Twin pregnancies with uterine fibroids are not at increased risk for obstetric complications: single center cohort study.

BACKGROUND: Twin pregnancies with uterine fibroid(s) (UFs) may not be at increased risk for obstetric complications compared to those without UFs. However, there was no reported comparison study with obstetric outcomes and complications of twin pregnancy after myomectomy. We aimed to compare the pregnancy outcomes in twin pregnancies with or without uterine fibroid(s), and also compared in patients with previous myomectomy history in Korean women. METHODS: A cohort of twin pregnancies delivered in a single institution between January 2011 and March 2019 were retrospectively analyzed. UFs group was defined by the presence of UFs during pregnancy (≥1 fibroid, measuring ≥2 cm or multiple fibroids regardless of the size). Previous myomectomy group included patients with history of abdominal or laparoscopic or hysteroscopic myomectomy of ≥1 fibroid, measuring ≥2 cm or multiple fibroids whatever the size. Patients with monochorionic monoamniotic twins, myoma less than 2 cm in size, missed abortion or intrauterine fetal death (IUFD) of one fetus before 14 weeks, history of previous conization, and uterine anomalies were excluded. Pregnancy outcomes and obstetric complications were compared. RESULT: A total 1388 patients were included in this study, 191 (13.8%) had UFs and 89 (6.4%) had a history of myomectomy. Maternal age was younger in non-UFs group and primiparity was more common in UFs group (p < 0.001, and p = 0.019). No significant differences were found in the gestational age at delivery (p = 0.657), delivery before 37 weeks (p = 0.662), delivery before 34 weeks (p = 0.340), and sum of birth weight of twin (p = 0.307). There were also no statistical differences in rates of obstetrical complications, such as preeclampsia, gestational diabetes mellitus, placenta previa, placenta abruption, cerclage, small for gestational age, IUFD, postpartum hemorrhage and peripartum transfusion or ICU care. These obstetrical outcomes and complications showed no statistical differences between UFs group and previous myomectomy group. CONCLUSION: In patients with twin pregnancies, the presence of UFs or history of previous myomectomy did not relate to negative effects on pregnancy outcomes and obstetrical complications.

Clinical outcomes of prophylactic compression sutures for treatment of uterine atony during the cesarean delivery of twins.

BACKGROUND: Twin pregnancy has a high risk for developing uterine atony (UA). This study aimed to evaluate efficacy and clinical outcomes of prophylactic compression sutures to treat UA during twin cesarean section (CS). METHODS: All patient records of twin deliveries by CS after gestational age of 24 weeks in a large maternity hospital in South Korea between January 2013 and June 2018 were reviewed. Patients with monochorionic monoamniotic twins were excluded from data analysis. In total, 953 women were eligible for data analysis. RESULTS: Of the 953 patients, compression sutures were applied to 147 cases with postpartum bleeding that were refractory to uterine massage and uterotonics. Out of the 147, two patients (1.4%) proceeded to additional uterine artery ligation to achieve hemostasis, yielding a success rate of 98.6%. The rate of transfusion after the first 24 h of delivery in the suture group was not significantly different from that in the non-suture group, suggesting that both groups achieved hemostasis at an equal rate after the first 24 h of delivery. The difference in the operation time between the two groups was only 8.5 min. The rate of subsequent pregnancy among the patients who received compression sutures was 44.4%. CONCLUSIONS: Overall, our findings suggest that with early and fast implementation of compression sutures, UA can be treated in the setting of twin cesarean delivery without significantly increasing maternal morbidity.

Evidence for No Significant Impact of Müllerian Anomalies on Reproductive Outcomes of Twin Pregnancy in Korean Women.

