UTERUS & OVARIES

CX US


always use TVS due to :
fetal parts obscure CX/ UB filling elongates cx & mask funnel/ long distance from the probe/ manual pressure/no cinical decision should be based on TAS alone especially in preterm birth (PTB)/difficult to see external os/difficult to obtain adequate image
     TVS is very close to the cx/ no UB filling/ no obstruction to fetal parts/ TVS is the gold standard
TVS technique
1/ pt empty UB
2/ use plenty jell on probe
cover probe with condom /3
4/ again plenty jell on codom
5/ let pt insert probe into anterior fornix
6/ obtain saggital with echogenic endocervical mucosa along the length of the cervical canal
7/ withdraw probe until blurred
8/ enlarge image 2/3 of screen
9/ measure from external os to internal os along endocervical canal
10/ obtain 3 measurements, use shortest best view of the whole cx
11/ apply transfundal pressure for 15 seconds
12/ total exam at least 5 mins
uterine cervix is about 2.5 cm in length in the NONgravid ...In the late second and early third trimester the cervical length measures anywhere between 3 cm to 3.5 cm (30-35mm) and decreases progressively as the pregnancy advances, in preparation for labor
Mid pregnancy cervical length measurement is useful in predicting the possibility of vaginal delivery in women with cervical length between 2.1 and 3cm and risk of cesarean section in women with long cervix of more than 4 cm
The mean cervical length at 24 weeks is about 35 mm when measured by transvaginal ultrasound. A short cervix is defined as a cervix that is less than 25 mm which may be indicative of preterm birth