards
Define placentation
the formation or arrangement of a placenta or placentae in a woman’s uterus.
What is hyperemesis gravidarum?
Severe nausea and vomiting which can cause electrolyte imbalance, weight loss and hospital admission
What is the mechanism behind hyperemesis gravidarum?
bHCG may stimulate upper GI tract (as it’s structurally similar to TSH so can affect its receptors)
How is hyperemesis gravidarum treated?
Thaimine, diet, IV fluids(no dextrose) and antiemetics
How many pregnancies miscarry?
20-30%
What are the different forms of miscarriage?
Threatened, inevitable, incomplete, complete, septic and missed
What is a threatened miscarriage?
There is light and painless bleeding from the vagina, but the foetus is still alive. The cervical os is closed.
25% will go on to miscarry
What is an inevitable miscarriage?
Bleeding is normally heavier and the foetus may be alive at this point, but the cervical os is open, and this is associated with pelvic cramps and is indicative that miscarriage is about to occur
What is an incomplete miscarriage?
Where only some of the foetal parts have been passed. The cervical os is open and the vaginal bleeding continues
What is a complete miscarriage?
All foetal tissues have been passed and the bleeding has diminished/stopped but the uterus is no longer enlarged and the os is CLOSED
What is a septic miscarriage?
Contents of the uterus become infected and this causes endometritis where there is a tender uterus, fever may not be present and this condition may progress to a pelvic infection that causes abdominal pain and peritonism
What is a missed miscarriage?
The foetus has not developed or has died in utero, and this is only recognised later when the bleeding occurs or on an USS (ultrasound scan). The uterus is smaller than would be expected for the dates. The cervical os is closed and the abdominal pain and vaginal bleeding are minimal.
How are miscarriages managed?
Expected - wait and use syncytocinon or ergometrine if blood loss is large.
Foetal tissue may be removed using prostaglandins e.g. misoprostal
What is recurrent miscarriage?
Three or more consecutive miscarriages
What is the cause of recurrent miscarriages?
Autoimmune disease, chromosomal defects in the couple, hormonal factors, anatomical factors (cervical incompetence) or infection
What is a molar pregnancy?
Also known as gestational trophoblastic disease. This is an abnormal pregnancy where a non-viable fertilised egg implants in the uterus and will fail to come to term
Explain the pathophysiology of molar pregnancies
Trophoblastic tissue grows into a mass in the uterus with swollen chorionic villi. These villi then grow in clusters which resemble grapes
How does a molar pregnancy arise?
Involves unviable fertilised eggs growing.
A complete mole involves two sets of paternal genes and no maternal genes which produces no foetus.
A partial mole involves 2 sets of paternal gene and 1 set of maternal which forms a non-viable foetus
What are the symptoms of a molar pregnancy?
Light, torrential vaginal bleeding, hyperemesis gravidarum (due to excess hCG production) and passage of vesicles from vagina
How does a molar pregnancy appear on ultrasound?
Has a snowstorm appearance
What are the common causes of bleeding in late pregnancy (antepartum haemorrhage)?
Placental abruption or praevia
What is placental abruption?
Painful vaginal bleeding from a normally-sited placenta
What are the risk factors for placental abruption?
Multiparity, trauma, smoking
What are the clinical signs of placental abruption?
Intense, constant abdominal pain (with or without vaginal bleeding, profound shock (DIC and oliguria), a tense and tender ‘woody’ uterus.
Foetal heart may be weak or absent
What is the treatment for placental abruption?
If there is foetal distress before 37 weeks –> emergency C-section. If after 37 weeks labour, and no foetal distress, should be induced
What is placenta praevia?
Where the placenta is inserted into the lower segment of the uterus after 24 weeks
What is major placenta praevia?
Where the placenta covers the cervical os
What is minor placenta praevia?
Where the placenta doesn’t cover the cervical os
What is the clinical presentation of placenta praevia?
Painless vagina bleeding with soft and non-tender uterus
Wha are the potential complications of placenta praevia?
Requirement for C-section due to canal obstruction, postpartum haemorrhage (as lower segment of uterus is less able to contract), placenta accrete (placenta implants in previous C-section scar –> may need hysterectomy)
What is pre-eclampsia?
Abnormal maternal adaptation to the trophoblast leading to systemic hypertension
How do you diagnose pre-eclampsia?
Protein in the urine and hypertension
What are the signs of pre-eclampsia?
Hypertension, renal impairment, proteinuria, fluid retention, edema, weight gain and diffuse inseminated coagulopathy
How is pre-eclampsia managed?
Monitoring and anti-hypertensives and anticonvulsants
Describe twin to twin transfusions (TTTS) as a complication of multiple pregnancy
Occurs in monochorionic pregnancies where the one twin may take all of the nutrition
