SOGC TECHNICAL UPDATE SOGC TECHNICAL UPDATE The Use of Progesterone for Prevention of Preterm Birth
represents an abstraction of the evidence rather than a
This technical update has been reviewed by the Maternal Fetal
methodological review. The level of evidence and quality of
Medicine Committee and approved by the Executive of the Society
recommendations are described using the criteria and
of Obstetricians and Gynaecologists of Canada.
classifications of the Canadian Task Force on Preventive HealthCare (Table 1). PRINCIPAL AUTHORS Values: This update is the consensus of the Maternal Fetal Medicine
Committee of the Society of Obstetricians and Gynaecologists of
Benefits, Harms, and Costs: Counselling the patient at increased
risk for PTL should include consideration of the potential benefits
MATERNAL FETAL MEDICINE COMMITTEE
of progesterone use and our lack of/limited knowledge of many
neonatal outcomes and optimal dosing. Sponsor: Society of Obstetricians and Gynaecologists of Canada. Recommendations
1. Women at risk for PTL should be encouraged to participate in
studies on the role of progesterone in reducing the risks of pretermlabour. (I-A)
Savas Michael Menticoglou, MD, Winnipeg MB
2. Women should be informed about the lack of available data for
many neonatal outcome variables and about the lack of
Lynn Carole Murphy-Kaulbeck, MD, Allison NB
comparative data on dosing and route of administration. Women
with short cervix should be informed of the single large RCTshowing the benefit of progesterone in preventing PTL. (I-A)
3. Women and their caregivers should be aware that a previous
preterm labour and/or short cervix (< 15 mm at 22–26 weeks’
gestation) on transvaginal ultrasound could be used as anindication for progesterone therapy. The therapy should be startedafter 20 weeks’ gestation and stopped when the risk of prematurityis low. (I-A)
4. On the basis of the data from the RCTs and meta-analysis, it is
Abstract
recommended that in cases where the clinician and the patienthave opted for the use of progesterone the following dosages
Objective: To introduce new information on the use of progesterone
to prevent premature labour and to provide guidance to obstetrical
• For prevention of PTL in women with history of previous PTL:
caregivers who counsel women on the merits of this choice
17 alpha- hydroxyprogesterone 250 mg IM weekly (IB) or
Options: This discussion is limited to progesterone therapy for
progesterone 100 mg daily vaginally. (I-A)
prevention of preterm labour (PTL) in women at increased risk of PTL.
• For prevention of PTL in women with short cervix of < 15 mm
Evidence: A search of both Medline and the Cochrane Library
detected on transvaginal uktrasound at 22–26 weeks
identified the most relevant medical evidence. This document
progesterone 200 mg daily vaginally. (I-A)
Key Words: Preterm labour, progesterone, short cervix, prematurity This technical update reflects emerging clinical and scientific advances as of the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed. Local institutions can dictate amendments to these opinions. They should be well documented if modified at the local level. None of these contents may be reproduced in any form without prior written permission of the SOGC.
