Maternal serum creatine kinase: a possible predictor of tubal pregnancy

Role of creatine phosphokinase as a diagnostic marker in tubal ectopic pregnancy

Background and Aim

Ectopic pregnancy (EP) is still one of the leading preventable causes of maternal morbidity and mortality in the first trimester. Amidst the use of sensitive assays for β-HCG and high-definition ultrasonography for the identification of EP, the search for a more reliable and sensitive marker remains a challenge till date. Our aim was to determine the validity of creatine phosphokinase (CPK) and its isoenzyme (CPK-MB) in the prediction of tubal EP.

Materials and Methods

A prospective and comparative diagnostic accuracy study was conducted among 105 pregnant women in the first trimester who met the eligibility criteria in the Department of Obstetrics and Gynecology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences (NEIGRIHMS). The study included 35 patients each with tubal EP (EP), abortive intrauterine pregnancy (AP), and normal intrauterine pregnancy (NP). CPK, CPK-MB, and β-HCG were measured among all the participants, and the participants were followed up longitudinally.

Results

A total of 105 pregnant women were included. The mean CPK and CPK-MB levels were significantly higher among the women with EP when compared to NP (P < 0.05) and AP (P < 0.05) women; however, there was no significant difference between the NP and AP groups (P > 0.05). Moreover, the receiver operating characteristic (ROC) curve showed that both CPK and CPK-MB were good predictors of EP, with CPK (area under the curve [AUC] = 0.764) being a better predictor than CPK-MB (AUC: 0.650) in the diagnosis of EP.

Conclusion

Early diagnosis of EP allows appropriate and timely management, which would not only reduce mortality and morbidity associated with the condition but also enable preservation of fertility and improve future pregnancy outcome. Hence, the need of the hour is a reliable biochemical diagnostic marker for EP, such as CPK.

Using dynein heavy chain 5 and creatine kinase levels in cervical fluid and blood for early diagnosing of ectopic pregnancy

AIM

Ectopic pregnancy is a life-threatening problem in reproductive ages. Diagnosing ectopic pregnancy in the early period provides to reducing mortality and morbidity and gives an opportunity for medical treatment to preserve fallopian tubes. Evaluation of cervical fluid for determining ectopic pregnancy with new promising markers provided different aspects for diagnosing ectopic pregnancy in the present study.

METHODS

In this prospective clinical study, ectopic pregnant patients as ectopic pregnancy group (n = 46), intrauterine pregnant patients as intrauterine pregnancy group (n = 29) and not-pregnant patients as nonpregnancy group (n = 10) participated to study. Cervical fluid samples were collected with using merocel sponge. In addition, serum samples were obtained from patients. Dynein heavy chain 5 (DNAH5) and creatine kinase (CK) levels were determined by enzyme-linked immunosorbent assay kits in samples.

RESULTS

Reduced cervical fluid DNAH5 levels was diagnosed in ectopic pregnancy group compared to intrauterine pregnancy group (median 3.42 ng/mL; 25-75% percentile 0-9.56 ng/mL vs median 6.14 ng/mL; 1.40-8.31 ng/mL; P < 0.001). On the other hand, DNAH5 protein was not detected in nonpregnant patients' samples. In addition, statistical significant increased cervical fluid CK levels were diagnosed in ectopic pregnancy group compared to intrauterine pregnancy group (median 4477.61 IU/L; 0-64 925.37 IU/L vs 0 IU/L; 0-6832.30 IU/L; P = 0.006).

CONCLUSION

Measuring of CK and DNAH5 in cervical fluid could be promising markers for early diagnosing of ectopic pregnancy. Decreased DNAH5 levels in cervical fluid might be result from abnormal cilia function in ectopic pregnant patients. ClinicalTrials.gov ID. NCT02995356.