The present article aimed to evaluate the impact of congenital Müllerian anomalies (MA) on twin pregnancy after 24 gestational weeks in Korean women. All records of twin pregnancies in a large maternity hospital in Korea between January 2005 and July 2013 were analyzed. Patients with monochorionic monoamniotic (MCMA) twins, non-Korean patients, patients with twins delivered prior to 24 gestational weeks, and patients with miscarriage of one fetus or intrauterine fetal death (IUFD) before 24 gestational weeks were excluded from data analysis. In total, 1,422 women with twin pregnancy were eligible for data analysis, including 17 (1.2%) who had a known congenital MA (septate uterus, bicornuate uterus, arcuate uterus, and unicornuate uterus). Except for the mode of conception, baseline demographics were similar between women with MA and those without MA. No significant differences were found in pregnancy outcomes of gestational age at delivery (p = .86), birth weight of smaller and larger twins (p = .54 and p = .65), and number of twins with birth weight <5th percentile for gestational age (p = .43).The rates of obstetrical complications such as pre-eclampsia, gestational diabetes mellitus (GDM), placenta previa, cerclage, IUFD, and postpartum hemorrhage were not significantly different between the two groups either. We concluded that the presence of congenital MA may not increase obstetrical risks in outcomes of pregnancy of twins delivered after 24 gestational weeks.

Pregnancy Outcomes and Obstetrical Complications of Twin Pregnancies with Endometriosis: A Single-Center Cohort Study.

PURPOSE: There are many studies regarding the increased relationship between pregnancy outcomes of singleton with endometriosis. However, there was limited evidence of twin pregnancies with endometriosis. This study aimed to compare the pregnancy outcomes and complications in twin pregnancies with or without endometriosis in a single institution. MATERIALS AND METHODS: From January 2011 to July 2022, a retrospective analysis of twin pregnancies was conducted. The endometriosis group included patient with histological or visual confirmation before pregnancy or during cesarean section. Pregnancy outcomes and complications were compared between the two groups. RESULTS: Out of 1714 patients examined, 127 (7.4%) were included in the endometriosis group. Maternal body mass index (BMI) was lower in the endometriosis group (p<0.001). There were no significant differences in maternal age, mode of conception, chorionicity, and pregnancy outcomes, such as gestational age at delivery (p=0.835) and the preterm birth rate (p=0.579). The endometriosis group had a significantly higher rate of obstetrical complication: small for gestational age (SGA) <10% (p=0.029). However, after adjustment for BMI, the endometriosis group showed no statistical significance in obstetrical complications, including SGA (adjusted odds ratio, 1.568; 95% confidence interval, 0.984-2.499; p=0.059). CONCLUSION: Twin pregnancies with endometriosis were not related to adverse effects on pregnancy outcomes and obstetrical complications. To confirm these outcomes, further large prospective studies are required.

The Association between Low Fetal Fraction of Non-Invasive Prenatal Testing and Adverse Pregnancy Outcomes for Placental Compromise.

(1) Background: Non-invasive prenatal testing (NIPT) is a screening test for fetal aneuploidy using cell-free fetal DNA. The fetal fragments (FF) of cell-free DNA (cfDNA) are derived from apoptotic trophoblast of the placenta. The level of fetal cfDNA is known to be influenced by gestational age, multiple pregnancies, maternal weight, and height. (2) Methods: This study is a single-center retrospective observational study which examines the relationship between the fetal fraction (FF) of cell-free DNA in non-invasive prenatal testing (NIPT) and adverse pregnancy outcomes in singleton pregnancies. A total of 1393 samples were collected between 10 weeks and 6 days, and 25 weeks and 3 days of gestation. (3) Results: Hypertensive disease of pregnancy (HDP) occurred more frequently in the low FF group than the normal FF group (5.17% vs. 1.91%, p = 0.001). Although the rates of small for gestational age (SGA) and placental abruption did not significantly differ between groups, the composite outcome was significantly higher in the low FF group (7.76% vs. 3.64%, p = 0.002). Furthermore, women who later experienced complications such as HDP or gestational diabetes mellitus (GDM) had significantly lower plasma FF levels compared to those without complications (p < 0.001). After adjustments, the low FF group exhibited a significantly higher likelihood of placental compromise (adjusted odds ratio: 1.946). (4) Conclusions: Low FF in NIPT during the first and early second trimesters is associated with adverse pregnancy outcomes, particularly HDP, suggesting its potential as a predictive marker for such outcomes.

The South Korean Twin Registry: an update.

The South Korean Twin Registry (SKTR) is an ongoing nation-wide volunteer registry of South Korean twins and their families, which was established in the year 2001 to understand genetic and environmental etiologies of psychological and physical traits among South Koreans. Recently, the SKTR sampling has been extended in two important ways. First, we began to recruit twins from lower socio-economic families to study interaction effects of gene by environmental context. Second, as a parallel study of the SKTR, the Nigerian Twin and Sibling Registry was developed to understand the origin of the population group differences/similarities in psychological traits between South Koreans and Nigerians. This article summarizes the main findings (based on the SKTR sample to date), recruitment procedures, zygosity assessment, measures, and future plans for the SKTR.

