Hyo Suk Seong

The frequency of microbial invasion of the amniotic cavity and histologic chorioamnionitis in women at term with intact membranes in the presence or absence of labor

OBJECTIVE The amniotic cavity is normally sterile for bacteria. However, experimental evidence indicates that regular uterine contractions exert a suction-like effect whereby vaginal fluid ascends into the uterine cavity with contractions (demonstrated by sonohysterography contrast media). Consequently, this study was conducted to determine whether the presence and progress of labor are associated with an increased risk of microbial invasion of the amniotic cavity (MIAC), intraamniotic inflammation, and histologic chorioamnionitis in women with term pregnancies with intact membranes. STUDY DESIGN Amniotic fluid (AF) was obtained from term singleton pregnant women with intact membranes at the time of cesarean delivery. AF was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and white blood cell (WBC) count was determined. Patients were divided into 3 groups according to the presence or absence of labor and the progress of labor. Nonparametric statistics were used for analysis. RESULTS Results included: (1) a total of 884 pregnant women were enrolled and divided into 3 groups: group 1, not in labor (n = 775); group 2, in early labor (cervical dilatation less than 4 cm) (n = 86); and group 3, in active labor (cervical dilatation 4 cm or greater) (n = 23); (2) the frequency of MIAC was 1% (6 of 775) in women not in labor, 3.5% (3 of 86) in patients with early labor, and 13% (3 of 23) in patients with active labor; and (3) the median AF WBC count and the frequency of histologic chorioamnionitis were also higher in the presence of labor than in the absence of labor. CONCLUSION We came to the following conclusions: (1) labor is associated with an increased risk of MIAC, a higher median AF WBC count, and histologic chorioamnionitis in term pregnancy with intact membranes; (2) the more advanced the cervical dilatation, the greater the risk of MIAC, a higher median AF WBC count, and histologic chorioamnionitis; and (3) in contrast, fetal inflammation (funisitis) did not increase with the presence of labor or as a function of cervical dilatation. We propose that labor predisposes to MIAC, a higher median AF WBC count, and histologic chorioamnionitis.

Amniotic fluid prostaglandin concentrations increase before the onset of spontaneous labor at term

Objectives. The role of prostaglandins (PGs) in the onset of human parturition has been controversial. Specifically, some investigators have proposed that PGs are the consequence rather than the cause of labor. An important question is whether or not amniotic fluid (AF) PG concentrations increase before the onset of labor in humans. Methods. The concentrations of PGs were determined in AF obtained from 167 singleton pregnant women with intact membranes. Patients were divided into four groups: (1) preterm not in labor (gestational age 15–36 weeks, n = 65); (2) term not in labor (n = 68); (3) spontaneous labor at term with cervical dilatation <4 cm (n = 25); (4) spontaneous labor at term with cervical dilatation ≥4 cm (n = 9). AF was obtained by transabdominal amniocentesis or collected at the time of cesarean delivery. All patients met the following criteria: (1) normal pregnancy outcome; (2) clear AF; (3) no significant medical or obstetric complications such as diabetes mellitus, preeclampsia, preterm birth, fetal growth restriction, or major congenital malformations; and (4) no significant neonatal complications. The concentrations of PGE2 and PGF2a in AF were determined by enzyme-linked immunosorbent assay (ELISA). Non-parametric analysis was performed. Results. (1) AF PG concentrations remained unchanged with advancing gestation until 36 weeks of gestation; (2) however, an abrupt increase in AF PG concentrations was observed before the onset of labor at term; (3) among cases without labor at term, the median AF PGF2a concentration increased with advancing gestation; (4) the presence of labor and the degree of cervical dilatation were significantly associated with a higher concentration of PGF2a. Conclusions. An abrupt increase in AF PG concentrations (25-fold for PGF2a) occurs before the onset of spontaneous labor at term in humans; these observations suggest that PGs increase prior to the onset of labor and contradict the claim that an increase in PG concentrations is the consequence of labor.

Identification of Proteomic Biomarkers of Preeclampsia in Amniotic Fluid Using SELDI-TOF Mass Spectrometry

Objective: To identify proteomic biomarkers in amniotic fluid (AF) that can distinguish preeclampsia (PE) from chronic hypertension (CHTN) and normotensive controls (CTR). Methods: AF from women with PE, CHTN, and CTR were subjected to proteomic analysis by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Results: Proteomic profiling of AF identified 2 biomarkers: peak X (17399.11 Da), which distinguished PE from CTR, and peak Y (28023.34 Da), which distinguished PE and CHTN from CTR. High performance liquid chromatography fractions containing the biomarkers were subjected to sodium dodecyl sulfate—polyacrylamide gel electrophoresis and in-gel tryptic digestion. The biomarkers were matched to proapolipoprotein A-I (peak Y) and a functionally obscure peptide, SBBI42 (peak X). Western blot analysis confirmed that AF from PE and CHTN had higher proapolipoprotein A-I levels than CTR. Conclusion: Proteomic analysis of AF can distinguish PE from CHTN and CTR. The discriminatory proteins were identified as proapolipoprotein A-I and SBBI42.

