Overview

• Spontaneous termination of a pregnancy. May either be early miscarriage (<12 weeks gestation) or late miscarriage (12-24 weeks gestation).

  • Missed Miscarriage → fetus is no longer alive, but no symptoms have occured. Fetus is dead (no foetal cardiac activity) but not expelled (present in uterus on USS).

  • Threatened Miscarriage → painless vaginal bleeding with a closed cervix and fetal heartbeat present. (25% chance of actual miscarriage)

  • Invevitable Miscarriage → heavy bleeding with clots and pain with an open cervix.

  • Incomplete Miscarriage → retained products of conception remain in the uterus after the miscarriage. May have passage of some products of conception.

    <aside> 💡 Open your ‘I’s → cervical os open in inevitable and incomplete miscarriage.

    </aside>

  • Complete Miscarriage → expulsion of the entire fetus through the cervix. US will show empty uterus.

  • Recurrent Miscarriage → ≥3 consecutive miscarriages.

• 15-20% of diagnosed pregnancies will miscarry in early pregnancies.
  • Number of Miscarriages (% chance of livebirth in subsequent pregnancy) → 1 (85%), 2 (75%), 3 (60%).
• Causes of Miscarriage → chromosomal abnormalities, fetal malformations, infection, antiphospholipid syndrome, endocrine disorders (PCOS, poorly controlled diabetes), smoking, uterine or cervical problems, age (>35), weight (over/under), invasive prenatal tests.
  • Recurrent Miscarriage (≥3 consecutive) → antiphospholipid syndrome, endocrine disorders (poorly controlled diabetes, PCOS), uterine abnormality (uterine septum), parental chromosomal abnormalities, smoking.
    • Early Miscarriages (<10 weeks) are most commonly caused by genetic or chromosomal abnormalities.
  • Investigations (after ≥3 consecutive) → cytogenic analysis of products of conception, pelvic USS (structural abnormalities), anti-phospholipid antibodies, anticardiolipin antibodies, screen for BV. Often the cause is never found.
  • Antiphospholipid Syndrome → typically occur after first trimester. Will also have evidence of recurrent thrombosis. Ix → anticardiolipin antibodies. Mx → low-dose aspirin and LMWH.

Making Diagnosis

Clinical Features

• PV bleeding, cramping abdominal pain, fever.

Investigations

• Main Investigation → transvaginal ultrasound scan (TVUSS).
  • Key Features to look for in Early Pregnancy → mean gestational sac (GS) diameter, fetal pole and crown-rump length (CRL), fetal heartbeat (FH).
  • TVUSS Process (1st: look for FH → 2nd: look for CRL → 3rd: look for GS) ⇒
    • No FH + CRL >7mm → miscarriage. Repeat scan after 1 week to confirm / 2nd opinion.
    • No FH + CRL <7mm → TVUSS in 7-10 days.
    • GS >25mm + no fetal pole → miscarriage. Repeat scan after 1 week to confirm / 2nd opinion.
    • GS <25mm + no fetal pole → TVUSS in 7-10 days.

Management Plan

• ABCDE Assessment.
• Threatened Miscarriage → return for further assessment if bleeding gets worse or persists beyond 14 days. Continue routine antenatal care if bleeding stops.
• <6 Weeks Gestation → expectant management. If pain or risk factors for ectopic, need admission.
  • Pregnant women who are <6 weeks gestation and present with vaginal bleeding and no pain can be managed expectantly (no need to go to EPAU for TVUSS). No USS, just send home. Advise to repeat urine pregnancy test after 7-10 days and return if test is positive.
• >6 Weeks Gestation → referral to an early pregnancy assessment service (EPAU).
• 3 options for managing miscarriage ⇒
  1. Expectant Management → first-line for women without risk factors for heavy bleeding or infection. 7-14 days (REVIEW AT 14 DAYS) given for miscarriage to occur spontaneously. Repeat urine pregnancy test 3 weeks after bleeding. Advise to expect heavier bleeding with clots + offer analgesia.
     • Indications to go straight to Medical/Surgical → increased risk of haemorrhage (in late first trimester or she has coagulopathies), previous adverse pregnancy experience (stillbirth, miscarriage, antepartum haemorrhage), evidence of infection (fever).
  2. Medical Management → PV misoprostol (prostaglandin analogue) softens cervix and stimulates uterine contractions. This will expedite the miscarriage. Repeat urine pregnancy test after 3 weeks. Sfx include heavier bleeding, pain, nausea/vomiting and diarrhoea. Also give analgesics and anti-emetics. If bleeding not started within 24 hours, contact doctor.
  3. Surgical Management → manual vacuum aspiration under local anaesthetic to aspirate the contents of the uterus. Electric vacuum aspiration (aka ERPC) under general anaesthetic. Anti-D prophylaxis to all rhesus-negative women undergoing surgical management of miscarriage.
     1. Risks of Surgery → bleeding, infection, damage to surrounding structures, VTE risk.
• Incomplete Miscarriage → medical management involves misoprostol. Surgical management involves evacuation of retained products of conception (ERPC). Cervix is widened and retained products are manually removed using vacuum aspiration and curettage (key complication is endometritis).
  • Missed Miscarriage → oral mifepristone + misoprostol 48 hrs later.