placental alpha microglobulin-1 detection in cervico ... · placental alpha microglobulin-1...
TRANSCRIPT
European International Journal of Science and Technology Vol. 4 No. 5 June, 2015
21
Placental Alpha Microglobulin-1 Detection in Cervico-vaginal Secretions in
the Diagnosis of Preterm Premature Rupture of The Membranes
Mouhamed Roshdy Mahmoud1, Foad Abd El Kader Abo Hamela
1, Mariem Mahmoud Mouhamed
1
and Medhat Mounir Kamel2*
1 Department of Obstetrics and Gynecology, Faculty of Medicine, Cairo University, Cairo, Egypt; 2 National
Research Center, Cairo, Egypt
* Corresponding author:
Medhat Mounir Kamel, M.B.B.CH.
Research fellow, National Research Center,
Cairo, Egypt
Email: [email protected]
Abstract
Objective: This study aimed to evaluate the value of detection of placental alpha macroglobulin-1 (PAMG-1)
in cervicovaginal discharge as a diagnostic test for Premature Rupture of Membranes (PROM) compared
with traditional methods.
Methods: A comparative study was conducted on 60 pregnant women 20-37 weeks of gestation in Cairo
University Maternity Hospital, Egypt. PROM was evaluated using U/S, Ferning test, Nitrazine test, pooling,
and PAMG-1 immunoassay. The studied women were divided into two groups based on the presence or
absence of PROM. Confirmed diagnosis of PROM was based an artificial gold standard. Sensitivity,
specificity, positive and negative predictive values and overall accuracy of the diagnostic tests were
calculated.
Results: PAMG-1 was superior to other tests regarding sensitivity (96%), specificity (97.14%), positive
predictive value (96%), negative predictive value (97.14%) and accuracy (96.67%).
Conclusion: PAMG-1 has a higher accuracy than the traditional methods, with high sensitivity and specificity
and is easy to use.
Key words: Placental alpha macroglobulin-1;cervico-vaginal secretions; premature rupture of membranes
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
22
1. Introduction
Membrane rupture is one of the most common disorders during pregnancy. It may occur at any time
in the pregnancy. It may happen appropriately with the onset of labor at term, or prematurely, prior to the
onset of labor. When occurring prior to the onset of labor for more than 24 hours at term, it is referred to as
premature rupture of membranes or PROM. Alternatively, it may occur in a preterm gestation, less than 37
weeks and is referred to as preterm premature rupture of membranes or PPROM ( Deering, et al., 2007).
Regardless of when membrane rupture takes place, the method of diagnosis is the same.
PROM occurs in approximately 10% of all pregnancies after 37 weeks gestation and in 2-3.5% of
pregnancies before 37 weeks gestation. PROM constitutes a major etiological factor of prenatal and
postnatal complications. It is a significant cause of premature delivery and other maternal and neonatal
complications (Simhan, et al., 2005).
The management of a patient with PROM and PPROM is expensive and difficult as the clinician
attempts to balance the risk of prolonging pregnancy against the risks of acquiring intrauterine and maternal
infection and the immaturity of lung development. Therefore, correct and timely diagnosis of this disorder is
critical (Hofmeyr, et al., 2014).
Membrane rupture, either PROM or PPROM, can be conducted when the following
symptoms/conditions occur: i) Vaginal secretions increase or become watery, especially in women at the risk
of preterm delivery or after an insult to the abdomen, as a fall, strike or shake of the stomach, leading to
potential rupture of fetal membranes.ii) Visible or unnoticed leakage of amniotic fluid (Caughey, et al.,
2008). .
Evaluation of the patient begins with full history taking, full general and local examination. Then a
sterile speculum examination is done, from which three signs of membrane rupture are sought; pooling,
positive Ferning test,and positive Nitrazine test. Additionally, oligohydramnios (low amnioticfluid level)
may be detected by sonographic examination suggestive of amniotic fluid loss secondary to membrane
rupture but not conclusive (Medina & Hill, 2006).
