1. Progesterone and Preterm birth
Prevention
2 SEPARATE INDICATIONS
INDICATIONS DETERMINE CHOICE OF THERAPY
MAY 2012
17alpha-hydroxyprogesterone caproate(17-P)
VAGINAL GEL 90 MG OR 200-mg SUPPOSITORY

2. SAFETY
• Follow-up, at a mean of 4 years, of 278
children randomized in the largest RCT
evaluating 17P for prevention of recurrent PTB
revealed no differences compared to placebo
Regarding:
• Physical examination
• Health status
• Performance (motor, problem solving,
personal, social).
• Obstet Gynecol 2007;110: 865-72. NICHD

3. Current Society for Maternal-Fetal Medicine recommendations
regarding use of progestogens for prevention of preterm birth
• Singletons with prior SPTB 17P 250 mg IM
weekly from 16-20 wk until 36 wk
• Singletons without prior SPTB but CL 20 mm
at 24 wk Vaginal progesterone 90-mg gel or
200-mg suppository daily from diagnosis of
short CL until 36
• Multiple gestations No evidence of
effectiveness

4. Previous PTD < 36 wks
Second Trimester Loss ( 12-22wks)
• PTD 16 TO 36 weeks Start 17 P @ 16 weeks continue until 36 completed
weeks.
• Serial cervical lengths start @ 16 weeks & continue every 2 weeks UNTIL
24 0/7 WEEKS. CERVICAL LENGTH If >/= 35 mm continue every two weeks
until 24 0/7 weeks.
• If CERVIVCAL LENGTH is 25-34 mm continue serial cervical lengths every 1
WEEK vs 2 weeks UNTIL 24 0/7 WEEKS
• If cervix is < 25 mm these patients may benefit from cerclage up to 24 0/7
weeks. ( OWEN RCT 2009 AJOG). If < 15 mm they will gain the most
benefit from cerclage.
• If idiopathic (ie c/w incompetent cervix) previous second trimester loss
from 12-22 weeks these patients should have strong consideration for
history indicated cerclage.

5. Incidental Short Cervix
No previous PTB
• Singleton gestations and TVU CL 15 mm or less
at 20-25 weeks, vaginal progesterone 200 mg
nightly started at 24 weeks until 34 weeks
• IN women without prior PTB benefit of 200
mg progesterone in preventing PTB < 34
weeks (RR, 0.54; 95% CI, 0.34 – 0.88).
• IF TVU CL 15 , the number of women needed
to treat to prevent 1 PTB < 34 weeks is about 1
IN 7
FONSECA et.al;N Engl J Med 2007;357:462-9.

6. Incidental Short Cervix
No previous PTB
• Singleton gestations without PTB and TVU CL
10 mm -20 mm at vaginal progesterone 90-mg
gel daily started at 20-23 6/7 weeks until 36
6/7 weeks preventing PTB < 33 weeks (8% vs
15%; RR,0.50; 95% CI,0.27– 0.90)
• Once a TVU CL 10-20 mm is identified, the
number needed to treat to prevent 1 PTB < 33
weeks is about 1 IN 14.
Hassan et.al;Ultrasound Obstet Gynecol 2011;38:18.

7. Incidental Short Cervix
No previous PTB
• In a metaanalysis, including 554 singleton
gestations, with no prior PTB, and TVU CL < 25
mm < 25 weeks
• Vaginal progesterone 90 mg was associated
with a significant reduction in PTB < 33 weeks
(RR, 0.60; 95% CI,0.39 – 0.92)
Romero et.al;Am J Obstet Gynecol 2012;206:124.NIH

8. 200 mg Suppository OR 90mg GEL
No clearly Superior Therapy
• FIRST INDICATION
• NO prior HISTORY OF PTB
• INCIDENTAL SHORT CERVIX = 10 mm-20 mm TVCL
• 20 mm is 5th percentile
• 25 mm is 10th percentile
• Vaginal Progesterone is associated with reduction in PTB
and composite perinatal morbidity and mortality.
• Based on these results if a TVU CL 10-20 mm is identified
at 24 weeks OR LESS
• Vaginal Progesterone ( 90 mg GEL OR 200 mg suppository)
can be offered for prevention of PTB.
• RR ~0.55 FOR PTB PREVENTION <34 WEEKS
• SMFM Clinical Guideline MAY 2012

9. 17P FOR PRIOR PTB
• Although limited data is available comparing the different
preparations of progestogens
• CURRENTLY stronger evidence of effectiveness for 17P VS. vaginal
progesterone, IN WOMEN WITH PRIOR PTB , based on the 2
largest trials.
• Therefore, 17P 250 mg IM weekly starting at 16-20 weeks until 36
weeks should be recommended to women with singleton
gestations and Prior PTB @ 20-36 6/7 weeks.
• Consider cerclage for cervical length < 25 mm.
O’brien et.al; Ultrasound Obstet Gynecol 2007;30:687-96
Meis et.al; N Engl J Med 2003;348:2379

10. INCIDENTL SHORT CERVIX
</= TO 20 MM < 24 WEEKS
• Singletons without prior PTB but WITH
Vaginal CL </=20 mm at < 24 wk
• Progesterone 90-mg gel
• Micronized progesterone 200-mg suppository
• Daily from diagnosis until 36 WEEKS
• < 10 MM CONSULT MFM
• SMFM Clinical Guideline MAY 2012