Miscarriage, Ectopic Flashcards
What is the definition of a miscarriage?
● Spontaneous loss of pregnancy before 24 weeks of gestation (NICE CKS).
What is the pathophysiology and aetiology of miscarriage?
Pathophysiology and Aetiology:
● Chromosomal abnormality (commonest) - typically autosomal trisomies.
○ Can result in failure of development of embryo within gestational sac.
● Hormonal factors:
○ PCOS, hyperprolactinaemia, diabetes, hyper/hypothyroidism
● Thrombophilia / autoimmunity:
○ Antiphospholipid syndrome, factor V Leiden - induces placental thromboses
leading to placental insufficiency.
● Anatomical factors:
○ Bicornuate uterus, cervical insufficiency
● Infection:
○ Toxoplasmosis, syphilis
What are the risk factors for a miscarriage?
● Increased maternal age
● Previous miscarriage
What are the different types of miscarriage?
● Threatened: vaginal bleeding in the first 24 weeks of pregnancy (with viable intrauterine
pregnancy).
● Incomplete: non-viable pregnancy, bleeding begun, products of conception in uterus.
● Complete: all products of conception passed, bleeding has stopped.
● Missed: non-viable pregnancy on ultrasound (without pain / bleeding).
○ Mean gestational sac diameter >25mm with no yolk sac or
○ CRL >7mm with no cardiac activity
● Inevitable: non-viable pregnancy, bleeding begun, cervical os opened, POCs remain in
uterus.
How can a miscarriage present?
● Pelvic pain
● Vaginal bleeding
What are some differentials for for a miscarriage?
gestational
trophoblastic disease, implantation bleeding, ectopic pregnancy, and importantly,
bleeding without an identified cause.
What is first line investigation for a miscarriage?
○ Transvaginal ultrasound scan - to identify location, foetal pole and heartbeat.
How do we manage a threatened miscarriage?
○ Manage conservatively: if no history of previous miscarriage, advise to return if
bleeding persists after 14 days / becomes heavier. If there is a history of previous
miscarriage, offer vaginal progesterone until 16 weeks of pregnancy completed.
○ Advise to take a pregnancy test 3 weeks after bleeding has stopped.
○ If bleeding is ongoing, offer a repeat scan.
How do we manage and incomplete/inevitable miscarriage?
○ First Line - expectant management (appropriate to 13 weeks gestation):
■ Allow 7-14 days for POCs to pass / bleeding to end.
○ Second Line - medical management:
■ mifepristone, followed by misoprostol 48 hours later.
○ Alternative Second Line - surgical management:
■ Vacuum aspiration under local or dilatation and evacuation under GA
○ Plus: pregnancy test 3 weeks post-miscarriage
How do we manage a missed miscarriage?
○ As above, but use misoprostol only for medical management.
What are some contraindications to expectant management?
- Heavy vaginal bleeding / increased risk of bleeding / increased vulnerability to heavy bleeding
(coagulopathy) - Previous traumatic experience in pregnancy
- Evidence of infection
What is the mechanism of mifepristone?
- Antiprogesterone; sensitises myometrium to prostaglandins, induces breakdown of decidua basalis
What is the mechanism of misoprostol?
- Prostaglandin E1 analogue; degrades cervical collagen, stimulates uterine contraction
According to the 1967 Abortion act which four legal grounds give acceptance for a termination of pregnancy?
- Pregnancy before 24 weeks - continuation risks injury to physical / mental health of the
pregnant woman / her children. - Necessary to prevent grave permanent injury to physical / mental health of the pregnant
woman. - Continuation of pregnancy involves risk to the life of the pregnant woman.
- Substantial risk of serious physical / mental disability to the child if it were born.
What is the medical way of abortion?
○ Up to 9+6 weeks - single dose mifepristone, followed by single dose PO / PV
misoprostol 48 hours later
○ 10+0 to 23+6 weeks - single dose mifepristone, followed by serial misoprostol
every 3 hours.
○ Analgesia - NSAIDs, opioids as required.
What is the surgical way of abortion?
○ Up to 13+6 weeks - cervical priming with misoprostol or mifepristone, followed by
vacuum aspiration.
○ 14+0 to 24+0 weeks - cervical priming with mifepristone + misoprostol or osmotic
dilator, followed by dilatation and evacuation.
○ Plus - oral doxycycline to prevent infection.
○ Analgesia - NSAIDs, local anaesthetic, conscious sedation.
Summary of medical and surgical abortion
○ Medical - mifepristone plus misoprostol taken 48 hours later
○ Surgical - misoprostol plus vacuum aspiration / dilatation and evacuation.
Because abortion is a sensitising event, what should be offered?
Anti-D should be offered after 10+0 weeks to women
who are Rhesus negative.
What is the definition of an ectopic pregnancy?
● Any pregnancy that implants outside of the endometrial cavity. 97% are implanted in a
fallopian tube.
Pathophysiology and aetiology of ectopic pregnancy?
● Fertilisation of the oocyte typically takes place in the ampulla of the fallopian tube; the
conceptus must then travel into the endometrial cavity.
○ This occurs due to tubal peristalsis alongside ciliary motion and tubal fluid flow.
○ Any dysfunction in the above due to e.g. tubal surgery, salpingitis, PID can
prevent the conceptus from implanting in the correct place.
● A pregnancy that implants in the fallopian tube will grow and eventually lead to rupture
and catastrophic bleeding.
● Most tubal ectopics implant in the ampulla (widest point).
What are the risk factors for an ectopic pregnancy?
- Previous ectopic pregnancy
- Cu-IUD use (although background risk of pregnancy is obviously much lower).
- Chronic salpingitis (tubal inflammation)
- PID
What is the presentation of ectopic pregnancy?
● Typically presents at 6-8 weeks after LMP; at this point the conceptus has grown to
sufficient size to cause symptoms / signs.
What are the signs of an ectopic pregnancy?
lower abdominal tenderness / adnexal tenderness, cervical motion tenderness.
What are the symptoms of an ectopic pregnancy?
lower abdominal pain, amenorrhea, PV bleeding, urge to defecate, shoulder
pain.