Transcript Diagnosis of PTL

Diagnostic Techniques for
Pre-Term Labor
Ch 13
2009-2010 Academic Year
MSIII Ob/Gyn Clerkship
Self-Directed Study
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Diagnosis of PTL
• Objectives - Understand the diagnostic
techniques for PTL
– Definition
– Cervical Length
– FFN
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Definition
• Between 20 and 37 weeks EGA
• Documented uterine contractions (4
per 20 minutes or 8 per 60 minutes)
• Documented cervical change
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Normal Cervical Length
Bladder
Cervix
Intrauterine
http://www.scielo.br/img/revistas/bjmbr/v37n5/4786i02peq.jpg
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Cervical Length
Normal Cx Length
No Funneling
www.Mdconsult.com
2009-2010
• Measure length of
cervix using transvaginal ultrasound
• Greater than 2.5 to
3 cm is considered
normal (references
differ) Best PPV if
use 3 cm as cutoff.
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Shortened Cervix
• Less than 2 cm with
high PPV for PTL
• Can be affected by
bladder (full vs.
empty), want empty
• Change vs. stability
over time - if 2.5 cm
but no change, may
not be PTL
http://www.studiolift.com/fetal/site/Short%20cervix.jpg
9mm is not normal for CL
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Funneling and PTL
Funneling present
• Funneling
• Present when patient
valsalva’s or with
fundal pressure by
sonographer
• Residual length is
important
https://vss121.viux.com/iame_com/learning/cervlength/figure7.jpg
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies
Fetal Fibronectin (FFN)
• Very good NPV (Neg test
result consistent with no
Posterior Fornix
delivery within 7 days)
PPV not as good (can be
FFN is presesnt
false positive)
when cervix starts
• Blood can give false
to change.
positive. If speculum,
cervical exam, intercourse
No gel on speculum
(anything in vagina) in past
24 hours, can give false
results, so cannot be done
http://www.laboratoryalliance.com in those circumstances.
2009-2010
USUHS MSIII Ob/Gyn
Clerkship Self Directed Studies