Maternal Plasma and Amniotic Fluid LBP, Pentraxin 3, Resistin, and IGFBP-3:Biomarkers of Microbial Invasion of Amniotic Cavity and/or Intra-amniotic Inflammation in Women with Preterm Premature Rupture of Membranes

Background@#We sought to determine whether lipopolysaccharide binding protein (LBP), pentraxin 3, resistin, and insulin-like growth factor binding protein (IGFBP)-3 in plasma and amniotic fluid (AF) can predict microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation (IAI), and microbial-associated IAI in women with preterm premature rupture of membranes (PPROM). @*Methods@#This was a retrospective cohort study involving 168 singleton pregnant women with PPROM. AF obtained via amniocentesis was cultured and assayed for interleukin (IL)-6 to define IAI and for IL-8 to compare with AF biomarkers. Plasma samples were collected at the time of amniocentesis, and C-reactive protein (CRP) levels in serum were compared with plasma biomarkers. The stored plasma and AF samples were assayed for LBP, pentraxin 3 (PTX3), resistin, and IGFBP-3 by ELISA. @*Results@#Multivariate logistic regression analysis revealed that: 1) elevated plasma and AF levels of LBP were independently associated with increased risks of MIAC, IAI, and microbial-associated IAI; 2) elevated AF, but not plasma, PTX3, and resistin levels were independently associated with increased risks of MIAC, IAI, and microbial-associated IAI; 3) decreased IGFBP-3 levels in the plasma were independently associated with only IAI, whereas those in the AF were associated with only microbial-associated IAI. Among the tested biomarkers, AF PTX3 and resistin had the highest predictive performance for MIAC, IAI, and microbial-associated IAI (area under the curves [AUC] = 0.85–0.95), which is similar to the performance of AF IL-8. The AUCs of the plasma LBP and IGFBP-3 were similar to that of serum CRP with respect to IAI. @*Conclusion@#Maternal plasma LBP and IGFBP-3 are potential biomarkers for the non-invasive identification of IAI in women with PPROM, with a similar accuracy to the serum CRP level.AF LBP, PTX3, resistin, and IGFBP-3 may be involved in the intra-amniotic inflammatory responses in PPROM complicated by MIAC.

The Identification of Immune-Related Plasma Proteins Associated with Spontaneous Preterm Delivery and Intra-Amniotic Infection in Women with Premature Cervical Dilation or an Asymptomatic Short Cervix

BACKGROUND@#We aimed to investigate whether various immune-related plasma proteins, alone or in combination with conventional clinical risk factors, can predict spontaneous preterm delivery (SPTD) and intra-amniotic infection in women with premature cervical dilation or a short cervix (≤ 25 mm).@*METHODS@#This retrospective study included 80 asymptomatic women with premature cervical dilation (n = 50) or a short cervix (n = 30), who underwent amniocentesis at 17–29 weeks. Amniotic fluid (AF) was cultured, and maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and complements C3a and C5a, using enzyme-linked immunosorbent assay (ELISA) kits. The primary outcome measures were SPTD at < 32 weeks and positive AF cultures.@*RESULTS@#The plasma levels of IL-6, C3a, and C5a, but not of MMP-9 and TIMP-1, were significantly higher in women with SPTD at < 32 weeks than in those who delivered at ≥ 32 weeks. The women who delivered at < 32 weeks had more advanced cervical dilatation, and higher rates of antibiotic and tocolytic administration and were less likely to be given vaginal progesterone than those who delivered at ≥ 32 weeks. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma IL-6 and C3a levels, and cervical dilatation (area under the curve [AUC], 0.901). The AUC for this model was significantly greater than that for any single variable included in the predictive model. In the univariate analysis, plasma IL-6 level was the only significant predictor of intra-amniotic infection.@*CONCLUSION@#In women with premature cervical dilation or a short cervix, maternal plasma IL-6, C3a, and C5a levels could be useful non-invasive predictors of SPTD at < 32 weeks. A combination of these biomarkers and conventional clinical factors may clearly improve the predictability for SPTD, as compared with the biomarkers alone. An increased plasma level of IL-6 predicted intra-amniotic infection.