JANUARY JOGC JANVIER 2008 l SOGC TECHNICAL UPDATE Table 1. Key to evidence statements and grading of recommendations, using the ranking of the Canadian Task Force on Preventive Health Care
Evidence obtained from at least one properly randomized
A. There is good evidence to recommend the clinical preventive
II-1: Evidence from well-designed controlled trials without
B. There is fair evidence to recommend the clinical preventive
II-2: Evidence from well-designed cohort (prospective or
C. The existing evidence is conflicting and does not allow to
retrospective) or case-control studies, preferably from more
make a recommendation for or against use of the clinical
preventive action; however, other factors may influencedecision-making
II-3: Evidence obtained from comparisons between times or
places with or without the intervention. Dramatic results in
D. There is fair evidence to recommend against the clinical
uncontrolled experiments (such as the results of treatment
with penicillin in the 1940s) could also be included in this
E. There is good evidence to recommend against the clinical
III: Opinions of respected authorities, based on clinical
There is insufficient evidence (in quantity or quality) to make
experience, descriptive studies, or reports of expert
a recommendation; however, other factors may influence
*The quality of evidence reported in these guidelines has been adapted from The Evaluation of Evidence criteria described in the Canadian Task Forceon Preventive Health Care.30†Recommendations included in these guidelines have been adapted from the Classification of Recommendations criteria described in the The CanadianTask Force on Preventive Health Care.30
INTRODUCTION
is more complex than in other animals and that progester-
Preterm birth remains a major clinical problem. Preva- one may have a more limited role than in animal models.6
lence in Canada increased from 6.3% of live births in
Recently several studies on the use of progesterone to pre-
1981–1983 to 6.6% in 1991 and 7.6% in 2000,1,2 although a
vent preterm labour have been published. The purpose of
large portion of this increase is related to multiple pregnan-
this paper is to evaluate the information in these studies and
cies. There are very few interventions that improve the
outline the current role for the use of progesterone for this
prognosis of preterm labour. The use of antenatal
corticosteroids was shown consistently to have such aneffect,3 but most studies on tocolysis, with the exception of
DATA ON PROGESTERONE AND PRETERM LABOUR
one recent paper on nitroglycerin,4 had very limited clinical
Many studies have examined the use of progesterone for
use. Almost 50 years ago, Csapo et al.5 promoted the pro-
prevention of preterm labour. Mackenzie et al.7 found 735
gesterone see-saw theory, which is that high progesterone
such studies, but only three were appropriate for inclusion
levels prevent uterine contractions and low levels facilitate
in their meta-analysis on therapy in the second trimester,
such contractions. This is one reason for the use of proges-
which showed that the use of progestins in women at risk
terone therapy in early pregnancy and the use of RU486, a
for preterm labour reduced its occurrence by 43% (RR 0.57
progesterone antagonist, to induce abortions. It seems that
[0.36–0.90]). Similar reduction of preterm births prior to 35
the hormonal control of contractions and labour in humans
weeks (33%) and 32 weeks (42%) was found. Two othermeta-analyses by Sanchez Ramos et al.8 and Dodd et al.9were completed recently. Dodd et al. concluded thatwomen who received progesterone were statistically signifi-
ABBREVIATIONS
cantly less likely to give birth before 37 weeks (RR 0.58;95% CI 0.48–0.70), to have an infant with birth weight of
American College of Obstetricians and Gynecologists
> 2.5 kg (RR 0.62; 95% CI 0.49–0.78), or to have an infant
diagnosed with intraventricular hemorrhage (RR 0.25; 95%
CI 0.08–0.82). Their analysis showed no apparent benefit to
early start of the progesterone administration or in the use
of higher doses. Sanchez-Ramos et al. selected 10 papers for
l JANUARY JOGC JANVIER 2008
The Use of Progesterone for Prevention of Preterm Birth
Table 2. Study characteristics (adapted from Dodd et al.9)
analysis, and their results were similar to those of the two
3. Neonatal Outcome
other meta-analyses. The characteristics of these studies
The use of progesterone contributes to a significant reduc-
and more recent RCTs are outlined in Table 2.
tion in low birth weight and intraventricular hemorrhage.
Reviews and meta-analysis on the topic published prior to
Further data are needed to demonstrate a significant reduc-
2000 differed in methodology and inclusion criteria from
tion in the following outcomes: perinatal death, respiratory
one another. None of them included the latest RCTs
distress syndrome, necrotizing enterocolitis, patent ductus
reviewed here. Daya et al.19 looked at the use of progestins
arteriosus, sepsis, and retinopathy of prematurity, as the
to prevent losses in women who had recurrent losses.