In diagnosing PROM, the history and physical examination alone often are inadequate to confirm the
status of the membranes. Fluid may not be present in the vagina for evaluation; the fluid may be
contaminated with urine, cervical mucus, vaginal discharge, blood, or meconium. Because of these
difficulties, multiple cytological, biochemical, colorimetric and sonographic methods have been developed
for detection of ruptured membranes. Despite significant advances in technology, no one test has been
found to be completely accurate, and the diagnosis still requires an integration of historic factors, physical
examination, and laboratory testing (Caughey, et al., 2008).
Noting that pooling strongly supports the diagnosis of Rupture of Membranes (ROM)(Alexander, et
al., 2000).However, this finding is not always present in a patient with ROM(Wiberg-Itzel, et al., 2005).
Amniotic fluid produces a delicate ferning pattern, in contrast to the thick and wide arborization pattern of
dried cervical mucus. However, the method of “Ferning” has been associated with false positive results
described secondary to contamination with fingerprints on a slide or contamination with semen and cervical
mucus. False negatives may be caused by inadequate amniotic fluid on swabs or contamination with
blood(Mercer & Lewis, 1997). The strength of the fern test to differentiate between amniotic and non-
amniotic fluid in vaginal discharge was investigated in the laboring and non-laboring patient with noted
differences in sensitivity and specificity. Sensitivity and specificity in the laboring group were 98.0% and
88.0%. In the non-laboring group, sensitivity and specificity were only 51.4% and 70.8%, respectively(De
Haan, et al., 1994).
The Nitrazine test is designed only to confirm an alkaline pH in the cervico-vaginal secretion, the pH
of the vaginal secretions is generally 4.5-6.0 whereas amniotic fluid usually has a pH of 7.1-7.3. Yet it is the
European International Journal of Science and Technology Vol. 4 No. 5 June, 2015
23
most common test used to diagnose PROM, it is associated with false-positive results ranging from 1% to
17% that can result from alkaline urine, blood, semen, vaginal discharge in cases of bacterial vaginosis, or
Trichomonas infection. Sensitivity and specificity have been reported at 90.7% and 77.2% respectively
(Cousins, et al., 2005; ACOG, 2007).
Membrane rupture is suspected to have occurred if any of the above three findings are present and
diagnosis is confirmed when all three findings are noted. However, all three findings are not mandatory for
the diagnosis of membrane rupture. When two of three are present, clinical correlation is exercised.
Frequently, equivocal results are obtained when diagnostic criteria are not met and result in false positive
and false negative diagnosis of ruptured membranes (Medina & Hill, 2006).
There are many biochemical tests, which have been studied for the diagnosis of ROM.A good test
must be reliable, simple and rapid(Esim, et al., 2002).These biochemical markers include prolactin (Shahin
& Raslan, 2007; Kariman, et al., 2012), alpha-feto-protein (AFP)(Shahin & Raslan, 2007),fetal fibronectin
(Lockwood, et al., 1991), diamine-oxidase, insulin-like growth factor binding protein-1 (IGFBP-
1)(Lockwood, et al., 1994; Gaucherand, et al., 1997),beta-subunit of human gonadotropin (B-HCG) (Esim,
et al., 2003; Shahin & Raslan, 2007)and urea-creatinine(Osman & Elghazaly, 2014).However, prolactin
and AFP were not useful markers for PROM because of the overlap in concentrations between pregnant
women with and without ruptured membranes(Phocas, et al.,1989).Moreover, chorionic release of fetal
fibronectin preceding delivery in patients with intact membranes may also lead to false-positive results.
IGFBP-1 is a major protein of amniotic fluid, which can be detected by a dipstick method in 5 minutes
(Erdemoglu & Mongan, 2004).
When the diagnosis remains unclear, an invasive method may be applied where amniocentesis is
done and a dye (Evans Blue or Fluorescein) is injected and leakage from the cervix is visualized. This
method is highly invasive and has many complications and can itself induce a PROM and miscarriage.
Therefore, a rapid, accurate, inexpensive, and noninvasive test for the diagnosis of PROM is urgently needed
(Caughey, et al., 2008).
The use of PAMG-1 detection in cervico-vaginal discharge as a simple, easy, rapid and minimally
invasive diagnostic test for PROM is getting popularity nowadays. It has high concentration in the amniotic
fluid, low level in blood and extremely low background level in cervico-vaginal secretions with intact fetal
membranes (Cousins, et al., 2005).