The Identification of Immune-Related Plasma Proteins Associated with Spontaneous Preterm Delivery and Intra-Amniotic Infection in Women with Premature Cervical Dilation or an Asymptomatic Short Cervix

BACKGROUND: We aimed to investigate whether various immune-related plasma proteins, alone or in combination with conventional clinical risk factors, can predict spontaneous preterm delivery (SPTD) and intra-amniotic infection in women with premature cervical dilation or a short cervix (≤ 25 mm).METHODS: This retrospective study included 80 asymptomatic women with premature cervical dilation (n = 50) or a short cervix (n = 30), who underwent amniocentesis at 17–29 weeks. Amniotic fluid (AF) was cultured, and maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and complements C3a and C5a, using enzyme-linked immunosorbent assay (ELISA) kits. The primary outcome measures were SPTD at < 32 weeks and positive AF cultures.RESULTS: The plasma levels of IL-6, C3a, and C5a, but not of MMP-9 and TIMP-1, were significantly higher in women with SPTD at < 32 weeks than in those who delivered at ≥ 32 weeks. The women who delivered at < 32 weeks had more advanced cervical dilatation, and higher rates of antibiotic and tocolytic administration and were less likely to be given vaginal progesterone than those who delivered at ≥ 32 weeks. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma IL-6 and C3a levels, and cervical dilatation (area under the curve [AUC], 0.901). The AUC for this model was significantly greater than that for any single variable included in the predictive model. In the univariate analysis, plasma IL-6 level was the only significant predictor of intra-amniotic infection.CONCLUSION: In women with premature cervical dilation or a short cervix, maternal plasma IL-6, C3a, and C5a levels could be useful non-invasive predictors of SPTD at < 32 weeks. A combination of these biomarkers and conventional clinical factors may clearly improve the predictability for SPTD, as compared with the biomarkers alone. An increased plasma level of IL-6 predicted intra-amniotic infection.

The Identification of Immune-Related Plasma Proteins Associated with Spontaneous Preterm Delivery and Intra-Amniotic Infection in Women with Premature Cervical Dilation or an Asymptomatic Short Cervix

BACKGROUND@#We aimed to investigate whether various immune-related plasma proteins, alone or in combination with conventional clinical risk factors, can predict spontaneous preterm delivery (SPTD) and intra-amniotic infection in women with premature cervical dilation or a short cervix (≤ 25 mm).@*METHODS@#This retrospective study included 80 asymptomatic women with premature cervical dilation (n = 50) or a short cervix (n = 30), who underwent amniocentesis at 17–29 weeks. Amniotic fluid (AF) was cultured, and maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and complements C3a and C5a, using enzyme-linked immunosorbent assay (ELISA) kits. The primary outcome measures were SPTD at < 32 weeks and positive AF cultures.@*RESULTS@#The plasma levels of IL-6, C3a, and C5a, but not of MMP-9 and TIMP-1, were significantly higher in women with SPTD at < 32 weeks than in those who delivered at ≥ 32 weeks. The women who delivered at < 32 weeks had more advanced cervical dilatation, and higher rates of antibiotic and tocolytic administration and were less likely to be given vaginal progesterone than those who delivered at ≥ 32 weeks. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma IL-6 and C3a levels, and cervical dilatation (area under the curve [AUC], 0.901). The AUC for this model was significantly greater than that for any single variable included in the predictive model. In the univariate analysis, plasma IL-6 level was the only significant predictor of intra-amniotic infection.@*CONCLUSION@#In women with premature cervical dilation or a short cervix, maternal plasma IL-6, C3a, and C5a levels could be useful non-invasive predictors of SPTD at < 32 weeks. A combination of these biomarkers and conventional clinical factors may clearly improve the predictability for SPTD, as compared with the biomarkers alone. An increased plasma level of IL-6 predicted intra-amniotic infection.