Molecular diagnostics and therapeutics for ectopic pregnancy

Ectopic pregnancies are a serious gynaecological emergency that can be fatal. As such, prompt diagnosis and safe timely treatment is essential. Here, we review the literature on the development of molecularly targeted diagnostics and therapeutics for ectopic pregnancy. A blood-based biomarker that accurately identifies an ectopic pregnancy could be used to offer early diagnostic certainty in cases where ultrasound cannot determine the location of the embryo ('a pregnancy of unknown location'). Molecules examined so far can be broadly grouped into biological themes of relevance to reproduction: (i) Fallopian tube (dys)function, (ii) embryo/trophoblast growth, (iii) corpus luteum function, (iv) inflammation, (v) uterine function and (vi) angiogenesis. While a sensitive and specific biomarker for ectopic pregnancy has yet to be identified, it is possible that improvements in platform technologies or a multi-modal biomarker approach may yield an accurate diagnostic biomarker test. Furthermore, with the advent of better imaging technology, the need for a blood-based biomarker test may be superseded by improvements in ultrasound or magnetic resonance imaging technology. There have been some recent preclinical studies describing molecularly targeted therapeutic approaches for ectopic pregnancy. Notably, bench-to-bedside studies have examined the use of combination gefitinib (orally available epidermal growth factor receptor inhibitor) and methotrexate. Preclinical studies suggest that combination gefitinib and methotrexate is highly effective in inducing placental cell death, and is significantly more effective than methotrexate alone. In early human trials, encouraging preliminary efficacy data have shown that combination gefitinib and methotrexate can rapidly resolve tubal ectopic pregnancies, and large extra-tubal ectopic pregnancies. If a large clinical randomized controlled trial confirms these findings, combination gefitinib and methotrexate could become a new medical treatment option for ectopic pregnancy.

Biomarkers for ectopic pregnancy and pregnancy of unknown location

Early pregnancy failure is the most common complication of pregnancy, and 1% to 2% of all pregnancies will be ectopic. As one of the leading causes of maternal morbidity and mortality, diagnosing ectopic pregnancy and determining the fate of a pregnancy of unknown location are of great clinical concern. Several serum and plasma biomarkers for ectopic pregnancy have been investigated independently and in combination. The following is a review of the state of biomarker discovery and development for ectopic pregnancy and pregnancy of unknown location.

Peritoneal relative to venous serum biomarker concentrations for diagnosis of ectopic pregnancy

PURPOSE

To retrospectively analyze the relationships of peritoneal serum relative to venous serum (R (p/v)) ratios for human chorionic gonadotropin, CA-125, and creatine kinase to the ectopic pregnancy (EP).

METHODS

Intra-abdominal fluid and venous blood samples of 118 subjects with suspected EP were obtained for biomarker measurements. R (p/v-hCG) >1 was considered indicative of EP, and final diagnosis was based on surgical finding of an ectopic chorionic villous or gynecological ultrasound finding of an intrauterine gestational sac.

RESULTS

R (p/v-hCG) and R (p/v-CA-125) were both significantly greater for abortive as compared to ruptured EP and for the absence as compared to presence of active bleeding. However, neither ratio differed significantly between ampullary and isthmic EP. R (p/v-hCG) and R (p/v-CA-125) correlated negatively with hemoperitoneum volume. R (p/v-hCG) exhibited only modest predictive value for rupture. However, with R (p/v-CA-125) as the diagnostic criterion for rupture, sensitivity and specificity were 66.7 and 100%, respectively; in patients initially diagnosed with EP, R (p/v-CA-125) values <22.43 effectively predicted rupture. R (p/v-CK) did not exhibit significant diagnostic value.

CONCLUSIONS

R (p/v-hCG) values >1 combined with positive culdocentesis test findings reliably indicate the presence of EP. In patients initially diagnosed with EP, R (p/v-CA-125) values <22.43 predict tubal rupture.

Serum biomarkers of tubal ectopic pregnancy: current candidates and future possibilities

Ectopic pregnancy remains a considerable cause of maternal morbidity and mortality worldwide. Currently, it is diagnosed using a combination of transvaginal ultrasound and serial serum beta-human chorionic gonadotrophin levels. Diagnosis is often delayed and these tests are time-consuming and costly, both psychologically to the patient and financially to health services. The development of a biomarker that can differentiate a tubal ectopic from an intrauterine implantation is therefore important. In the pre-genomic era, a one-by-one scientific approach has revealed over 20 candidate biomarkers that could be used as a test to diagnose ectopic pregnancy although at present their clinical utility is very limited. These biomarkers cluster into themes: markers of abnormal embryo/trophoblast growth, markers of abnormal corpus luteum function, markers of a growing pregnancy in the Fallopian tube, markers of inflammation and peritoneal irritation, and uterine markers of normal implantation. It is likely that this thematic approach will facilitate the identification of newer biomarkers using microarray technology and inform the development of investigative paradigms using multiple markers at the time of presentation.