This study aimed to evaluate the detection of PAMG-1 in cervico-vaginal discharges as a diagnostic test for
ROM in comparison with traditional tests.
2. Methodology
This comparative study was carried out in Cairo University Maternity Hospital, Cairo, Egypt from
October 2009 to March 2010. The study included 60 pregnant women between 20-37 weeks of gestations
who were divided into two groups based on the presence or absence of PROM. The study excluded pregnant
women who had active vaginal bleeding or infection, placenta previa, complicated pregnancy, fetal distress
or known fetal anomalies.
A written informed consent (in Arabic language) was obtained from all participants. It included all
details about the purpose of the study and the method of sample collection.
Full history taking, physical examination, sterile speculum examination and transabdominal
ultrasound examination were performed. All participants were assessed using Amniotic Fluid Index (AFI),
pooling test, Nitrazine test, Ferning test and PAMG-1 rapid immunoassay test (AmniSure).
AFI was calculated by 4 quadrants method during the ultrasound examination. This consists of the
sum of the vertical diameters of the largest pockets seen in each of the four quadrants of the uterus. The AFI
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
24
is considered normal between 8.1 and 18 cm, low between 5.1 and 8.0 cm, very low <5 cm, and high >18
cm. for optimum accuracy, the mean of three AFI measurements was calculated, when the AFI is <10
cm(Nabhan & Abdelmoula, 2008).
The Nitrazine test was carried out by swapping the posterior vaginal fornix with a Litmus paper. A
positive result was interpreted as a change of the Litmus paper colour into dark blue indicating alkaline pH
of the amniotic fluid.
For doing the Ferning test, a drop of vaginal secretion from the posterior fornix was collected by a
sterile syringe and put on a dry clean glass slide. Then waiting for 3 minutes to dry and microscopic
examination was done. A positive fern test is defined as visualization of arborization(the tree like pattern) is
observed(ACOG, 2007).
Detection the presence of PAMG-1 in cervicovaginal discharge was carried out using the Amnisure
kits(Lee, et al., 2007). Rapid immunoassay of PAMG-1 was performed by placing a sterile swab at the
posterior vaginal fornix for about one minute. It was then rinsed into a vial containing solvent for another 1
minute and then disposed. The test strip was inserted in the solvent, and the result would be available in 5
minutes. The test was considered negative If only a control line is visible. While if both control and test
lineswere visible, the test result was positive. If no lines were visible, the test result was invalid(Joong&
Errol, 2005).
Blood samples were collected from participants to do CBC for TLC, ESR and CRP.
2.1. Statistical analysis
For the diagnosis of ROM, an artificial gold standard was used. This included the sum of the results of
Nitrazine, Ferning, and pooling tests. If two or more out of three were positive, the patient was considered to
have a confirmed ROM. If less than two were positive in spite of the positive history of gush of fluid
vaginally, this patient was considered not to have ROM; if less than two were positive and the patient had
no history of leakage this patient was included in the control group (Cousins, et al., 2005).
The collected data were described in terms of mean ±Standard Deviation (± SD), range, frequencies
and percentages as appropriate. Comparisons between the study groups were carried out using the
independent Student t-test for quantitative data when normally distributed. The test of proportion (Z-test)
was used to compare the proportions of women who had trauma or coitus before the onset of vaginal leak
and those who did not. The Chi square (χ2) test and Fisher’s Exact Test (FET) were used to compare more
than two proportions as appropriate. Accuracy was represented using the terms sensitivity, specificity,
positive predictive value, negative predictive value and overall accuracy. A probability value (p-value) less
than 0.05 was considered statistically significant. All statistical calculations were done using computer
programs Microsoft Excel 2003 (Microsoft Corporation, NY, USA) and SPSS (Statistical Package for the
Social Science; SPSS Inc., Chicago, IL, USA) version 15 for Microsoft Windows.
3. Results
A total of 60 pregnant women were evaluated for PROM according to the artificial golden role
discussed before. Of these, 25 (41.7%) were positive for PROM and 35 (58.3%) were negative for PROM.
