2 Cervix in Pregnancy Flashcards
3 Methods to Assess the Cervix
- Transabdominal
- Tanslabial
- Transvaginal
For a Transabdominal approach what patient prep is required?
Full bladder
Why is a over distended bladder not good?
Can falsely elongate the cervix
squish with posterior uterine segment
Where doe scanning take place on the patients body?
above public bone, make sure parallel to long axis or may be foreshortening it.
As baby grows harder for which approach?
Transabdominal
What is another reason the cervix can look elongated?
Uterine Contraction
What type of scanning approach is used when ruptured memembranes have occured?
Translabial
What is another reason to perform translabia approach?
Placenta previa
No EV due to uterine infection
What is the patient prep for translabia exam?
Empty bladder
What is a limitation for the translabia exam?
Gas in the rectum obscuring the external os
Which probe is used for translabia and how is it performed
Curvilinear with probe cover, placed in SAG plane between labia.
What kind of frequency probes are used?
Low frequency probe
As cervix is further away from probe in this approach
What is the gold standard exam for assessing the cervix?
EV scanning (transvaginal)
Translabial and EV length measurement of CX are often similar or not?
YES
Transvaginal method inserts the probe ____ cm into vagina
3-4 cm
Transvaginal method is contraindicated with?
ruptured membranes (causing infection)
Transvaginal method can cause?
bleeding or contractions or preterm labour
what doe the normal Cervix look like in appearance
Echogenic canal (can appear hypo on some occsion)
What is the lower limit of normal of cervix length?
30mm (3 cm)
<15 mm (1.5cm) cervix length corresponds with
50% effacment (thinning cervix, getting ready for delivery)
<10 mm (1.0cm) cervix length corresponds with
75% effacment (thinning cervix, getting ready for delivery)
What does the normal Cervix look like in pregnancy?
Echogenic line in cervix canal = the mucus plug
surrounded by hypoechoic area = membrane
(just seeing the hypoechoic area is normal too)
The measurement of CX should extend from ?
Internal os to the external os
What should the measurement be from the internal to the external os
> 3 cm
What is funneling?
Herniation of the fetal membrane into the internal os.
What does the external os look like in funneling?
IT REMAINS closed
Why is Ultrasound important for funneling?
It can detect early signs of incompetent service
What does funneling have an increased risk of?
Preterm delivery (note: some carry to term without intervention)
What size herniation into cervical canal is considered abnormal and seen with EV
AP >5mm before 30 weeks
What can be confused with cervical incompetence?
Contraction of the lower uterine segment
What is cervical Incompetence
Dynamic process where the CX changes spontaneously and dramatically in a short period of time
When does cervical incompetence occur?
When CX unable to retain a pregnancy to full term
cervical incompetence can be aquired due to ______ or excessive dilation with a ________-
laceration(deep cut); D & C
cervical incompetence can also be the result of a?
congenital anomaly, where UT misshapen
What is the classic presentation of cervical incompetence
Painless cervical dilation
cervical incompetence has a history of recurrent?
2nd trimester losses
What are is the DDX of cervical incompetence
Preterm labour
What does preterm labour cause that can dilate the cervix?
Contractions
What is the treatment for cervical incompetence ?
Cervical cerclage (string suture)
When is a Cervical cerclage inserted? (weeks)
13-16 weeks
What are the increased risk of Cervical cerclage (2)
- Amnionitis
2. rupture of membranes
What does the Cervical cerclage look like sonographically?
ecogenic foci (linear) with shadows, surrounding anterior and posterior portion of the CX
When is the Cervical cerclage placed in /Timing?
After bulging membranes occurs
what % pregnaancy loss rate does Cervical cerclage have?
30%
What is used to assess placement and funneling above and below Cx?
Ultrasound
What is preterm labour?
Labour and/or Delivery before 37 weeks
How often does preterm labour happen in pregnancy? (%)
5-10% of all pregnancies
What are other names for Cervical cerclage (2)
Shirodkar suture
McDonald “”