Predicting Outcomes in Pregnancies of Unknown Location

A pregnancy of unknown location (PUL) is a descriptive term used to classify a woman when she has a positive pregnancy test but no intra- or extra-uterine pregnancy is visualized on transvaginal sonography. Expectant management has been shown to be safe for the majority of women with a PUL. Serum progesterone and human chorionic gonadotrophin levels as well as mathematical models play a role in predicting the final outcomes of PULs, which include intrauterine pregnancy, failing PUL and ectopic pregnancy. Other possible predictors of outcome have been studied, but currently no factor has been identified that combines accuracy with reproducibility and simplicity. This article discusses the various aspects of the management of women with PULs. Future work should be aimed at prospectively testing current models in order to predict the outcome of a PUL and minimizing follow-up.

Creatine phosphokinase in ectopic pregnancy revisited: significant diagnostic value of its MB and MM isoenzyme fractions

OBJECTIVE

Although evidence on elevated creatine phosphokinase (CPK) as a tool for the diagnosis of ectopic pregnancy (EP) is rather conflictive, no previous study on CPK isoenzyme levels and their relative ratio was found in the literature.

STUDY DESIGN

Forty women with EP, 20 with intrauterine (IU) abortive gestation, and 20 regular pregnant women (controls) were studied. Serum total CPK, CPK-MB, and CPK-MM levels were measured at the time of presentation and 24 hours after surgery. Relative operating characteristic (ROC) curves were plotted.

RESULTS

Women with EP had significantly higher CPK concentrations and a significantly decreased CPK-MB relative ratio (CPK-MB%), compared with both women with IU abortive pregnancy and controls. The ROC curves demonstrated a significant discriminatory ability of both increased total CPK and decreased CPK-MB% ratio for the diagnosis of EP.

CONCLUSION

Determination of CPK isoenzyme fractions can significantly enhance the diagnostic value of total maternal CPK in the prediction of ectopic pregnancy.

Ectopic pregnancy

Ectopic pregnancy is an important cause of morbidity and mortality worldwide. Use of transvaginal ultrasonography and quantitative measurement of the beta subunit of human chorionic gonadotropin (beta-hCG) has led to a reduction in the need for diagnostic laparoscopy. Furthermore, with earlier diagnosis, medical therapy with methotrexate can be offered and surgery avoided in some women, though the best regimen remains unclear. In the surgical management of ectopic pregnancy, the benefits of salpingectomy over salpingostomy are uncertain. Although there have been advances in the management of ectopic pregnancy there are still questions to be answered.

Do levels of serum cancer antigen 125 and creatine kinase predict the outcome in pregnancies of unknown location?

BACKGROUND

The aim of this study was to evaluate the role of maternal serum cancer antigen 125 (CA 125) and creatine kinase (CK) levels in predicting the outcome of pregnancies of unknown location (PUL).

METHODS

Prospective observational study. Women classified as PUL were recruited. Final outcome of each PUL was established: failing PUL, intrauterine pregnancy (IUP), ectopic pregnancy (EP) or persisting PUL. The persisting PUL group almost certainly represent ultrasonically missed EP and were included in EP group. Serum CK and CA 125 were measured at 0 and 48 h. The values at presentation and the change in levels after 2 days were used in the analysis. We incorporated the most significant of variables into a multinomial logistic regression model to predict all outcomes. The performance of this model was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

In all, 4698 consecutive women were scanned; 403 were classified as PUL, 27 were lost to follow-up. Of the 376 women eligible, 297 had complete data and therefore were recruited. Mean age and mean gestation were 30.0 years and 43.3 days respectively. Final outcomes: 153 failing PUL (51.5%), 116 IUP (39.1%) and 28 EP (9.4%). Mean serum CK levels at 0 and 48 h were 88.5 and 86.8 IU/l respectively. Mean serum CA 125 levels at 0 and 48 h were 43.8 and 40.1 kIU/l respectively. 81.1% of women had CK and CA 125 ratios (CK 48 h/CK 0 h, CA 125 48 h/CA125 0 h) between 0.7 and 1.3. CA 125 ratio was the only significant variable in the three outcome groups (P < 0.0001). Logistic regression analysis incorporating CA 125 ratio gave an area under ROC curve of 0.782 (SE = 0.041) for failing PUL, 0.768 (SE = 0.043) for IUP and 0.560 (SE = 0.078) for EP. This model was capable of distinguishing failing PUL from IUP, but was not able to detect EP.