current studies and the meta-analysis are underpowered to
Kierse et al.20 limited their analysis to therapy with 17
alpha-hydroxyprogesterone, and the review by Goldsteinet al.21 included studies on women at low risk for PTL. The
4. Safety
studies by Daya et al. and Kierse et al. (but not the study by
Progesterone has been used extensively and safely in the
Goldstein et al.) showed some benefit in using progester-
first trimester, when the fetus is more vulnerable for luteal
one. Other publications on cervical length changes and PTL
phase insufficiency and recurrent losses. To date, no data
from RCTs and other studies for prevention of preterm
The main results of the RCTs outlined above are provided
birth indicate this therapy is not safe aside from a single
retrospective study28 that showed that the incidence of ges-tational diabetes was 12.9% in women treated with 17P
SUMMARY OF THE CURRENTLY AVAILABLE DATA
group (n = 557) compared with 4.9% in control subjects(n = 1524, P < 0.001; OR 2.9 [95% CI 2.1–4.1]). 1. Prevention of PTL The summary of data presented above indicates that admin- 5. Route of Administration and Dosage
istration of progesterone in the second trimester to women
There are no data comparing routes of administration or
with short cervix or with a previous history of preterm
dosing regimens. The meta-analysis of Dodd et al.9 did not
labour may reduce their risk for preterm birth. This modi-
show an added benefit of progesterone use prior to
fies the sole indication of PTL outlined in the ACOG tech-
20 weeks’ gestation. A recent RCT reached the same
nical bulletin of 2003.25 The ACOG guideline cautiously
recommends the use of progesterone exclusively in womenwith previous preterm labour. 6. Need for Further Research
There are still large gaps in our knowledge. More data are
2. Frequency of Use
required to properly evaluate the impact on neonatal out-
The frequency of progesterone use based on the ACOG
comes. More information is needed on formulation (17
recommendations increased in the US from 38% in 2003 to
alpha-hydroxyprogesterone vs. progesterone), route of
67% in 2005.26 In contrast, a recent Canadian study27
administration (IM vs. vaginal or oral), and the optimal dos-
showed that only 7% of Canadian obstetricians were using
age for progesterone use. More research is required to pro-
progesterone for the prevention of PTL in 2004.
vide definitive data on the potential rare risks associated
JANUARY JOGC JANVIER 2008 l SOGC TECHNICAL UPDATE Table 3. Outcomes of studies
RR for B-weight < 2500 gm RR for perinatal mortality
Table 4. Meta-analysis of neonatal clinical outcomes from six randomized trials that compared intramuscular progesterone with placebo
with progesterone administration. Currently, there is at least
cervix (< 15 mm at 22–26 weeks’ gestation) on
one RCT (The PROGRESS study) recruiting Canadian
transvaginal ultrasound could be used as an indication
patients at risk for PTL to evaluate vaginal administration of
for prophylactic progesterone therapy. The therapy
should be started after 20 weeks’ gestation and stopped
Recommendations
when the risk of prematurity is low. (I-A)
1. Women at risk for PTL should be encouraged to partici-
4. On the basis of the data from the RCTs and meta-
pate in studies on the role of progesterone in reducing
analysis, it is recommended that in cases where the clini-
cian and the patient have opted for the use of progester-
2. Women should be informed about the lack of available
one the following dosages should be used:
data for many neonatal outcome variables and about the
• For prevention of PTL in women with history of
lack of comparative data on dosing and route of adminis-
previous PTL: 17 alpha-hydroxyprogesterone
tration. Women with short cervix should be informed of
250 mg IM weekly (I-B) or progesterone 100 mg
the single large RCT showing the benefit of progesterone
• For prevention of PTL in women with short cervix
3. Women and their caregivers should be aware that a
of < 15 mm detected on transvaginal ultrasound at
previous spontaneous preterm labour and/or short
22–26 weeks: progesterone 200 mg daily vaginally. (I-A)
l JANUARY JOGC JANVIER 2008
The Use of Progesterone for Prevention of Preterm Birth
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JANUARY JOGC JANVIER 2008 l
Recent Technological Advances In Flexible Electronics RECENT TECHNOLOGICAL ADVANCES IN FLEXIBLE ELECTRONICS 1AKSHAT JARIWALA, 2SHIJIN RAMESH Department of Electronics and Telecommunication engineering, Rajiv Gandhi Institute of Technology, India Department of Electronics and Telecommunication engineering, Rajiv Gandhi Institute of Technology, India Abstract : Flexible electronics