Complement C3a, But Not C5a, Levels in Amniotic Fluid Are Associated with Intra-amniotic Infection and/or Inflammation and Preterm Delivery in Women with Cervical Insufficiency or an Asymptomatic Short Cervix (≤ 25 mm)

BACKGROUND: We aimed to estimate whether elevated levels of complement C3a and C5a in amniotic fluid (AF) are independently associated with increased risks of intra-amniotic infection and/or inflammation (IAI) and spontaneous preterm delivery (SPTD) in women with cervical insufficiency or a short cervix (≤ 25 mm). METHODS: We conducted a retrospective cohort study of 96 consecutive women with cervical insufficiency (n = 62) or a short cervix (n = 34) at 17 to 27 weeks, and who underwent an amniocentesis. AF was cultured and analyzed for C3a and C5a by enzyme-linked immunosorbent assay kits. The primary outcome measures were IAI (defined as a positive AF culture and/or an elevated AF interleukin-6 level [≥ 7.6 ng/mL]) and SPTD at < 32 weeks. RESULTS: In multivariable analysis, AF level of C3a was the only variable significantly associated with IAI, whereas C5a level in AF and serum C-reactive protein level were not associated with IAI. Using SPTD at < 32 weeks as the outcome variable in logistic regression, elevated AF levels of C3a were associated with increased risk of SPTD at < 32 weeks after adjusting for other baseline confounders, whereas elevated AF levels of C5a were not. CONCLUSION: In women with cervical insufficiency or a short cervix, elevated AF level of C3a, but not C5a, is independently associated with increased risks of IAI and SPTD at < 32 weeks. These findings suggest that subclinical IAI or SPTD in the context of cervical insufficiency is related to activation of complement system in AF.

Amniotic Fluid Infection, Cytokine Levels, and Mortality and Adverse Pulmonary, Intestinal, and Neurologic Outcomes in Infants at 32 Weeks' Gestation or Less

To what extent the risks of neonatal morbidities are directly related to premature birth or to biological mechanisms of preterm birth remains uncertain. We aimed to examine the effect of exposure to amniotic fluid (AF) infection and elevated cytokine levels on the mortality and pulmonary, intestinal, and neurologic outcomes of preterm infants, and whether these associations persist after adjustment for gestational age at birth. This retrospective cohort study included 152 premature singleton infants who were born at ≤ 32 weeks. AF obtained by amniocentesis was cultured; and interleukin-6 (IL-6) and IL-8 levels in AF were determined. The primary outcome was adverse perinatal outcome defined as the presence of one or more of the followings: stillbirth, neonatal death, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage, and periventricular leukomalacia. Logistic regression analysis was adjusted for gestational age at birth and other potential confounders. In bivariate analyses, elevated AF IL-6 and IL-8 levels were significantly associated with adverse perinatal outcome. These results were not changed after adjusting for potential confounders, such as low Apgar scores, mechanical ventilation, and surfactant application. However, the independent effect of elevated cytokine levels in AF disappeared when additionally adjusted for low gestational age at birth; consequently, low gestational age remained strongly associated with the risk of adverse perinatal outcome. In conclusion, elevated levels of pro-inflammatory cytokines in AF are associated with increased risk of adverse perinatal outcomes, but this risk is not independent of low gestational age at birth. Culture-proven AF infection is not associated with this risk.

Maternal Characteristics, Short Mid-Trimester Cervical Length, and Preterm Delivery

We aimed to determine the maternal characteristics (demographics, an obstetric history, and prior cervical excisional procedure) associated with a short mid-trimester cervical length (CL, defined as a CL of ≤ 25 mm) and whether having a short cervix explains the association between these maternal characteristics and spontaneous preterm delivery (SPTD, defined as a delivery before 34 weeks). This is a single-center retrospective cohort study of 3,296 consecutive women with a singleton pregnancy who underwent routine CL measurement between 20 and 24 weeks. Data were collected on maternal age, weight, height, parity, obstetric history (nulliparity; a history of at least 1 SPTD; and at least 1 term birth and no preterm birth [low-risk history group]), and prior cervical excisional procedure. In the multivariate regression analysis, an obstetric history, prior cervical excisional procedure, and gestational age at measurement were the variables significantly associated with short CL. In contrast, maternal weight, height, age, and parity were not significantly associated with short CL. By using the likelihood of SPTD as an outcome variable, logistic regression indicated that short CL and obstetric history, but not prior cervical excisional procedure, were significantly associated with SPTD after adjustment for potential confounders. A history of SPTD and prior cervical excisional procedure were associated with an increased risk of a short mid-trimester CL. A history of SPTD, but not prior cervical excisional procedure, is associated with an increased risk of SPTD, independent of a short CL.