Table 1 shows differences between the positive and negative groups for PROM regarding some clinical
characteristics. Parity was higher among women who were positive for PROM than those who were negative
(P=0.02). There were no significant differences as regard age, duration of marriage, gestational age,
gravidity, abortion and history of ROM in previous pregnancies.
There were no significant differences between patient with positive PROM and those with negative
PROM as regard to markers of infection (Table 2).
European International Journal of Scien
There were no significant differ
leaking (n=30) and had history of trauma
positive for PROM (n=25) and those wh
Figure 1 Comparison between the st
within 48 hrs. and trauma before leak
The number of patients who
examination and oligohydraminos on U
compared to those who were negativ
significant at P<0.001.Similarly, PAMG
(P<0.001). AFI was higher among co
difference in between (7±3.14 vs. 13.6±4
Table 4 shows that PAMG-1 was
positive and negative predictive value a
and specificity (97.14%) compared t
sensitivity(88%). While AFI detection b
PAMG-1 in cervicovaginal discharge w
value, negative predictive value and ac
had less negative predictive value (92%
96.67%respectively).
0
5
10
15
20
25
30
35
40
45
Trauma before leaking
20
0
%
Positive PRO
ence and Technology Vol. 4 No. 5
ferences in the proportions of pregnant women
ma before leaking or coitus within 48 hours betwe
ho were negative (n=5)(Figure 1).
studied women with leaking (n=30) as regar
king by the diagnosis of PROM
o had positive Nitrazine test, Ferning test, po
U/S examination was higher among women w
tive PROM (Table 3). These differences were
G-1 was more likely detected among PROM p
control group compared to PROM group wit
±4.17; P<0.001).
as superior to other diagnostic tests as regard to se
e and accuracy collectively.PAMG-1 had both hi
to other tests. Pooling had specificity of 1
n by U/S had specificity of 91.3% but low sensi
was superior to other diagnostic tests as regard t
accuracy. Although pooling had positive predicti
2%)and less accuracy (95%) than PAMG-1 det
ing Coitus within 48 hrs
44
20
PROM Negative PROM
June, 2015
n who presented with
weenwomen who were
ard history of coitus
pooling on speculum
with positive PROM
re statistically highly
patients than controls
ith highly significant
sensitivity, specificity,
high sensitivity (96%)
100% but had low
nsitivity (64%). Again,
to positive predictive
ctive value of 100% it
detection (97.14% and
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
26
Table 1 Clinical characteristics of the studied groups
Characteristics
Positive PROM group
(n = 25)
Negative PROM group
(n = 35) Test
statistics P
Mean±SD Range Mean±SD Range
Maternal age
(years) 29.44±6.28 19-41
30.80
±7.26 18-44 t= 0.75 0.45
Duration of marriage
(years)
6.52
±4.75 1-19
7.23
±5.28 1-20 t=0.53 0.59
Calculated gestational age
(weeks)
32.80
±2.33 29-36
33.71
±2.55 31-36 t=1.41 0.16
Gravidity 2.88
±1.86 1-5
3.09
±1.77 2-5 t=0.44 0.66
Parity 1.80
±1.08 0-4
1.11
±1.13 0-4 t=2.37 0.02
Abortion 0.80
±1.80 0-3
0.97
±1.20 1-2 t=0.44 0.66
History of ROM in previous
pregnancy (n=39)
No (%)
Yes (%)
12 (70.59)
5 (29.41)
14 (63.64)
8 (36.36)
χ2 = 0.209
0.65
Table 2 Results of CBC, ESR and CRP In the studied groups
*Obtained using the Fisher’s Exact Test
Variable
Positive PROM group
(n = 25)
Negative PROM group
(n = 35) P*
No. % No. %
CBC (leukocytosis) Yes
No
3
22
12.00
88.00
3
32
8.57
91.43 0.69
ESR Yes
No
4
21
16.00
84.00
2
33
5.71
94.29 0.22
CRP Yes
No
5
20
20
80
3
32
8.57
91.43 0.26
European International Journal of Science and Technology Vol. 4 No. 5 June, 2015
27
Table 3 Results of Nitrazine test, Fernning test, pooling test, PAMG-1 immunoassay, oligohydraminos
and AFI by the diagnosis of PROM in the studied groups
Test
Positive PROM
group
(n = 25)
Negative PROM
group
(n = 35)
Test
statistic P
No. % No. %
Nitrazine test Positive
Negative
23
2
92.00
8.00
5
30
14.29
85.71 χ
2=35.39 <0.001
Ferning test Positive
Negative
23
2
92.00
8.00
5
30
14.29
85.71 χ
2=35.39 <0.001
Pooling test Positive
Negative
22
3
88.00
12.00
0
35
0.00
100.00 χ
2=48.63 <0.001
PAMG-1 Positive
Negative
24
1
96.00
4.00
1
34
2.86
97.14 χ
2=52.05 <0.001
Oligohydraminos Yes
No
16
9
64.00
36.00
3
32
8.57
91.43 χ
2=20.70 <0.001
AFI (cm) Mean± SD;
(range) 7±3.14; (3-15) 13.6±4.17; (6-25) t=6.67 <0.001
Table 4 Comparison between the studied groups as regard the results of PAMG-1, Nitrazine test,
Ferning test, pooling test and AFI.