The Nigerian Twin and Sibling Registry.

Twin studies of Africans have been scarce although Africans have shown the highest twin birth rate in the world. As a parallel study of the South Korean Twin Registry, the Nigerian Twin and Sibling Registry (NTSR) was developed to understand causal influences on the development of cognitive abilities, personality, and mental health among Nigerians. Currently, 1,134 twins and 404 full- and half-siblings have been registered with NTSR. This article describes research background, goals, major recruitment strategies, measures, and future directions of the NTSR.

Pomegranate juice and punicalagin attenuate oxidative stress and apoptosis in human placenta and in human placental trophoblasts.

The human placenta is key to pregnancy outcome, and the elevated oxidative stress present in many complicated pregnancies contributes to placental dysfunction and suboptimal pregnancy outcomes. We tested the hypothesis that pomegranate juice, which is rich in polyphenolic antioxidants, limits placental trophoblast injury in vivo and in vitro. Pregnant women with singleton pregnancies were randomized at 35∼38 wk gestation to 8 oz/day of pomegranate juice or apple juice (placebo) until the time of delivery. Placental tissues from 12 patients (4 in the pomegranate group and 8 in the control group) were collected for analysis of oxidative stress. The preliminary in vivo results were extended to oxidative stress and cell death assays in vitro. Placental explants and cultured primary human trophoblasts were exposed to pomegranate juice or glucose (control) under defined oxygen tensions and chemical stimuli. We found decreased oxidative stress in term human placentas from women who labored after prenatal ingestion of pomegranate juice compared with apple juice as control. Moreover, pomegranate juice reduced in vitro oxidative stress, apoptosis, and global cell death in term villous explants and primary trophoblast cultures exposed to hypoxia, the hypoxia mimetic cobalt chloride, and the kinase inhibitor staurosporine. Punicalagin, but not ellagic acid, both prominent polyphenols in pomegranate juice, reduced oxidative stress and stimulus-induced apoptosis in cultured syncytiotrophoblasts. We conclude that pomegranate juice reduces placental oxidative stress in vivo and in vitro while limiting stimulus-induced death of human trophoblasts in culture. The polyphenol punicalagin mimics this protective effect. We speculate that antenatal intake of pomegranate may limit placental injury and thereby may confer protection to the exposed fetus.

The promoter -1031(T/C) polymorphism in tumor necrosis factor-alpha associated with polycystic ovary syndrome.

BACKGROUND: A tumor necrosis factor-alpha is a multifunctional pro-inflammation cytokine, which has been considered as one of pathogenic factors for various diseases. The promoter -1031(T/C) polymorphism in the tumor necrosis factor-alpha gene was reported that it plays a part in reproduction-related diseases. Among these, polycystic ovary syndrome (PCOS) is known to be a common gynecological disease of women in reproductive age women. Here, we performed a comparative study of -1031(T/C) polymorphism of TNF-alpha gene with PCOS in a Korean population. METHODS: The -1031(T/C) polymorphism of TNF-alpha gene was analyzed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) in a total of 217 PCOS patients and 144 matched female controls of healthy women. And statistical analysis was performed using HapAnalyzer. X2 test and logistic regression were utilized analyze the association between two groups. A p-value under 0.05 was considered statistically significant. RESULTS: The genotype and allelic frequencies were in Hardy-Weinberg equilibrium (HWE). There was strong association between the -1031(T/C) polymorphism in the promoter region of TNF-alpha gene and PCOS (p-value = 0.0003, odd ratio (OR) = 2.53). In addition, the frequency of C allele was significantly higher in PCOS patients compared with controls. Sequence analyses also showed the -1031(T/C) polymorphism of TNF-alpha gene. CONCLUSION: This is the first study on the -1031(T/C) polymorphism of TNF-alpha gene in PCOS. We concluded that the -1031(T/C) polymorphism of TNF-alpha gene is associated with PCOS in a Korean population. Therefore, it is possible that it may be considered as a clinical biomarker to diagnose for PCOS, and is helpful in understanding the etiology for the pathogenesis of PCOS.