CONCLUSIONS

Absolute levels of serum CK and CA 125 at the defined times cannot be used to predict the outcome of PUL. Although the CA 125 ratio when incorporated into logistic regression model can distinguish failing PUL from IUP, its inability to detect the high risk PUL, i.e. the developing EP, renders it inappropriate for use in the clinical setting.

Ectopic pregnancy: an update

PURPOSE OF REVIEW

This review discusses recent publications that investigate the epidemiology, diagnosis and treatment of ectopic pregnancy.

RECENT FINDINGS

Transvaginal ultrasound is being used with increasing confidence for the diagnosis of ectopic pregnancy, and methotrexate now has an established role in the treatment of ectopic pregnancy. No serum markers have been found that can reliably differentiate intrauterine from extrauterine pregnancy. As more experience has been gained with medical therapy, it is apparent that it is possible to identify a subgroup of women in whom it is unlikely to succeed. The use of adjunctive therapy such as mifepristone does not appear to increase the effectiveness of methotrexate. Screening for ectopic pregnancy in at-risk women has been suggested, but it may be of only limited value. In the surgical management of ectopic pregnancy the effect on fertility of salpingotomy and salpingectomy remains uncertain, although recent cohort studies suggest that salpingotomy may be associated with a better subsequent intrauterine pregnancy rate than salpingectomy. A number of case reports of pregnancies at unusual sites continue to be published, but in the last 2 years there has been a dramatic increase in the number of caesarean scar pregnancies reported.

SUMMARY

Medical therapy now has an established role in the treatment of ectopic pregnancy, but it is clear that careful patient selection is essential. In the surgical management of ectopic pregnancy the effects of salpingotomy and salpingectomy on subsequent fertility are uncertain and need further investigation.

Serum concentrations of interleukin-2R (IL-2R), IL-6, IL-8, and tumor necrosis factor alpha in patients with ectopic pregnancy

OBJECTIVE

To investigate the diagnostic relevance of serum cytokine concentrations in ectopic pregnancy (EP).

DESIGN

Cohort study.

SETTING

University hospital.

PATIENT(S)

Seventeen women with EP, 22 women with miscarriage, and 33 women with normal intrauterine pregnancy, at comparable stages of gestation.

INTERVENTION(S)

Interleukin (IL)-2 receptor, IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) determination by immunoradiometric assay.

MAIN OUTCOME MEASURE(S)

Serum concentrations of progesterone, beta-hCG, IL-2R, IL-6, IL-8, and TNF-alpha.

RESULT(S)

Serum levels of IL-6 were higher in women with EP than in those with miscarriage and normal pregnancy. Serum levels of TNF-alpha were higher in women with EP than in those with miscarriage and normal pregnancy. Serum levels of IL-8 were higher in women with EP than in those with miscarriage and normal pregnancy. An IL-8 cutoff of >40 pg/mL predicted EP with a sensitivity of 82.4%, a specificity of 81.8%, and positive and negative predictive values of 58.3% and 93.8%. No difference in serum IL-2R levels was found among the groups.

CONCLUSION(S)

Serum IL-8, IL-6, and TNF-alpha concentrations are higher in women with EP than in those with miscarriage and normal pregnancy. Further studies are needed to determine their diagnostic value.

Evaluation of serum creatine kinase in ectopic pregnancy with reference to tubal status and histopathology

OBJECTIVE

To study the value of creatine kinase in ectopic pregnancy with reference to tubal histopathology.

DESIGN

Prospective controlled study.

SETTING

Academic tertiary-care institution.

POPULATION

Thirty-two women with ectopic pregnancy and 20 controls with intrauterine pregnancies.

METHODS

Creatine kinase and beta-hCG levels were measured on admission. Ectopic pregnancies were removed at surgery and examined histologically.

MAIN OUTCOME MEASURES

Tubal localisation and integrity of ectopic pregnancies as judged at surgery and later histologically, and placental growth patterns in unruptured ectopic pregnancies classified as intraluminal, extraluminal or mixed as determined histologically.

RESULTS

Creatine kinase levels were higher in isthmic than ampullary ectopic pregnancies (P = 0.011), and higher in ruptured than in unruptured cases (P = 0.003) and normal pregnancies (P < 0.0001). A creatine kinase value >120iu/L was 65% sensitive and 87% specific in discriminating ruptured from unruptured ectopic pregnancies. Creatine kinase levels were above this cutoff in two of five unruptured ampullary ectopic pregnancies with invasive trophoblastic growth, yet in none of nine cases with intraluminally confined placentation (P = 0.04). Creatine kinase was positively correlated with gestational age in ruptured (P = 0.007), but not in unruptured ectopic pregnancies or normal pregnancies.