Test Sensitivity
(%)
Specificity
(%)
Positive
predictive
value (%)
Negative
predictive
value (%)
Accuracy
(%)
PAMG-1 96.00 97.14 96.00 97.14 96.67
Nitrazine test 92.00 85.71 82.14 93.75 88.33
Ferning test 92.00 85.71 82.14 93.75 88.33
Pooling test 88.00 100.00 100.00 92.11 95.00
AFI (cm) 64.00 91.30 84.21 78.04 80.00
4. Discussion
PROM is a condition, which occurs in pregnancy when the amniotic sac ruptures before the onset of
labor. PPROM is a condition where the amniotic sac leaks fluid before 37 weeks of gestation(Deering et al.,
2007).Correct diagnosis of PROM has great importance because failure of diagnosis can lead to unwanted
obstetric complications like chorioamnionitis. On the other hand over diagnosis can lead to unnecessary
interventions like hospitalization and preterm birth (Kim, et al., 2005).
Diagnosis of PROM is easy when the rupture is obvious but difficult and indeed impossible when the
leaking is minimal. Therefore, there is a growing need to discover a reliable, simple and rapid biochemical test
for the diagnosis of ROM (Esim et al., 2002).A number of biochemical markers for the diagnosis of ROM have
been studied. However, none of them was proved to be a gold standard marker for routine diagnosis, so it
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
28
was necessary to discover a new marker for the diagnosis of PROM.
PAMG-1protein was isolated from amniotic fluid in 1975. It can be measured in amniotic fluid using
immunochemical methods.PAMG-1 was selected as a marker of fetal membrane rupture due to its
unique characteristics; high concentration in the amniotic fluid, low level in blood, and extremely low
background level in cervicovaginal secretions with intact fetal membranes(Cousins, et al., 2005).
Furthermore, small quantities of amniotic fluid in vaginal secretions could be detected by the use of a
combination of monoclonal antibodies. By setting its sensitivity threshold at 5 ng/ml, detection of PAMG-1
minimizes the probability of false-positive and false-negative results. In addition, the increased levels of
PAMG-1 in the vaginal secretions is highly predictive of ROM (Mulhair, et al., 2009).
In this study,PAMG-1 detection in cervicovaginal discharge by AmniSure was compared to an artificial
gold standard for diagnosis of ROM. The latter included the sum of results of Nitrazine, Ferning, and
Pooling tests.
The results of this study revealed that the sensitivity, specificity, positive predictive value, negative
predictive value and accuracy of Nitrazine test were 92%, 85.71%, 82.14%, 93.75%, and 88.33% respectively.
These results are in line with those mentioned in the study by Gaucherand, et al. (1997) who reported a
sensitivity and specificity of 90.7%and 77.2%respectively. They stated that Nitrazine evaluation was
associated with false-positive results up to 17.4% secondary to cervicitis, vaginitis (bacterial vaginosis or
trichomonas), alkaline urine, blood, semen, and antiseptics. A significant false negative rate (12.9%) for
Nitrazine test was observed.