The South Korean Twin Registry.

The South Korean Twin Registry (SKTR), previously called the Seoul Twin Family Study, is a nationwide volunteer registry of South Korean twins and their families. Since 2002, the SKTR has been updated in 4 important ways. First, continued sampling led to an increase in the number of twins. Second, the target area, Seoul, was enlarged to include other cities and rural areas in the country. Third, the target population was extended from school-aged twins to preschool and adult twins. Fourth, the research focus was expanded to include psychiatric and physical disease phenotypes. The present article describes a brief history of the SKTR, goals and current research highlights, recent major accomplishments, and future directions.

Risk factors for acute postpartum urinary retention after vaginal delivery: focus on episiotomy direction.

OBJECTIVE: This study aimed to investigate the independent factors for acute postpartum urinary retention (APUR) after vaginal delivery. METHODS: From January 2008 to December 2013, 98 patients with APUR after vaginal delivery without instrument use were compared with 108 control patients matched by age and medical history. Multivariate logistic regression analysis was performed to identify independent risk factors for APUR. Predictive accuracy for the multivariate model was assessed using the derived area under a receiver operating characteristics curve. RESULTS: Among maternal previous partial history, mean live birth history was lower in the APUR group (0.12 versus 0.31, p = 0.017). Regional anesthesia use (76.5% versus 60.2%, p = 0.036), mediolateral episiotomy (63.3% versus 31.5%, p < 0.001) and labor time were significantly higher in the APUR group. Multivariate logistic regression analysis showed that mediolateral episiotomy, labor time and the presence of regional anesthesia were independent contributing factors for the development of APUR. This model's predictive accuracy for APUR was 73.1%. CONCLUSION: Prolonged labor time, regional anesthesia and mediolateral episiotomy were independent factors for APUR. Therefore, we considered median episiotomy to be the best approach during vaginal delivery avoiding APUR.

Alteration of Pituitary Tumor Transforming Gene-1 Regulates Trophoblast Invasion via the Integrin/Rho-Family Signaling Pathway.

Trophoblast invasion ability is an important factor in early implantation and placental development. Recently, pituitary tumor transforming gene 1 (PTTG1) was shown to be involved in invasion and proliferation of cancer. However, the role of PTTG1 in trophoblast invasion remains unknown. Thus, in this study we analyzed PTTG1 expression in trophoblasts and its effect on trophoblast invasion activity and determined the mechanism through which PTTG1 regulates trophoblast invasion. Trophoblast proliferation and invasion abilities, regardless of PTTG1 expression, were analyzed by quantitative real-time polymerase chain reaction, fluorescence-activated cell sorting analysis, invasion assay, western blot, and zymography after treatment with small interfering RNA against PTTG1 (siPTTG1). Additionally, integrin/Rho-family signaling in trophoblasts by PTTG1 alteration was analyzed. Furthermore, the effect of PTTG1 on trophoblast invasion was evaluated by microRNA (miRNA) mimic and inhibitor treatment. Trophoblast invasion was significantly reduced through decreased matrix metalloproteinase (MMP)-2 and MMP-9 expression when PTTG1 expression was inhibited by siPTTG1 (p < 0.05). Furthermore, knockdown of PTTG1 increased expression of integrin alpha 4 (ITGA4), ITGA5, and integrin beta 1 (ITGB1); otherwise, RhoA expression was significantly decreased (p < 0.05). Treatment of miRNA-186-5p mimic and inhibitor controlled trophoblast invasion ability by altering PTTG1 and MMP expression. PTTG1 can control trophoblast invasion ability via regulation of MMP expression through integrin/Rho-family signaling. In addition, PTTG1 expression and its function were regulated by miRNA-186-5p. These results help in understanding the mechanism through which PTTG1 regulates trophoblast invasion and thereby implantation and placental development.

A comparison of twin birthweight data from Australia, the Netherlands, the United States, Japan, and South Korea: are genetic and environmental variations in birthweight similar in Caucasians and East Asians?

