What is the definition of miscarriage?

Miscarriage is a loss of your baby before 20 weeks of pregnancy. Additionally, if the length of pregnancy is unclear, a baby born with no signs of life and weighing less than 400 grams is considered a miscarriage.

What is the difference between stillbirth and miscarriage?

  • Stillbirth- refers to the birth of a baby who has died before delivery when the pregnancy has progressed for more than 20 weeks
  • Miscarriage- a pregnancy that ends, on its own, before 20 weeks of gestation 

What is the difference between early miscarriage and late miscarriage?

  • Early miscarriage- loss of pregnancy before 12th week of pregnancy (first trimester)
  • Late miscarriage- loss of pregnancy occurs between week 12-20 of pregnancy (second trimester)

Prevalence of miscarriage

It is estimated that 10-25% of clinically recognized pregnancies will result in a miscarriage. Most miscarriages occur within the first 13 weeks of pregnancy. 

Why do miscarriages occur?

The reasoning for miscarriages vary, but often times cannot be identified. The most common cause is chromosomal abnormality. This means that something is not correct with the baby's chromosomes. A damaged egg or sperm cell typically causes this chromosomal abnormality. 

Some additional possible causes of miscarriage include, but are not limited to:

  • Increased maternal age
  • Maternal trauma
  • Hormonal problems, infections or maternal health problems
  • Lifestyle (smoking, drug use, malnutrition, excessive caffeine, exposure to radiation or toxic substances)
  • Implantation of the egg into the uterine lining does not occur properly

A woman who has had a previous miscarriage has a 25% chance of having another miscarriage. This is only a slightly elevated risk from a woman who has not had a previous miscarriage. 


Types of Miscarriage

Ectopic pregnancy:

This situation happens when a fertilized egg implants outside the uterus, most commonly in the fallopian tube. Rapid treatment is necessary to stop the development of the implanted egg. Serious maternal complications can occur if left untreated. Symptoms including severe pain in lower abdomen, vaginal bleeding, vomiting or pain in the tip of one shoulder have occurred.

Molar pregnancy:

A molar pregnancy is the result of a genetic error during the fertilization process. This leads to abnormal tissue growth in the uterus. An embryo rarely develops in a molar pregnancy, but surgical removal is often necessary if this occur. Typically symptoms of pregnancy usually occur with molar pregnancies including a miss period, positive pregnancy test and severe nausea. 

Blighted ovum:

Also called an embryonic pregnancy. A fertilized egg implants into the uterine wall, but the fetus never begins to develop. There is often a gestational sac with or without a yolk sac, but fetal growth does not occur. 



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