As regards Ferning, the results of the present study detected that the sensitivity, specificity, positive
predictive value, negative predictive value and accuracy were 92%, 85.71%, 82.14%, 93.75%, and 88.33%
respectively. These corresponds to Rosemond, et al. (1990) who mentioned that Ferning has been associated
with false-positive results in 5 to 30% of patients; the result was described secondary to contamination with
fingerprints on the slide or contamination with semen and cervical mucus. False-negative results (5 to
12.9%) might be caused by dry swabs, contamination with blood and heavy discharge. In the non-laboring
group, sensitivity and specificity were 51.4% and 70.8%, respectively (De Haan, et al., 1994).
As for pooling, the results of the present study detected that the sensitivity, specificity, positive predictive
value, negative predictive value and accuracy were 88%, 100%, 100%, 92.11 and 95% respectively.
Indeed Lee et al. (2007) stated that the traditional diagnostic methods using nitrazine/pH, assessment
of pooling, and microscopic ferning testing lack reliability and become progressively less accurate with
passage of time since membrane rupture. Thus in cases of prolonged PROM, these tests provide no better
diagnostic information than that obtained by simple clinical examination.
In this study, AFI was proved to be significantly lower in the group positive for ROM. These findings
confirm the results of the study done by Frigo et al. (1998) who suggested that U/S examination was an
important tool for the diagnosis of PROM. On the other hand, Kafali and Oksuzler (2007) concluded that there
was no significant statistical difference between women with confirmed diagnosis of PROM, as indicated by
positive Nitrazine and pooling tests, those with suspected PROM and controls regarding AFI. However, amongst
the studied tests, AFI showed the least sensitivity (64%), positive predictive value (84%), negative predictive
value (78%) and accuracy (80%). These results are in contrast with those reported by Erdemoglu and Munganl
(2004) who found that the sensitivity, and accuracy of AFI were 94%, and 92% respectively.
The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of detection of
PAMG-1 in cervicovaginal discharge in detecting ROM were 96%, 97.14%, 96%, 97.14%, and 96.67%
respectively. These results are consistent with those reported by Cousins et al. (2005) who stated that the
AmniSure diagnostic test demonstrated a sensitivity of 98.9%, specificity of 100%, positive predictive value
of 100%, and a negative predictive value of 99.1%.
European International Journal of Science and Technology Vol. 4 No. 5 June, 2015
29
Lee et al. (2007) performed a prospective observational study in consecutive patients with signs or
symptoms of rupture membranes. Of a total 183 patients, 157 (87%) had rupture of membranes at their initial
presentations using the same gold standard employed in the present study.PAMG-1 immunoassay was proved to
have a sensitivity of 98.7%, specificity of 87.5%, positive predictive value of 98.1%, and negative predictive
value of 91.3%. A false-positive test (defined as a positive placental immunoassay in women who were
subsequently determined not to have ROM) was documented in three cases.
Chen and Dudenhausen (2008) compared two rapid strip tests for the detection of amniotic fluid,
based on the detection of insulin-like growth factor-binding protein-1 (IGFBP-1) and of PAMG-1. Samples
of amniotic fluid were taken from 20 pregnant women between 31 and 41 gestational weeks at elective
Cesarean section before delivery of the newborn. These samples were diluted with 0.9 % saline solution in a
dilution series down to the concentrations of 1:320. Comparison between the two tests was carried out to
evaluate their ability to detect different concentrations of amniotic fluid. The test based on PAMG-1 proved
to be superior in 15 cases by detecting amniotic fluid at least at one descending concentration below the test
based on IGFBP-1. Thus, it was concluded that the rapid strip test based on PAMG-1 is a more sensitive
bedside test compared with the test based on IGFBP-1 for the detection of amniotic fluid. Furthermore,
PAMG-1 immunoassay was recommended as a promising and noninvasive test for the diagnosis of
ROM(Caughey, et al., (2008);Duff, (2009)).
Lee et al. (2009) concluded that a positive Amnisure test is present in about one-third nulliparous women at
term presenting in labor with intact membranes; and patients with a positive Amnisure test had a shorter
admission-to-delivery interval than those with a negative test. This may imply restriction of the use of the
test in preterm patients. In fact, this is the group of patients expected to really benefit from such testing
where the decision making regarding active intervention may really make a difference.