CONCLUSIONS

Serum creatine kinase may help in discriminating ruptured from unruptured ectopic pregnancies, while it is not useful for the primary diagnosis of ectopic pregnancy. An increase in creatine kinase levels accompanying muscular damage in ectopic pregnancy probably antedates tubal rupture, and may be related to trophoblastic growth patterns.

Serum levels of myoglobin, creatine phosphokinase, and smooth muscle heavy-chain myosin in patients with ectopic pregnancy

STUDY OBJECTIVE

Serum markers of smooth muscle destruction have been shown to be elevated in ectopic pregnancy, but they remain of questionable clinical utility. Our goal was to determine the clinical utility of 3 markers of smooth muscle destruction: creatine phosphokinase (CPK), smooth muscle heavy-chain myosin (SMHC), and myoglobin.

METHODS

This was a prospective cohort study, with consecutive enrollment of all women in the first trimester of pregnancy who presented to our urban emergency department with complaints of lower abdominal pain, vaginal bleeding, or both. Patients were excluded from the study if there was a history of recent surgery or major trauma. Data analysis included receiver operating characteristic (ROC) curve, 95% confidence intervals (CIs), and a regression model.

RESULTS

A total of 378 patients were enrolled, with 61 patients diagnosed with an ectopic pregnancy, and 317 patients placed in the non-ectopic pregnancy group with other diagnoses. ROC curve analysis revealed an area under the curve of 0.56 (95% CI 0.51 to 0.61) for CPK, 0.63 (95% CI 0.59 to 0.68) for SMHC, and 0.58 (95% CI 0.53 to 0.63) for myoglobin. A regression model analyzing the effects of race, maternal age, estimated gestational age, and serum levels of human chorionic gonadotropin beta-subunit found no significant confounders.

CONCLUSION

Although there is a statistically significant elevation in the serum levels of SMHC, the range of values seen is too large to allow SMHC to be a useful screening tool.

Serum levels of smooth muscle heavy-chain myosin in patients with ectopic pregnancy

STUDY OBJECTIVE

Previous studies have suggested that serum markers of smooth muscle destruction have utility in predicting ectopic pregnancy. Our goal was to determine whether a novel marker of muscle destruction, smooth muscle heavy-chain myosin (SMHC), is elevated in the serum of patients with ectopic pregnancy.

METHODS

We conducted a prospective cohort study, with consecutive enrollment, of all women in the first trimester of pregnancy who presented to our urban emergency department with complaints of lower abdominal pain with or without vaginal bleeding. Patients were excluded if there was a history of recent surgery or major trauma. Means were compared using 2-tailed Student's t test with P values less than.05 set for significance. Data analysis included calculation of receiver operating characteristic (ROC), 95% confidence intervals (CIs), and a regression model.

RESULTS

A total of 175 patients were enrolled; ectopic pregnancy was diagnosed in 29, and 146 had other diagnoses. Patients with ectopic pregnancy had a mean serum SMHC concentration of 2.53 ng/dL (95% CI 1.84 to 3.22), whereas those in the non-ectopic pregnancy group had a mean concentration of 1.41 ng/dL (95% CI 1.23 to 1.60; P <.0001). ROC analysis demonstrated an area under the curve of 0.72 (95% CI 0.65 to 0.79). Regression analysis to examine confounders in each group analyzed the effects of race, maternal age, estimated gestational age, and serum levels of human chorionic gonadotropin beta-subunit. Our analysis identified only a positive correlation between estimated gestational age and SMHC in the non-ectopic pregnancy group.

CONCLUSION

There is a statistically significant elevation of serum SMHC levels in tubal pregnancy, although our data suggest that the assay has limited clinical utility as a lone marker for ectopic pregnancy. Further investigation is needed to determine whether the assay has a role as an adjunct in the evaluation of suspected ectopic pregnancy.

Early diagnosis of ectopic pregnancy: can we do it accurately using a biochemical profile?

