Week 2 Flashcards
(31 cards)
When is the GS visible?
4 weeks and 3 days
When is the YS visible?
5 weeks
What is seen in week 8?
- Fetal pole and YS
- Fetal movements
- Limb buds
- Rhombencephalon
- Amniotic membrane
When might you see a physiological exomphalos?
Typically between weeks 8-12 with the exomphalos resolving by week 12
What is important when imaging an early gestational sac?
Ensuring a clear distinction between a true gestational sac and intra-cavity fluid
What can cause intracavitary fluid?
- Hormonal changes
- infections
- physiological menstruation
What should you do if the gestational sac is not present with a positive pregnancy test?
- Looks for ectopic pregnancies
When would you report a PUL (pregnancy of unknown origin)?
PUL refers to where there is a positive pregnancy test but an intrauterine or ectopic pregnancy cannot be visualized on TV US.
- Positive BHGC with no IU GS
- when a structure that cannot be clearly identified as an IUP, or EP
- No signs of RPOC
What are the ASUM and ASA criteria for fetal demise?
ASA:
1. Presenting without an embryo or yolk sac, and mean gestational sac diameter ≥25 mm.
2. Presenting with an embryo with no heart activity, and crown-rump length ≥7 mm
ASUM:
1. When the MSD is ≥25 mm with no visible yolk sac or embryo; or
2. When there is a visible embryo with CRL ≥7mm but no cardiac activity can be demonstrated.
The area of the embryonic heart should be observed and recorded with M-Mode or cine clip
if possible. The area of the embryonic heart should be observed for a prolonged period of at
least thirty (30) seconds to ensure that there is no cardiac activity.
What are the ASA and ASUM criteria for follow-up fetal demise?
ASA:
- No visible embryo (with or without YS) with GS diameter >12mm and after >7days no embryo with cardiac activity
- No visible embryo (with or without YS) with GS diameter <12mm and after >14days no embryo with cardiac activity and GS diameter has not doubled.
- Visible embryo without cardiac activity and still no cardiac activity after >7days
ASUM:
- Initial scan showed fetal pole <7 mm with no cardiac activity beat and a repeat scan >7 days also shows no cardiac activity
- Initial scan showed a MSD ≥12 mm with no embryo and a repeat scan >7 days does not show interval development of yolk sac or an embryo with cardiac
activity - Initial scan showed a MSD <12 mm with no embryo and a repeat scan in >14 days shows no visible yolk sac or cardiac activity and the MSD has not doubled
- YS is visible on initial scan and there is no embryo with a heartbeat after 11 days
- absence of cardiac activity, which was seen to be present on an earlier scan.
What is the purpose of a nuchal transluceny measurement?
- Assess the risk of chromosomal abnormality (trisomy 21)
- Can also suggest fetal anomalies (congenital heart disease) if NT is abnormal
What is an abnormal NT measurement?
> 3mm
Define menstrual age
Menstrual Age (also known as Gestational Age) is the age of a pregnancy calculated from the first day of the woman’s last menstrual period (LMP).
Define gestational age
The true gestational age, based on the date of fertilisation, is two weeks less than the menstrual age because fertilisation occurs about two weeks after the first day of menstruation.
Define fetal growth
The rate of which the fetus is growing
Define LGA
The fetus is growing at a rate faster than expected and the number of weeks the mother has been pregnant. The fetus is >90th percentile.
Define IUGR
The fetus is not developing according to GA and is smaller than the expected size according to the patient’s weeks of pregnancy.
Define macrosomia
The fetus is large post term than expected
Define spontaneous termination of pregnancy, explain its classification and recognise its clinical presentations.
Spontaneous termination of pregnancy represents a miscarriage/abortion and denotes the expulsion of conception before viability. The most common time for a miscarriage is between 8-13 weeks, but after 10 weeks is less likely for a spontaneous miscarriage. Etiological factors can include, zygote malformation, immunological factors, general disease of the mother, uterine abnormalities, hormonal insufficiency, however, the cause of most miscarriages are uncertain.
Explain threatened miscarriage
- Bleeding in the choriodecidual space, but not sufficient to cause embryonic demise.
- Unexpected and usually painless blood loss.
- The cervix is closed and the uterus is appropriately sized for gestation.
- Abortion does not always follow. More than 95 percent of women with a viable pregnancy (cardiac activity visualised) will continue to term uneventfully.
- The onset of painful contractions and increased loss may herald dilation of the cervix, and mean that the miscarriage is becoming inevitable.
- No treatment has been demonstrated to alter the prognosis in threatened miscarriage.
Explain inevitable miscarriage
- Cervix dilates
- Bleeding usually increases and strong contractions may follow.
- Becomes complete if the entire contents of the uterus are extruded.
Explain Complete miscarriage
- All the products of conception have been expelled.
- Pain is absent and bleeding is slight.
- The cervix has closed again.
Explain Incomplete miscarriage
- Part of the products of conception have been passed but some have been retained.
- The amount of bleeding varies, but it can be severe enough to cause hypovolemic shock.
- If there is still bleeding a week after a miscarriage that was thought to be complete, it is more likely that it is incomplete.
Explain Septic miscarriage
Infection can follow incomplete abortion and it is then referred to as septic miscarriage.