Birthweight has implications for physical and mental health in later life. Using data from Caucasian twins collected in Australia, the Netherlands and the United States, and from East Asian twins collected in Japan and South Korea, we compared the total phenotypic, genetic and environmental variances of birthweight between Caucasians and East Asians. Model-fitting analyses yielded four major findings. First, for both males and females, the total phenotypic variances of birthweight were about 45% larger in Caucasians than in East Asians. The larger phenotypic variances were mainly attributable to a greater shared environmental variance of birthweight in Caucasians (ranging from 62% to 67% of variance) than Asians (48% to 53%). Second, the genetic variance of birthweight was equal in Caucasians and East Asians for both males and females, explaining a maximum of 17% of variance. Third, small variations in total phenotypic variances of birthweight within Caucasians and within East Asians were mainly due to differences in nonshared environmental variances. We speculate that maternal effects (both genetic and environmental) explain the large shared environmental variance in birthweight and may account for the differences in phenotypic variance in birthweight between Caucasians and East Asians. Recent molecular findings and specific environmental factors that are subsumed by maternal effects are discussed.

The relation between fetal nasal bone length and biparietal diameter in the Korean population.

OBJECTIVE: To evaluate the relation between fetal nasal bone length (NBL) and biparietal diameter (BPD) at 15-19.9 (20) weeks of gestation by ultrasonography in the Korean population. METHODS: The study population included 1268 Korean women (aged between 19 and 45 years) with a singleton pregnancy who registered at the Maternal Fetal Medicine Unit of Samsung Cheil Hospital between September 2003 and February 2005. Ultrasound measurements of NBL were performed using a strict sagittal plan of the fetal head. Other fetal biometry profiles were conducted before amniocentesis for fetal karyotyping. RESULTS: NBL and fetal biometry profiles were measured successfully in 77.9% (988/1268) of the fetuses. NBL was found to increase linearly as a function of BPD (P < 0.001) with a median NBL of 4.4 mm (range 1.9-7.9). NBL increases through 15-19.9 (20) weeks of gestation were given by the equation NBL (mm) = 0.0836 x BPD (mm) + 1.368 (R2 = 0.1, P < 0.001). CONCLUSIONS: Fetal NBL and BPD are linearly related in the second trimester. Fetal NBL in the Korean population is likely to be shorter than that reported for Caucasians and African-Americans.

Maternal serum and amniotic fluid inhibin A levels in women who subsequently develop severe preeclampsia.

The purpose of this study was to evaluate whether maternal serum (MS) and amniotic fluid (AF) inhibin A levels are elevated in patients who subsequently develop severe preecalmpsia, and to investigate the correlation between MS and AF inhibin A levels in the second trimester. The study included 40 patients who subsequently developed severe preecalmpsia and 80 normal pregnant women. Inhibin A levels in MS and AF were measured with enzyme-linked immunosorbent assay (ELISA). The MS and AF inhibin A levels in patients who developed severe preeclampsia were significantly higher than those in the control group (both for p<0.001). There was a positive correlation between MS and AF inhibin A levels in patients who developed severe preeclampsia (r=0.397, p=0.011), but not in the control group (r=0.185, p=0.126). The best cutoff values of MS and AF inhibin A levels for the prediction of severe preeclampsia were 427 pg/mL and 599 pg/mL, respectively; the estimated ORs that were associated with these cut-off values were 9.95 (95% CI 3.8-25.9, p<0.001) and 6.0 (95% CI 2.3-15.8, p<0.001). An elevated level of inhibin A in MS and AF at the time of second trimester amniocentesis may be a risk factor for the subsequent development of severe preeclampsia.

Perinatal outcome in twin pregnancies complicated by gestational diabetes mellitus: a comparative study.

The purpose of this study is to compare perinatal outcomes of twin pregnancies complicated by gestational diabetes (GDM) with those unaffected by GDM. A total of 1,154 twin pregnancies who delivered at Cheil General Hospital, between January 1998 and December 2002 were recruited to participate in a retrospective analysis. Out of these twin pregnancies, 37 women were had GDM. Four pregnancies exposed to GDM were excluded due to the loss of medical records; therefore 33 twin pregnancies exposed to GDM were enrolled. We matched the GDM pregnancies with pregnancies unaffected by GDM in a 1:2 ratio; therefore there were 33 GDM/66 without GDM who delivered during the study period. Our findings show that there were no significant differences including birth weight, Apgar score, respiratory distress syndrome, meconium aspiration pneumonia, transient tachypnea of new born, hyperbilirubinemia, hypoglycemia, hypocalcemia and congenital anomalies. Therefore, well controlled GDM may not increase perinatal complications in twin pregnancies. Careful pregnancy management and fetal surveillance in twin pregnancies is important to decrease perinatal complications and maintain a sound pregnancy and healthy offspring.

