Armando Hasudungan
Biology and Medicine videos

Miscarriage

Overview

Definition
Miscarriage:
 Spontaneous abortion, or miscarriage, is defined as a clinically recognized pregnancy loss before the 20th week of gestation. Others define it as expulsion or extraction of an embryo or fetus weighing 500 g or less
Abortion: After 20weeks
Threatened miscarriage: A pregnancy less than 20 weeks’ gestation associated with vaginal bleeding, generally without cervical dilation.
Inevitable miscarriage: A pregnancy less than 20 weeks’ gestation associated with cramping, bleeding, and cervical dilation; there is no passage of tissue.
Incomplete miscarriage: A pregnancy less than 20 weeks’ gestation associated with cramping, vaginal bleeding, an open cervical os, and some passage of tissue per vagina, but also some retained tissue in utero. The cervix remains open due to the continued uterine contractions; the uterus continues to contract in an effort to expel the retained tissue.
Completed miscarriage: A pregnancy less than 20 weeks’ gestation in which all the products of conception have passed; the cervix is generally closed. Because all the tissue has passed, the uterus no longer contracts, and the cervix closes.
Missed miscarriage: A pregnancy less than 20 weeks’ gestation with embryonic or fetal demise but no symptoms such as bleeding or cramping.
Ectopic Pregnancy: Pregnancy outside of the normal uterine implantation site. Most of the time, this means a pregnancy in the fallopian tube.
Human Chorionic Gonadotropin: “The pregnancy hormone,” which is a glycoprotein that is secreted by the chorionic villi of a pregnancy. It is the hormone on which pregnancy tests are based. The normal pregnancy will have a logarithmic rise in early pregnancy. Usually the β-subunit is assayed to prevent cross-reactivity with LH.

Classification - Overview

Terminology History Substance Cervical Os Viability Treatment
Threatened Vaginal bleeding No Closed Uncertain Transvaginal ultrasound and hCG levels
Inevitable Cramping, bleeding No Open Abortion is inevitable D&C vs expectant management
Incomplete Cramping, bleeding Some but not all tissues passed Open Nonviable D&C
Complete Cramping bleeding All tissues passes Closed Nonviable Follow hCG levels to negative
Missed/delayed No symptoms No Closed Nonviable D&C vs expectant management

Risk Factors

 

  • Previous miscarriage
    • Three consecutive miscarriages (classified as recurrent and requires investigation)
  • Maternal age 35+ (20%)
  • Maternal age 40yo (>40%)
  • Maternal age 45yo (>80%)
  • Maternal BMI <18, BMI >40
  • Smoking
  • Alcohol
    • Can cause fetal alcohol syndrome
  • Illicit drugs
  • Non-steroidal
  • Excessive Caffeine?
  • Fever during pregnancy
  • Celiac Disease
Fetal alcohol syndrome is the term given to a set of physical, mental and neurobehavioral birth defects caused by maternal alcohol consumption, during pregnancy

Signs and Symptoms

Clinical Presentation

  • PV bleeding
  • Lower abdominal pain
  • Finding on Ultrasound

Importance of early bleeding in pregnancy:

  • Potentially life threatened if ruptured ectopic
  • Loss of viable pregnancy
  • Even if viable – increased risk of adverse outcome → miscarriage, prematurity, premature rupture of membranes, intrauterine growth restriction (IUGR)

Examination –

  • General observation – shock?
  • Abdominal tenderness?
  • Speculum examination
    • Is the cervical open or closed?