Non-Invasive Prediction of Histologic Chorioamnionitis in Women with Preterm Premature Rupture of Membranes

PURPOSE: To develop a model based on non-invasive clinical and ultrasonographic parameters for predicting the likelihood of subsequent histologic chorioamnionitis in women with preterm premature rupture of membranes (PPROM) and to determine whether the inclusion of invasive test results improves the predictive value of the model. MATERIALS AND METHODS: This retrospective cohort study included 146 consecutive women presenting with PPROM (20-33 weeks). Transvaginal ultrasonographic assessment of cervical length was performed. Maternal serum C-reactive protein (CRP) levels and white blood cell (WBC) counts were measured after amniocentesis. Amniotic fluid (AF) obtained by amniocentesis was cultured, and interleukin-6 (IL-6) levels and WBC counts were determined. The primary outcome measure was histologic chorioamnionitis. RESULTS: Risk scores based on serum CRP concentrations and gestational age (model 1) were calculated for each patient. The model was shown to have adequate goodness of fit and an area under the receiver operating characteristic curve (AUC) of 0.742. When including AF test results (e.g., AF IL-6 levels) in model 1, serum CRP concentrations were found to be insignificant, and thus, were excluded from model 2, comprising AF IL-6 levels and gestational age. No significant difference in AUC was found between models 1 and 2. CONCLUSION: For women with PPROM, the newly developed model incorporating non-invasive parameters (serum CRP and gestational age) was moderately predictive of histologic chorioamnionitis. The inclusion of invasive test results added no predictive information to the model in this setting.

Practice patterns in the management of threatened preterm labor in Korea: A multicenter retrospective study

OBJECTIVE: This study aimed to examine clinical practice patterns in the management of pregnant women admitted with threatened preterm labor (TPL) in Korea. METHODS: Data from women admitted with a diagnosis of TPL were collected from 22 hospitals. TPL was defined as regular uterine contractions with or without other symptoms such as pelvic pressure, backache, increased vaginal discharge, menstrual-like cramps, bleeding/show and cervical changes. Data on general patient information, clinical characteristics at admission, use of tocolytics, antibiotics, and corticosteroids, and pregnancy outcomes were collected using an online data collections system. RESULTS: A total of 947 women with TPL were enrolled. First-line tocolysis was administered to 822 (86.8%) patients. As a first-line tocolysis, beta-agonists were used most frequently (510/822, 62.0%), followed by magnesium sulfate (183/822, 22.3%), calcium channel blockers (91/822, 11.1%), and atosiban (38/822, 4.6%). Of the 822 women with first-line tocolysis, second-line tocolysis were required in 364 (44.3%). Of 364 with second-line, 199 had third-line tocolysis (37.4%). Antibiotics were administered to 29.9% of patients (284/947) with single (215, 22.7%), dual (26, 2.7%), and triple combinations (43, 4.5%). Corticosteroids were administered to 420 (44.4%) patients. Betamethasone was administered to 298 patients (71.0%), and dexamethasone was administered to 122 patients (29.0%). CONCLUSION: Practice patterns in the management of TPL in Korea were quite various. It is needed to develop standardized practice guidelines for TPL management.

