Miscarriage_Epidemiology_Flashcards
What is the definition of an abortion?
An abortion is the expulsion of the products of conception before 24 weeks. The term miscarriage is used often to avoid any misunderstandings.
What percentage of diagnosed pregnancies will miscarry in early pregnancies?
15-20% of diagnosed pregnancies will miscarry in early pregnancies.
What is the incidence of non-development of the blastocyst within 14 days?
Non-development of the blastocyst within 14 days occurs in up to 50% of conceptions.
What percentage of women are affected by recurrent spontaneous miscarriage?
Recurrent spontaneous miscarriage affects 1% of women.
summarise
Miscarriage: epidemiology
An abortion is the expulsion of the products of conception before 24 weeks. The term miscarriage is used often to avoid any misunderstandings
Epidemiology
15-20% of diagnosed pregnancies will miscarry in early pregnancies
non-development of the blastocyst within 14 days occurs in up to 50% of conceptions
recurrent spontaneous miscarriage affects 1% of women
**A 34-year-old, G2P1, is referred to the obstetrics assessment unit by her general practitioner for mild abdominal pain and vaginal bleed. She is 15 weeks pregnant.
Which one of the following in her history might make you worry about a miscarriage?
Exercise
Primigravid
Previous Caesarian section
Large cervical cone biopsy
Sexual intercourse
**
Large cervical cone biopsy
Large cervical cone biopsy is a risk factor for 2nd-trimester miscarriage
The rest of the options are not risk factors for 2nd-trimester miscarriage.
A 24-year-old primigravida patient presents to the emergency department with a 2-day history of light per-vaginal spotting. According to her last menstrual period date, she is 8 and a half weeks gestation and has not yet had any scans.
She denies any abdominal pain or flooding episodes. She has no past medical history. A transvaginal ultrasound scan shows a closed cervical os with a single intrauterine gestational sac, a 2mm yolk sac, and a crown-rump length measuring 7.8mm, with no cardiac activity.
What is the most likely diagnosis for this patient?
Complete miscarriage
Inevitable miscarriage
Missed miscarriage
Partial miscarriage
Threatened miscarriage
Missed miscarriage
A transvaginal ultrasound demonstrating a crown-rump length greater than 7mm with no cardiac activity is diagnostic of a miscarriage
Important for meLess important
This is a missed miscarriage. The patient has had an early pregnancy scan that shows an intrauterine foetus of a size in keeping with around 6 weeks gestation, with no cardiac activity. Given that cardiac activity begins around week 5 of gestation, these results indicate that the foetus has died. With the history of spotting and the closed cervical os, this is a missed miscarriage. ‘Missed’ refers to the fact that the os remains closed and the gestational sac remains within the uterus.
A complete miscarriage is not correct here. This diagnosis is used if a patient has had a previous ultrasound confirming a viable intrauterine pregnancy, then vaginal bleeding, and then a subsequent ultrasound indicating no evidence of retained products of conception or a gestational sac once bleeding has stopped. As the vignette shows a gestational sac and products of conception in the uterus, this is not the correct answer.
An inevitable miscarriage is diagnosed if the cervical os is open and there is heavy vaginal bleeding. The use of ‘inevitable’ means that nothing can be done to stop the miscarriage from occurring, as the os is open.
A partial miscarriage does not exist as a formal definition.
Threatened miscarriage is a confusing term and can be concerning for women presenting with vaginal bleeding. It is used when patients present with vaginal bleeding but have a viable intrauterine pregnancy with cardiac activity on ultrasound. As the vignette shows an absence of cardiac activity, this is an incorrect answer.
missed miscarriage buzz words
per-vaginal spotting
painless
closed cervical os
intrauterine gestational sac
yolk sac
crown-rump length measuring >7mm
no cardiac activity.
A pregnant woman at 11 weeks gestation has a miscarriage. Of these five factors, which one is most associated with miscarriage?
Obesity
Bumping the abdomen
Having sex
Heavy lifting
Stress
Obesity
Obesity is the answer here because it is the only one of these factors that has been linked to miscarriage. The other factors are not associated with miscarriage.
Factors that are associated with an increased risk of miscarriage are:
Increased maternal age
Smoking in pregnancy
Consuming alcohol
Recreational drug use
High caffeine intake
Obesity
Infections and food poisoning
Health conditions, e.g. thyroid problems, severe hypertension, uncontrolled diabetes
Medicines, such as ibuprofen, methotrexate and retinoids
Unusual shape or structure of womb
Cervical incompetence
Factors that have not been associated with an increased risk of miscarriage are:
Heavy lifting
Bumping your tummy
Having sex
Air travel
Being stressed
