Clinical value of creatinine kinase in the diagnosis of ectopic 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.

Ectopic pregnancy: diagnosis and management

The incidence of ectopic pregnancies is increasing, which may be related to better diagnostic tools as well as the increasing use of assisted reproductive technologies. However, the signs and symptoms of ectopic pregnancy can be similar to other complications of early pregnancy such as miscarriage. Diagnosis often requires serial human chorionic gonadotropin levels along with ultrasound and, in some cases, dilation and curettage. Once a diagnosis has been made, treatment options include medical therapy with methotrexate and surgery, which can often be performed via the laparoscope. Fertility rates after therapy are similar for both medically and surgically treated patients.

Serum markers in the diagnosis of tubal pregnancy

The introduction of highly sensitive methods, such as transvaginal sonography and measurement of serum b-human chorionic gonadotropin, has dramatically improved ectopic pregnancy diagnosis in recent years. Early diagnosis is the key to successful and conservative management of women with ectopic pregnancy; however, approximately 50 percent of such women are initially misdiagnosed, resulting in significant morbidity and mortality. In order to improve diagnosis, several serum markers are being investigated including progesterone, CA 125, pregnancy-associated plasma protein-A, vascular endothelial growth factor, and maternal creatine kinase. Measurement of serum vascular endothelial growth factor, alone or together with other markers, could be a promising method for earlier and more accurate differential diagnosis. However, the clinical applicability of these findings remains to be evaluated in larger prospective studies.

Serum biochemical parameters and embryo production during superovulatory treatment in dairy cattle

The objective of this study was to determine the relationship between the number of transferable embryos (TE) and various blood chemistry parameters as a reflection of the metabolic state of cows after superovulatory treatment. Forty-nine Holstein cows were subjected to superovulatory treatment for commercial embryo production. At the time of embryo harvest, individual blood samples were taken from cows for biochemical analysis. All embryos including dead ones as well as non-fertilized oocytes were counted in uterine lavage. Feed samples collected daily for a period of two weeks before embryo harvest, were analyzed for mycotoxins: vomitoxin, zearalenone and T-2 toxin. On average, cows produced 9.45+/-5.60 embryos and oocytes of which 5.27+/-4.20 were TE, 0.37+/-0.80 were dead embryos and 3.82+/-3.78 were non-fertilized oocytes. Higher concentrations of Mg and K were associated with a higher production of TE (p=0.005 and p=0.043, respectively) and higher activity of creatinine kinase was associated with a lower production of TE (p=0.011).

Suspected Ectopic Pregnancy

Women who present with pain and bleeding in the first trimester are at risk for ectopic pregnancy, a life-threatening condition. Conditions that predispose a woman to ectopic pregnancy are damaged fallopian tubes from prior tubal surgery or previous pelvic infection, smoking, and conception using assisted reproduction. Many women without risk factors can develop an ectopic pregnancy. A diagnostic algorithm that includes the use of transvaginal ultrasonography, human chorionic gonadotropin (hCG) concentrations, and, sometimes, uterine curettage can definitively diagnose women at risk in a timely manner. The absence of an intrauterine pregnancy above an established cut point of hCG is consistent with an abnormal pregnancy but does not distinguish a miscarriage from an ectopic pregnancy. When the initial hCG value is low, serial hCG values can be used to determine whether a gestation is potentially viable or spontaneously resolving. The minimal rise in hCG for a viable pregnancy is 53% in 2 days. The minimal decline of a spontaneous abortion is 21-35% in 2 days, depending on the initial level. A rise or fall in serial hCG values that is slower than this is suggestive of an ectopic pregnancy. Women diagnosed with an unruptured ectopic pregnancy are potential candidates for medical management with methotrexate. Intramuscular injection with methotrexate can be used to safely treat an ectopic pregnancy with success rates, tubal patency rates, and future fertility that are similar to those obtained with conservative surgery. Success rates using methotrexate are inversely rated to baseline hCG values and are higher using "multidose" compared with "single-dose" regimens. Surgical treatment may be conservative or definitive and should be attempted in most cases via laparoscopy.

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.