To summarize, PAMG-1 detection in cervicovaginal discharges by the use of Amnisure test is a useful
method for the diagnosis of PROM as it was more accurate than the traditionally available tests, with high
sensitivity and specificity, and easy to use as mentioned previously .
References
1. Alexander, J. M., Mercer, B. M., Miodovnik, M., Thumau, G. R., Goldenberg, R. L., Das, A. F., et al.
(2000). The impact of digital cervical examination on expectantly managed preterm rupture of
membranes. Am J Obstet Gynecol., 183, 1003-1007.
2. American College of Obstetrician and Gynecologists (ACOG) Committee on Practice Bulletins–
Obstetrics, Authors. (2007). ACOG Practice Bulletin No. 80: premature rupture of membranes.
Clinical management guidelines for obstetrician-gynecologists. Obstet Gynecol., 109, 1007:1019.
3. Caughey, A. B., Robinson, J. N. and Norwitz, E. R. (2008). Contemporary diagnosis and
management of preterm premature rupture of membranes. Rev Obstet Gynecol., 1, 11-22.
4. Chen, F. C. and Dudenhausen, J. W. (2008). Comparison of two rapid strip tests based on IGFBP-1
and PAMG-1 for the detection of amniotic fluid. Am J Perinatol., 25, 243:246.
5. Cousins, L. M., Smok, D. P., Lovett, S. M. and Poeltler, D. M. (2005). AmniSure placental alpha
macroglobulin-1 rapid immunoassay versus standard diagnostic methods for detection of rupture of
membranes. Am J Perinatol., 22, 317-320.
6. De Haan, H. H., Offermans, P. M., Smits, F., Schouten, H. J. and Peeters, L. L. (1994). Value of the
fern test to confirm or reject the diagnosis of ruptured membranes is modest in nonlaboring women
presenting with nonspecific vaginal fluid loss. Am J Perinatol.,11, 46-50.
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
30
7. Deering, S. H., Patel, N., Spong, C. Y., Pezzullo, J. C. and Ghidini, A. (2007). Fetal growth after
preterm premature rupture of membranes: is it related to amniotic fluid Volume. J Matern Fetal
Neonatal Med., 20, 397-400.
8. Duff, P. (2009). Preterm premature rupture of membranes. UpToDate [online serial]. Waltham, MA:
UpToDate.
9. Erdemoglu, E. and Mungan, T. (2004). Significance of detecting insulin – like growth factor binding
protein-1 in cervicovaginal secretions: comparison with nitrazine test and amniotic fluid volume
assessment. Acta Obstet Gynecol Scand., 83, 622-626.
10. Esim, E., Turan, C., Unal, O., Dansuk, R. and Cengizlu, B. (2003). Diagnosis of premature rupture of
membranes by identification of beta-HCG in veginal washing fluid. Eur J Obstet Gynecol Reprod
Biol., 107, 37:40.
11. Frigo, P., Lang, C., Sator, M., et al. (1998). Membranes thickness and PROM- high frequency
ultrasound measurements. Prenatal Diagn., 18, 333-337.
12. Gaucherand, P., Salle, B., Sergeant, P., Guibaud, S., Brun, J., Bizollon, C. A., Rudigoz, R. C. (1997).
Comparative study of three vaginal markers of the premature rupture of membranes. Insulin like
growth factor binding protein 1, diamine-oxidase and pH. Acta Obstet Gynecol Scand., 76, 536-540.
13. Hofmeyr, G. J., Eke, A. C. and Lawrie, T. A. (2014). Amnioinfusion for third trimester preterm
premature rupture of membranes. Cochrane Database Syst Rev. Doi:
10.1002/14651858.CD000942.pub3.
14. Joong, S. and Errol, R. (2005). Technical innovations in clinical obstetrics., Contemporary OB/GYN
Special Technology Issue3, Vol. 50 ;203:214.
15. Kafali, H. and Oksuzler, C. (2007). Vaginal fluid urea and creatinine in diagnosis of premature
rupture of membranes. Arch. Gynecol. Obstet., 160, 157:205.
16. Kariman, N., Hedayati, M. and Majd, S. A. (2012). The Role of Vaginal Prolactin in Diagnosis of
Premature Rupture of Membranes. Iran Red Crescent Med J., 14, 352-357.