Ocular Findings in Children with Single Umbilical Artery: A Case Series of 14 Children

PURPOSE: Single umbilical artery (SUA) is the most common malformation of the umbilical cord. However, there have been no studies on the ocular findings in SUA, except for one case report. This study aimed to investigate the ocular findings in children with SUA. METHODS: Fourteen children (eight boys and six girls) with SUA were evaluated retrospectively. All children underwent a complete ophthalmologic examination. RESULTS: The prevalence of abnormal ocular findings in children was up to 42.9%. Refractive errors are detected in four eyes (14.3%): myopia > or =-1.50 diopters (D) in one eye (3.6%) and hyperopia > or =+2.00 D in three eyes (10.7%). Epiblepharon was found in three children (21.4%), and strabismus was detected in one child (7.1%). CONCLUSIONS: Approximately half of the children with SUA showed abnormal ocular findings, therefore, our case series highlight the need for a comprehensive ocular examination and larger prospective research studies in young patients with SUA.

A Case of Progressive Ductal Constriction in a Fetus

The ductus arteriosus is a normal and essential structure in fetal circulation. Since the introduction of fetal echocardiography, there have been reports of ductal constriction, many of which were related to maternal use of some medications. However, there have been some reports of idiopathic ductal constriction, which usually present in later gestation. Recently we experienced a case, which initially showed an S-shaped ductus with mild narrowing at 23 weeks and 27 weeks gestation and developed severe ductal constriction at 33 weeks. Soon after birth, ductus was searched for but no ductus was found in 2-D and color images. The neonate required mechanical ventilation with supplemental oxygen for 3 days. All echocardiographic abnormalities were normalized in 7 months. We report progressive ductal constriction in an S-shaped ductus and emphasize the importance of continuous follow up extending to the third trimester and even immediately after birth.

A Case of Progressive Ductal Constriction in a Fetus

The ductus arteriosus is a normal and essential structure in fetal circulation. Since the introduction of fetal echocardiography, there have been reports of ductal constriction, many of which were related to maternal use of some medications. However, there have been some reports of idiopathic ductal constriction, which usually present in later gestation. Recently we experienced a case, which initially showed an S-shaped ductus with mild narrowing at 23 weeks and 27 weeks gestation and developed severe ductal constriction at 33 weeks. Soon after birth, ductus was searched for but no ductus was found in 2-D and color images. The neonate required mechanical ventilation with supplemental oxygen for 3 days. All echocardiographic abnormalities were normalized in 7 months. We report progressive ductal constriction in an S-shaped ductus and emphasize the importance of continuous follow up extending to the third trimester and even immediately after birth.

Intra-Amniotic Infection/Inflammation as a Risk Factor for Subsequent Ruptured Membranes after Clinically Indicated Amniocentesis in Preterm Labor

The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI) was associated with subsequent ruptured membranes in women with preterm labor and intact membranes who had a clinically indicated amniocentesis. This retrospective cohort study included 237 consecutive women with preterm labor (20-34.6 weeks) who underwent amniocentesis. The clinical and laboratory parameters evaluated included demographic variables, gestational age, C-reactive protein (CRP) and amniotic fluid (AF) white blood cell, interleukin-6 (IL-6) and culture results. IAI was defined as a positive AF culture and/or an elevated AF IL-6 level (>2.6 ng/mL). The primary outcome was ruptured membranes in the absence of active labor occurring within 48 hours of amniocentesis. Preterm premature rupture of membranes subsequently developed in 10 (4.2%) women within 48 hr of amniocentesis. Multivariate analysis demonstrated that only IAI was independently associated with the ruptured membranes occurring within 48 hr of amniocentesis. In the predictive model based on variables assessed before amniocentesis, only CRP level was retained. IAI is an independent risk factor for subsequent ruptured membranes after clinically indicated amniocentesis in preterm labor. Prior to amniocentesis, measurement of serum CRP level can provide a risk assessment for the subsequent development of ruptured membranes after the procedure.