We wanted to evaluate the utility of seven biochemical markers in the early diagnosis of ectopic pregnancy. Women with pain and bleeding suspicious for ectopic pregnancy were evaluated prospectively. Each woman had a transvaginal sonogram and serum determination of beta-human chorionic gonadotropin (beta-hCG), progesterone, estradiol (E2), creatine phosphokinase (CPK), CA-125, 17-hydroxyprogesterone, and androstenedione. The women were grouped in two ways, and there was considerable overlap between the two groups. One grouping included those with <45 days of amenorrhea, and the other included those whose beta-hCG was <2500 mIU/ml. Each marker was analyzed by univariate and multivariate logistic regression to see which could best distinguish ectopic pregnancies from nonectopic pregnancies. In the group of women with <45 days of amenorrhea, ectopic pregnancies were distinguished by a low progesterone and a high CPK. None of the other biochemical markers were significantly associated with ectopic pregnancy in the multivariate logistic regression analysis. A receiver operating characteristic (ROC) curve was constructed for the CPK/progesterone ratio. As an example of different cut points, a CPK/progesterone ratio >15 was 87% sensitive and 83% specific in the diagnosis of ectopic pregnancy. In the group of women with beta-hCG <2500 mIU/ml, the only biochemical marker found to be significantly associated with ectopic pregnancy was CPK. An ROC curve was constructed for CPK in this group. As an example of different cut points, a CPK >70 had a 78% sensitivity and 81% specificity in the diagnosis of ectopic pregnancy. We conclude that the CPK/progesterone ratio is helpful in those women with <45 days of amenorrhea, and serum CPK levels are helpful in women whose beta-hCG is <2500 mIU/ml. Although serum levels of CPK and the ratio of CPK/progesterone are the most helpful in making the diagnosis of early ectopic pregnancy, they are not good enough to be used alone in clinical practice.

Evaluation of serum creatine kinase as a diagnostic marker for tubal pregnancy

Forty women comprising of 20 each in study and control groups had their serum creatine kinase (CK) estimated. The study subjects were proven cases of ectopic pregnancy and the controls were either medical termination of pregnancy seekers or antenatal cases matched for gestational age and with a confirmed intrauterine pregnancy. Total serum creatine kinase levels were found to be significantly higher in the study group i.e. 34.15 +/- 1.17 IU/L compared to the controls 18.72 +/- 1.25 (p < 0.001). Creatine kinase is estimated routinely in cardiac patients even on an emergency basis. Our findings indicate that when in doubt the test could be used as a marker for the diagnosis of ectopic pregnancy.

Serum progesterone and endovaginal sonography by emergency physicians in the evaluation of ectopic pregnancy

OBJECTIVE

To determine a discriminatory level for serum progesterone (SP) in pregnant patients with no definite intrauterine pregnancy (IUP) on endovaginal ultrasonography (US) in the differentiation of ectopic pregnancy from normal IUPs.

METHODS

A prospective observational study in a convenience sample of women at risk for ectopic pregnancy was performed at an urban teaching hospital from May 1991 until May 1994. Women aged > or =18 years presenting to the ED with a positive pregnancy test in combination with pelvic or abdominal pain, vaginal bleeding, orthostasis, adnexal mass or tenderness, or any historical risk factor for ectopic pregnancy were eligible. Hypotensive or unstable patients were excluded. Endovaginal US was performed and patients with no definite IUP had a serum beta-hCG and SP measured.

RESULTS

314 patients were enrolled, with 14 excluded for lack of follow-up or incomplete SP data, yielding 300 patients. The initial endovaginal US diagnoses included 169 definite IUP, 31 abnormal IUP, 5 definite ectopic pregnancy, and 95 no definite IUP. 68/95 had SP measured, with values of 22.8 +/- 13.4 ng/mL (mean +/- SD) for IUP; 4.9 +/- 6.5 for spontaneous abortion, and 7.5 +/- 7.2 for ectopic pregnancy. The mean values were significantly different (2-tailed t-test) for ectopic pregnancy vs IUP and for spontaneous abortion vs IUP. An SP of > or =11 ng/mL (sensitivity 91%; specificity 84%) was post hoc the best cutoff value for suggesting an IUP when the endovaginal US was not definite for IUP.

CONCLUSIONS

SP cannot reliably discriminate ectopic pregnancy vs spontaneous abortion in pregnant patients with no definite IUP on endovaginal US; however, a low SP (<11 ng/mL) in this sonographic category suggests an abnormal pregnancy.

Serum creatine kinase is an unreliable predictor of ectopic pregnancy

OBJECTIVE

To compare serum creatine kinase (CK) values in patients with ectopic pregnancy vs patients with threatened miscarriage or normal pregnancy.