Threshold of nuchal translucency for the detection of chromosomal aberration: comparison of different cut-offs.

This study evaluated the sensitivities and false positive rates of the screening test using ultrasonographic measurement of thickness of nuchal translucency (NT) with different cut-offs for chromosomal aberration in a Korean population. We included 2,570 singleton pregnancies undergoing ultrasound between 11 weeks and 14 weeks of gestation in this study. We analyzed the sensitivities of NT alone for screening chromosomal aberration using three cut-offs -2.5 mm, 3.0 mm, and 95th percentile for each crown rump length (CRL). There were 31 chromosomal aberrations (1.2%) including 12 cases of trisomy 21. The numbers of chromosomal aberrations that were detected by NT with different cut-offs of 2.5 mm, 3.0 mm and the 95th percentile CRL were 22, 18 and 23, respectively. At a threshold of 2.5 mm, the sensitivity and the false positive rate for total chromosomal aberrations were 67.7% and 6.3%, respectively. At 3.0 mm, those were 54.8% and 3.5%, respectively. At the 95th percentile CRL, those were 70.9% and 5.8%, respectively. The use of CRL-dependent cut-offs for nuchal translucency improves the detection of chromosomal aberrations when compared to fixed cut-offs in a Korean population.

Prenatal diagnosis of trisomy 18: report of 30 cases.

OBJECTIVES: To review the detection rate of the prenatal screening tests used for the diagnosis of the trisomy 18. METHODS: From 1 October 1998 to 31 December 2001, we reviewed the database and medical records of 30 cases of trisomy 18. All were singletons and trisomy 18 was confirmed by amniocentesis in 19 cases, by cordocentesis in 6 cases, by chorionic villi sampling in 2 cases and by skin biopsy in 3 cases. RESULTS: Of the 30 study cases, 23 cases (77%) were offered genetic study due to abnormal ultrasound (US) findings. Twelve (40%) out of the 23 cases were due to abnormal US findings detected before the triple test and 11 (37%) were due to abnormal US findings after the normal triple test. Six cases (20%) were offered genetic study because of an abnormal triple test, and one case was offered genetic study due to advanced maternal age only. Including the second targeted ultrasonogram, one or more abnormal US findings were found in all 30 fetuses. CONCLUSIONS: Abnormal US finding is the most sensitive screening test for trisomy 18. The most sensitive ultrasonographic finding for trisomy 18 at under 16 weeks of gestation is increased nuchal translucency (75%) and, after 16 weeks, is cardiac defect (83%).

Clinical effectiveness of urinary human chorionic gonadotropin related protein (hCGRP) quantification for diagnosis of ectopic pregnancy.

We detected pregnancy related new molecule, human chorionic gonadotropin related protein (hCGRP) in the urine of a pregnant women by using a monoclonal antibody against the human chorionic gonadotropin (hCG). This study examined the effectiveness of urinary hCGRP quantification in diagnosing ectopic pregnancy. This study included 40 normal pregnant women and 25 patients with ectopic pregnancy. Patients' serum and urinary intact whole hCG (i-hCG) and hCGRP concentrations were measured using sandwich ELISA and the ratio of hCGRP to i-hCG was calculated. Statistical analysis was performed using statistical package for social sciences (SPSS) 10.0. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the cut-off value to discriminate ectopic pregnancies from normal intrauterine pregnancies. Urinary hCGRP and hCGRP/i-hCG ratio in ectopic pregnancy group (14 +/- 6.6 ng/mL, 4.6 +/- 1.9%, respectively) were significantly lower than those of normal pregnancy group (149 +/- 10.2 ng/mL, 29.7 +/- 1.9%, respectively; p<0.001). Based on ROC curve analysis, a cut-off point of urinary hCGRP/i-hCG ratio <16.2% discriminated between ectopic pregnancy and normal pregnancy with a sensitivity, specificity, positive predictive value and negative predictive value of 92.0%, 90.0%, 32.6%, and 99.5%, respectively. Urinary hCGRP/i-hCG ratio measurement may be effective in diagnosing ectopic pregnancy.