17. Kim, Y. H., Park, Y. W., Kwon, H. S. and Kim, B. J. (2005). Vaginal fluid beta-human chorionic
gonadotropin level in the diagnosis of premature rupture of membranes. Acta Obstet Gynecol Scand.,
84, 802-805.
18. Lee, S. E., Park, J. S., Norwitz, E. R., Kim, K. W., Park, H. S. and Jun, J. K. (2007). Measurement of
placental alpha-microglobulin-1 in cervicovaginal discharge to diagnose rupture of membranes. Obstet
Gynecol., 109, 634-640.
19. Lee, S. M., Lee, J., Seong, H. S., Lee, S. E., Park, J. S., Romero, R. and Yoon, B. H. (2009). The
clinical significance of a positive Amnisure test in women with term labor with intact membranes. J
Matern Fetal Neonatal Med., 22, 305-310.
20. Lockwood, C. J., Senyei, A. E., Dische, M. R., Casal, D., Shah, K. D., Thung, S.N., et al. (1991).
Fetal fibronectin in cervical and vaginal secretions defines a patient population at high risk for
preterm delivery. N Engl J Med., 325, 669-74.
21. Lockwood, C. J., Wein, R., Chien, D., Ghidini, A., Alvarez, M., Berkowitz, R. L. (1994). Fetal
membrane rupture is associated with the presence of insulin-like growth factor-binding protein-1 in
vaginal secretions. Am J Obstet Gynecol., 171, 146-150.
22. Medina, T. M. and Hill, D. A. (2006). Preterm premature rupture of membranes: Diagnosis and
management. Am Fam Physician., 73, 659-664.
23. Mercer, B. M. and Lewis, R. (1997). Preterm labor and preterm premature rupture of the membranes.
European International Journal of Science and Technology Vol. 4 No. 5 June, 2015
31
Diagnosis and management. Infect Dis Clin North Am., 11, 177:201.
24. Mulhair, L., Carter, J., Poston, L., Seed, P., Briley, A. (2009). Prospective cohort study investigating
the reliability of the AmnioSense method for detection of spontaneous rupture of membranes.
BJOG., 116, 313-318.
25. Nabhan, A. F. and Abdelmoula, Y. A. (2008). Amniotic fluid index versus single deepest vertical
pocket as a screening test for preventing adverse pregnancy outcome. Cochrane Database Syst Rev.
16(3): CD006593. doi: 10.1002/14651858.CD006593.pub2.
26. Osman, O. and Elghazaly, M. (2014). Can Vaginal Washing Fluid Urea, Creatinine and Qualitative β-
hCG Diagnose Suspected Premature Rupture of Membranes? Open Journal of Obstetrics and
Gynecology, 4, 967-972.
27. Phocas, I., Sarandakou, A., Kontoravdis, A., Chryssicopoulos, A., Zourlas, P. A. (1989). Vaginal fluid
prolactin: a reliable marker for the diagnosis of prematurely ruptured membranes. Comparison with
vaginal fluid alphafetoprotein and placental lactogen. Eur J Obstet Gynecol Reprod Biol., 31, 133-
141.
28. Rosemond, R. L., Lombardi, S. J. and Boehm, F. H. (1990). Ferning of amniotic fluid contaminated
with blood. Obstet Gynecol., 75, 338–340.
29. Shahin, M. and Raslan, H. (2007).Comparative Study of Three Amniotic Fluid Markers in Premature
Rupture of Membranes: Prolactin, Beta Subunit of Human Chorionic Gonadotropin, and Alpha-
Fetoprotein. Gynecol Obstet Invest., 63, 195-199.
30. Simhan, H. N., Caritis, S. N., Krohn, M. A. and Hillier, S. L. (2005). The vaginal inflammatory
milieu and the risk of early premature preterm rupture of membranes. Am J Obstet Gynecol., 192,
213-218.
31. Wiberg-Itzel, E., Cnattinqius, S. and Nordstrom, L. (2005). Lactate determination in vaginal fluids: a
new method in the diagnosis of prelabor rupture of membranes. BJOG., 112, 754-758.