Differential Diagnosis

  • Miscarriage
  • Ectopic Pregnancy
  • Gestational trophoblastic disease
  • Implantation bleed (physiological) -Diagnosis of exclusion. Characterised by small amount of spotting or bleeding 10-14 days post- fertilization. therefore around time of missed menstrual period.
  • Cervical pathology
  • Vaginal Pathology
  • Uterine Pathology
  • Subchorionic haematoma (placenta abruptio)
Gestational Trophoblastic Disease An unusual type of abnormal pregnancy also known as molar pregnancy, which is trophoblastic tissue, or placenta-like tissue, usually without a fetus. The clinical presentation of molar pregnancy is vaginal spotting, absence of fetal heart tones, size greater than dates, and markedly elevated HCG levels.
Remember With any early pregnancy bleeding rule out ectopic pregnancy

Investigations and Diagnosis

Investigation

  • b-HCG (normal pregnancy at least 1500IU/L, repeatable trend)
  • Abdominal and PV ultrasound
Remember if a live embryo s seen on ultrasoundscan and the cervix is closed, the is reassired and follow-up is orgnaised. Complex platient may require serial β-hCG

Other Investigations

  • Fetal Doppler if estimated gestation is 10-12 weeks at least
  • FBC (anaemia, infection)
  • Cross match and group & hold (potential resus + surgical management)
  • Rhesus status – anti-D required if Rh-
  • Serology if indicated

Diagnosis Transvaginal ultrasound and beta-hCG supported by clinical evaluation

Aetiology

Remember Miscarriage is most commonly caused by chromosomal abnormalities in the embryo or exposure to teratogens. Very difficult to tell what cause was in each individual case

Fetal Factors

  • Chromosomal abnormalities
  • Congenital abnormalitires
  • Trauma

Maternal factors

  • Age
  • Structural factors – uterine
  • Diabetes with poor glycemic
  • TORCH
  • Exposure to teratogens
  • Fever

Types of Miscarriage

Investigation – to identify a miscarriage and to differentiate between the types

  • PV examination – is the cervix open of closed?
  • Ultrasound to check for fetal heart rate

Types of miscarriage

  • Threatened miscarriage
    • Presentation with PV bleeding during pregnancy is threatened until proven otherwise.
    • Light bleeding and spotting, cervix closed. Can become normal or progress to miscarriage. Do investigation
  • Inevitable
    • Lower abdo pain with vaginal bleeding
    • Cervix open on speculum -> will die
    • Ultrasound fetal heart rate +/- -> will die and pass through cervix
  • Incomplete
    • Cervix is open
    • Ultrasound non-viable intrauterine pregnancy (fetus died)
  • Complete
    • Products have passed
    • Cervix closed
    • Ultrasound shows nothing in uterus.
  • Missed/delayed miscarriage
    • Diagnosed in ultrasound incidental without symptoms of miscarriage.
    • They can stop having morning sickness
    • Examination uterus is smaller
    • Ultrasound absent of fetal heart rate
  • Recurrent
    • 3 or more consecutive miscarriages → Requires investigation

Management

Conservative/expectant management

  • Not bleeding much
  • Watch and wait
  • Present back in 1-2 weeks
  • Pain relief – NSAIDS and warm pack

Medical management – Prostaglandins

  • Best suited for early pregnancy
  • Induce uterine contraction -> passing of products
  • 15% failure rate
  • Can continue to have bleeding for up to 3weeks
Pharmacology Prostagladin analogues (misoprostol) work by induce uterine contractions and evacuate uterus contents

Surgical management

  • Failed medical management
  • Very heavy bleeding
  • Late miscarriage
  • Septic miscarriage
  • Dilatation and curettage (D&C)
Remember Miscarriage can be very distressing for both the mother and partner. Consider support and counseling.
Dilatation and curettage refers to the dilatation of the cervix and scrapping of the parts of the uterine lining. It is both therapeutic and treatment for miscarriage.

Complications and Prognosis

Complications

  • Depression – miscarriage can be devastating  and distressing

Complication of Surgical Management of Miscarriage

  • Infection
  • Haemorrhage
  • Uterine perforation
  • Retained products of conception
  • Intrauterine adhesions
  • Cervical tears

Prognosis

  • Risk of another miscarriage
    • After 1 miscarriage – same risk as general population
    • After 2 miscarriage – 25%
    • After 3 miscarriage (Recurrent) – 40%
Side note Women with recurrent miscarriage should be referred to specialised services with expertise in dealing with recurrent pregnancy loss