METHODS

An observational case-control study was performed at an urban teaching hospital. Pregnant women with a quantitative beta-hCG obtained for suspicion of ectopic pregnancy were evaluated. Excluded were cases with recent trauma, i.m. injections, surgery, or history of heart, liver, or muscle disease. The serum beta-hCG and CK values were recorded and compared between groups with 1-way ANOVA and Tukey's multiple comparison procedure at the overall 0.05 level.

RESULTS

The 15 ectopic, 28 threatened miscarriage, and 21 normal pregnancy cases were of similar gestational ages (p = 0.2), ranging from 3 to 12 weeks. Although the CK values for ectopic pregnancy (88.8 +/- 33.6 IU/L) exceeded those for threatened miscarriage (65.9 +/- 59.0 IU/L) and normal pregnancy (56.0 +/- 38.1 U/L) (p = 0.02), there was significant overlap between groups. CK values were at or above a cutoff of 74 IU/L in 80% (95% confidence interval: 52-96%) of ectopic pregnancies, 25% (11-45%) of threatened miscarriages, and 14% (3-36%) of normal pregnancies.

CONCLUSIONS

Although the ectopic pregnancy population is characterized by a higher mean CK than are patients with threatened miscarriage or a normal pregnancy, a significant overlap in CK values makes use of this serum marker unreliable for detecting ectopic pregnancy.

Obstetric and gynecologic emergencies

This article reviews the pearls and pitfalls of obstetric and gynecologic emergencies occurring in women presenting to the emergency department. Some pitfalls include failure to screen for ectopic pregnancy, tachycardia as an unreliable indicator of a ruptured ectopic pregnancy, and the use of serum hCG as a testing procedure during pregnancy. Updates include serologic markers of ectopic pregnancy, ultrasonography in the emergency department, methotrexate treatment of ectopic pregnancy, traumatic placental separation, and fetomaternal hemorrhage.

Maternal serum creatine kinase does not predict tubal pregnancy

PURPOSE

Our purpose was to validate prospectively the predictive value of maternal serum creatine kinase in the evaluation of ectopic pregnancy.

METHODS

Fifty-one consecutive pregnant first-trimester patients who presented for suspected abnormal pregnancy were enrolled. Maternal serum samples were obtained and assayed for creatine kinase. Patients were subsequently evaluated for abnormal pregnancy by serial quantitative hCG levels, transvaginal ultrasonography, and surgery when appropriate. A receiver operating characteristic (ROC) curve was generated comparing intrauterine to extrauterine (ectopic) pregnancy.

RESULTS

Of 51 patients, 18 had an ectopic pregnancy, 16 had a spontaneous abortion, and 17 had an ongoing intrauterine pregnancy. The ROC curve revealed that maternal serum creatine kinase had no ability to predict ectopic pregnancy.

CONCLUSIONS

Maternal serum creatine kinase is not a reliable predictor of tubal pregnancy.

Is maternal serum creatine kinase actually a marker for early diagnosis of ectopic pregnancy?

OBJECTIVE

Our purpose was to investigate whether serum creatine kinase (CK) levels could be used as an early marker of ectopic pregnancy. Student's t-test was used for statistical analysis.

STUDY DESIGN

In a prospective study we therefore measured serum progesterone, beta hCG and CK levels in 30 women with ectopic pregnancies, 30 women with ongoing pregnancies and 30 women with missed abortion.

RESULTS

The mean serum CK concentration for patients with an ectopic pregnancy, ongoing pregnancy, and the women with missed abortion was 81.4 +/- 66.2, 81.5 +/- 40.3, 84.8 +/- 49.3, respectively. No relationship was found between CK level and the location of the pregnancy.

CONCLUSION

Conversely to the first report of Lavie et al. (Am J Obstet Gynecol 1993; 169: 1149), our data suggest that serum CK level is not discriminative in the early diagnosis of tubal pregnancy.

Failure of creatine kinase to predict ectopic pregnancy

OBJECTIVE

To investigate serum creatine kinase (CK) levels in pregnant women with ectopic pregnancy (EP), spontaneous abortion, and normal pregnancy with comparable serum hCG concentrations.

DESIGN

A retrospective, case-controlled study.

SETTING

Helsinki University Central Hospital, Helsinki, Finland.

PATIENTS

Forty-four patients with a suspicion of EP of which 15 had laparoscopically confirmed tubal pregnancies; 15 had a spontaneous abortion, a blighted ovum, or a missed abortion; and 14 patients a normal intrauterine pregnancy.