Relationship between Maternal Serum C-Reactive Protein, Funisitis and Early-Onset Neonatal Sepsis

The aim of this study was to determine whether maternal serum C-reactive protein (CRP) is of value in predicting funisitis and early-onset neonatal sepsis (EONS) in women with preterm labor or preterm premature rupture of membranes (PROM). This retrospective cohort study included 306 consecutive women with preterm labor or preterm PROM who delivered preterm singleton neonates (23-35 weeks gestation) within 72 hr of CRP measurement. The CRP level was measured with a highly sensitive immunoassay. The sensitivity, specificity, positive predictive value, and negative predictive value of an elevated serum CRP level (> or = 8 mg/L) were 74.1%, 67.5%, 32.8%, and 92.4% for funisitis, and 67.7%, 63.3%, 17.2%, and 94.6% for EONS, respectively. Logistic regression analysis demonstrated that elevated levels of serum CRP were significantly associated with funisitis and EONS, even after adjusting gestational age. The maternal serum CRP level obtained up to 72 hr before delivery is an independent predictor of funisitis and EONS in women with preterm labor or preterm PROM. A low serum CRP level (< 8 mg/L) has good negative predictive value in excluding funisitis and EONS, and may therefore be used as a non-invasive adjunct to clinical judgment to identify low-risk patients.

Non-invasive prediction of clinical infection in women with preterm labor / 대한산부인과학회지

OBJECTIVE: To develop a model based on non-invasive variables to predict the probability of subsequent maternal and/or neonatal clinical infection in women admitted to hospital for preterm labor with intact membranes. METHODS: Transvaginal ultrasound for measurement of cervical length was performed and maternal blood was collected for the determination of white blood cell (WBC) count at admission in 165 consecutive women with preterm labor (between 20.0 and 35.0 weeks). Clinical infection was defined as the presence of clinical chorioamnionitis at delivery or early onset neonatal sepsis. Receiver operating characteristic (ROC) curves and logistic regression analysis were used for statistical analyses. RESULTS: The prevalence of clinical infection was 5% (8/165). Women who developed clinical infection had a significantly lower median gestational age at admission, a lower shorter median cervical length, and a higher median WBC count as compared to those who did not develop clinical infection. Logistic regression analysis was performed and a final model was chosen, which included maternal blood WBC, cervical length, and gestational age as the best predictors of clinical infection. A risk score was calculated containing these 3 variables for each patient. The model was shown to have an adequate goodness of fit (P=0.202), and the area under the ROC curve was 0.822, indicating reasonably good discrimination. CONCLUSION: In women admitted to hospital for preterm labor with intact membranes, the risk for the subsequent maternal and/or neonatal clinical infection can be predicted non-invasively with a risk score based on cervical length at admission, maternal blood WBC, and gestational age.

Clinical and sonographic predictors for successful labor induction in preterm women / 대한산부인과학회지

OBJECTIVE: To identify the clinical and sonographic parameters which predict the likelihood of successful labor induction in preterm women. METHODS: This prospective observational study enrolled 103 consecutive preterm women (<37 weeks gestation) with singleton gestations scheduled for induction of labor. Transvaginal ultrasound for measurement of the cervical length was performed and the Bishop score was determined by digital examination. The parameters studied were gestational age at induction, parity, maternal age, Bishop score, sonographic cervical length, and current body mass index (BMI). Univariate and multivariate statistical methods were used for data analysis. RESULTS: Successful induction of labor occurred in 45 (44%) of women. Multiple logistic regression analysis identified parity, maternal BMI, and gestational age at induction as the independent predictors of successful labor induction in preterm women, although gestational age did not reach statistical significance (P=0.056). However, maternal age, sonographic cervical length, and Bishop score did not provide independent contribution to success of induction. CONCLUSION: In preterm women undergoing induction of labor parity, maternal BMI, and gestational age at induction were independent parameters in predicting successful induction of labor. However, sonographic cervical length and Bishop score had poor predictive values for success of labor induction.

Reference range for the sonographically estimated fetal weights in twin gestations / 대한산부인과학회지

OBJECTIVE: The purpose of this study was to establish the reference range for the sonographically estimated fetal weights (EFW) in twin gestations at 26 to 38 weeks' gestation. METHODS: This is a retrospective study of EFW that were obtained from electronic medical records of live births of all twins delivered between June 2003 through August 2007 at Seoul National University Bundang hospital. EFW was calculated using the mathematical model of Hadlock and only one measurement from each twin was used. Linear regression and Kolmogorov-Smirnov test were used for statistical analysis. RESULTS: Three hundred and forty-three twin pregnancies (686 fetuses) were included in this study. Reference range for EFW in twin gestations was presented as mean, standard deviation and percentiles. Scatterplots of EFW against gestational age (GA) were created with regression line of best fit and a linear growth function was observed between GA and EFW between 26 and 38 weeks' gestation (EFW=161.807 X GA - 3349.735 (r2=0.861, p<0.001). CONCLUSIONS: We established the reference range for EFW in twin gestations at 26 to 38 weeks' gestation. These results can be used as reference guidelines in the assessment of fetal growth restriction in Korean twin pregnancies.

A prospective longitudinal study of normal reference ranges for the length of fetal limb bones by ultrasound examination / 대한산부인과학회지

OBJECTIVE: To establish the reference ranges for the length of fetal limb bones (femur, tibia, fibula, humerus, ulna, radius, foot) at 12 to 38 weeks' gestation. METHODS: The candidates of this prospective longitudinal study were 43 consecutive women with uncomplicated singleton gestations who initially had antenatal care from the first trimester of pregnancy and follow-up regularly. We performed serial measurements of each limb bone and foot bone length by ultrasound examination every 4 weeks until 28 weeks, and then by 2 weeks until 36 weeks, and weekly thereafter. RESULTS: A total of 2,633 and 321 of fetal limb and foot bone lengths were measured. The reference ranges for the length of limb bones and foot length were presented as mean, 95% confidence interval of the means and in percentile. CONCLUSIONS: Our study results are represented as percentile tables for each of the limb bone length. These results can be provided as standardized data of the fetal limb bone length to distinguish from skeletal dysplasia and may well be suggested as the reference guideline for normal fetal limb bone length in Korea.

Relationship between Twin-to-twin Delivery Interval and Umbilical Artery Acid-base Status in the Second Twin

The purpose of this study was to determine the effect of twin-to-twin delivery interval on umbilical artery acid-base status of the second twin at birth. This was a retrospective cohort study of all live-born twins with measured acid-base status in umbilical arterial blood who were delivered after 34 weeks' gestation from June 2003 to February 2006. Twins with any maternal or fetal complications were excluded. Subjects were divided into two groups based on the mode of delivery of the first twin: normal cephalic vaginal deliveries (n=40) or cesarean deliveries (n=67). The inter-twin differences in umbilical arterial blood pH, PCO2, PO2, and base excess in twin newborns born vaginally were significantly greater than the corresponding differences in those born by cesarean section. A significant positive correlation was found between twin-to-twin delivery interval and inter-twin difference in umbilical arterial blood pH in twin newborns born vaginally. The umbilical arterial blood pH of the second twin was less than 7.0 in 14% (2/14) in cases delivered more than 20 min after the first twin. The umbilical arterial blood gas status of the second twin worsened with increasing twin-to-twin delivery interval, and pathologic fetal acidemia (pH<7.0) might develop in the second twin when the twin-to-twin delivery interval was greater than 20 min.

Cervical Length and the Risk of Microbial Invasion of the Amniotic Cavity in Women with Preterm Premature Rupture of Membranes

The aims of this study were to determine whether sonographically measured cervical length is of value in the identification of microbial invasion of the amniotic cavity in women with preterm premature rupture of membranes (PPROM) and to compare its performance with maternal blood C-reactive protein (CRP), white blood cell count (WBC), and amniotic fluid (AF) WBC. This prospective observational study enrolled 50 singleton pregnancies with PPROM. Transvaginal ultrasound for measurement of cervical length was performed and maternal blood was collected for the determination of CRP and WBC at the time of amniocentesis. AF obtained by amniocentesis was cultured and WBC determined. The prevalence of a positive amniotic fluid culture was 26% (13/50). Patients with positive amniotic fluid cultures had a significantly shorter median cervical length and higher median CRP, WBC, and AF WBC than did those with negative cultures. Multiple logistic regression indicated that only cervical length had a significant relationship with the log odds of a positive AF culture. Transvaginal sonographic measurement of cervical length is valuable in the identification of microbial invasion of amniotic cavity in women with PPROM. Cervical length performs better than AF WBC, maternal blood CRP, and WBC in the identification of a positive amniotic fluid culture.