INTERVENTIONS

The diagnosis was made by transvaginal sonography and serum hCG determinations either at admission or after repeated examinations. Ectopic pregnancy was confirmed and treated by laparoscopy.

MAIN OUTCOME MEASURES

Serum CK and hCG levels.

RESULTS

No significant differences in CK levels were observed between the groups by one-way analysis of variance and no correlation was found between serum CK and hCG levels within any group.

CONCLUSIONS

Creatine kinase does not appear to be useful in the diagnosis of early EP.

Evaluation of serum creatine kinase levels in ectopic pregnancy

OBJECTIVE

To analyze whether increased serum creatine kinase (CK) levels are useful in early detection of ectopic pregnancy (EP).

DESIGN

Prospective cohort study.

SETTING

Patients in a university-based reproductive endocrinology and infertility practice.

PATIENTS

Infertile women who achieved clinical pregnancy.

INTERVENTIONS

Serum CK with isoenzymes levels were drawn after sonographic evaluation in patients achieving clinical pregnancy.

MAIN OUTCOME MEASURES

Comparison of serum CK levels in patients with EP versus those with normal and abnormal intrauterine pregnancy (IUP), both separately and together as one group.

RESULTS

There was no significant difference in mean total CK levels for patients with EP (82.25 +/- 81.39 IU/L; conversion factor to SI unit, 1.00) versus normal IUP (62.54 +/- 44.79 IU/L), abnormal IUP (55.15 +/- 3.46 IU/L), or all IUP (60.87 +/- 40.72 IU/L). The mean gestational ages were similar in all three groups: EP, 46.78 +/- 6.65 days; normal IUP, 47.56 +/- 8.29 days; and abnormal IUP, 47.86 +/- 13.30 days.

CONCLUSION

Serum CK levels do not help to predict EP for infertility patients achieving conception. To assist in preventing maternal morbidity, a more discriminative test is needed to identify this condition early in gestation.

Creatine kinase alterations after acute malignant hyperthermia episodes and common surgical procedures

Skeletal muscle may release creatine kinase (CK) during a malignant hyperthermia (MH) episode; however, muscle damaged during surgery may also release CK. This study examined the overlap between peak plasma CK levels in patients suspected of having had a MH episode (data obtained from North American MH Registry) and previously published CK changes occurring after common surgeries. For patients who were subsequently proven to be MH positive by muscle biopsy, there was considerable overlap. This was most significant with surgeries having substantial tissue damage, such as major vascular surgery and abdominal surgery. Overlap was much less with minimally invasive surgery, such as cystoscopy. Approximately 30% of MH positive patients treated with dantrolene had peak CK in the range of most surgical procedures, and approximately 50% of MH positive patients not given succinylcholine had peak CK similar to those of most surgical procedures. Dantrolene did not significantly alter peak CK in MH positive patients; however, succinylcholine was associated with significantly higher peak CK. These data suggest that patients who have had an acute MH episode during a surgical procedure may have peak CK values within the range of CK values expected from the procedure itself.

Measurement of creatine kinase activity and diagnosis of ectopic pregnancy

OBJECTIVE

To investigate whether the measurement of maternal plasma creatine kinase concentration is of clinical value in the diagnosis of tubal ectopic pregnancy.

DESIGN

A retrospective observational study covering a three month period.

SETTING

The gynaecological emergency service of a UK teaching hospital.

SUBJECTS

One hundred and twenty women presenting with clinical suspicion of an ectopic pregnancy such that plasma human chorionic gonadotrophin (hCG) concentration was measured.

MAIN OUTCOME MEASURES

Plasma hCG and creatine kinase concentrations were measured. Pregnancies were classified as ectopic pregnancy, complete miscarriage, incomplete miscarriage or ongoing pregnancy. Pregnancies were further classified as uncertain diagnosis if the diagnosis was not clear after initial investigation.

RESULTS

Twenty-one of the patients had an ectopic pregnancy. Diagnosis was classified as uncertain in 48% of pregnancies studied and in 54% of ectopic pregnancies during the study period. The mean plasma creatine kinase was higher in ectopic pregnancies than other pregnancies in the study group (P < 0.01) and remained higher in the subgroup of patients with uncertain diagnosis (P < 0.05) but there were significant overlaps in creatine kinase concentrations in all four clinical groups. When a cut-off point of 45 iu/l is used, the measurement of plasma creatine kinase activity has a sensitivity of 0.57 and a specificity of 0.67 for the diagnosis of ectopic pregnancy.