Evidence to support that spontaneous preterm labor is adaptive in nature: Neonatal RDS is more common in "indicated" than in "spontaneous" preterm birth

Abstract Objectives: The onset of preterm labor has been proposed to have survival value and to be adaptive in nature. This hypothesis would predict that induced preterm birth may be associated with higher rates of complications than spontaneous preterm birth. The purpose of this study was to determine if there is a difference in the frequency of neonatal respiratory distress syndrome (RDS), the most common neonatal complication, according to the etiology of preterm birth (e.g., preterm labor [PTL], preterm PROM, or pregnancies which ended because of maternal-fetal indications). Study design: The relationship between the occurrence of RDS and the obstetrical circumstances leading to preterm birth was examined in 257 consecutive singleton preterm births (gestational age: 24–32 weeks). Cases with major congenital anomalies were excluded. The study population was divided into two groups according to the cause of preterm birth: 1) preterm birth due to PTL with intact membranes or preterm PROM (spontaneous preterm birth group); and 2) preterm birth due to maternal or fetal indications (indicated preterm birth group). Results: 1) RDS was diagnosed in 47% of cases; 2) RDS was more common in patients with indicated preterm birth than in those with spontaneous preterm birth group (58.1% vs. 38.4%, P=0.002); 3) Patients with indicated preterm birth had a significantly higher mean gestational age at birth, but lower mean birth weight, lower rate of histological chorioamnionitis and higher rates of cesarean delivery, 5 min Apgar score of <7, and umbilical arterial blood pH of <7.15 than those with spontaneous preterm birth (P<0.05 for each); 4) Antenatal corticosteroids were used in 73.4% of cases with indicated preterm birth and in 76.9% of those with spontaneous preterm birth; 5) Multivariate analysis demonstrated that indicated preterm birth was associated with an increased risk of RDS after adjusting for confounding variables (OR=2.29, 95% CI 1.22–4.29). Conclusions: 1) The rate of RDS is greater following “indicated” rather than spontaneous preterm birth; 2) This observation supports the view that spontaneous preterm labor is adaptive in nature.

OP11.09: Uterine artery pulsatility index of hypertensive pregnancy: When is it normalized in puerperal period?

Objectives: To explore the association of uterine arteries (UA) waveform analysis with brachial artery flow-mediated dilation (BAFMD) in the prediction of preeclampsia in high-risk pregnancies. Methods: UA waveforms were recorded using Pulsed Doppler ultrasonography in 33 women at 22–24 weeks of gestation with high risk factors for preeclampsia (PE). Mean Pulsatility Index (PI) of both UA were registered. At the same time, brachial artery diameter was evaluated in basal and after stress conditions using Color Doppler; BAFMD was expressed as percent change in diameter from baseline. The onset of PE was divided in early (before 34 weeks of gestation) or late (after 34 weeks). Logistic regression models were developed, and their predictive ability assessed using ROC curves. Results: The prevalence of PE in the studied group was 24% (8/33), 5 early and 3 late-onset. Mean UA-PI and BAFMD values of cases without PE were lower, but not significant, than those developing PE (mean difference (MD): −0.39 (95% CI: −0.90–0.13) and −4.41% (95% CI: −16.1–7.3) respectively). Area under ROC curve for mean UA-PI was of 0.70 (95% CI: 0.41–0.99%), and for BAFMD of 0.59 (95% CI: 0.37–0.80). Logistic regression analysis was only significant for mean UA-PI (P = 0.034), and adding BAFMD did not improve the prediction. For early-onset PE, there were significant higher values in mean UA-PI (MD: 0.56 (95% CI: 0.19–0.94)), and higher BAFMD results but not significant (MD: 8.8% (95% CI: −4.6–22.2%)). Area under ROC curve for mean UA-PI was of 0.79 (95% CI: 0.44–1), and for BAFMD of 0.69 (95% CI: 0.46–0.91). Logistic regression analysis was only significant for mean UA-PI (P = 0.02), multivariate regression analysis combining UA-PI and BAFMD did not get better the prediction of early-onset PE. Conclusions: Although there is a trend of higher BAFMD in pregnancies with PE, the test in the second trimester did not improve the capacity for prediction of PE that provides the UA by itself.

P46.15: Clinical usefulness of fetal urine production in borderline oligohydramnios

Introduction: NO is a potent vasodilator and antiplatelet agent in the human cardiovascular system. Strong evidence for the role of NO deficiency in pathogenesis of gestational hypertensive disorders as well fetal growth restriction resulted in attempts to use exogenous form of this molecule in treatment of above-mentioned pregnancy complications. Material and methods: 202 women (mean age 27.96 ± 5.35 years) with pregnancies complicated by PIH and IUGR were randomly assigned to one of the following groups: 124 patients of study group, and 78 patients of control (placebo) group. Parallel to the standard antihypertensive therapy, patients from study group were administered orally 3g of L-arginine daily in three divided doses, whereas controls received placebo tablets. Fetal biometry, as well as Doppler blood flow velocimetry in uterine, umbilical and middle cerebral arteries was performed before, on the 1st day of therapy, in one week, and every two weeks until delivery. Result of measurements before treatment as well as the latest result before delivery were taken into considerations and compared. Results: After oral L-arginine supplementation, in the study group there was a reduced incidence of abnormal umbilical artery blood flow (5.36% vs. 24.24% in placebo group, P = 0.016) and uterine artery early – diastolic notching (for right uterine artery: 19.64% vs. 47.06% in placebo group, P = 0.008; for left uterine artery: 19.64% vs. 41.18% in placebo group, P = 0.03), whereas no alterations in middle cerebral blood flow and uterine artery PI were observed. Conclusions: Oral administration of L-arginine seems to be beneficial for fetoplacental circulation, but further studies are necessary to establish the influence of L-arginine on uterine artery blood flow. The fragmentary effect of L-arginine administration on uterine artery blood flow can be result of a too small dose of this substance used in study protocol.

P256: The value of prenatal ultrasonography to predict perinatal mortality of congenital diaphragmatic hernia

Results: No differences in lung volume based on coronal or transversal MR images were observed (r2 = 0.98; slope = 0.91 [0.82 − 1.01]). MR-FLV at termination was significantly related to lung volume at autopsy (r2 = 0.96, slope 1.27 [0.97 − 1.57], n = 6). MR-FLV in TO fetuses increased more rapidly with gestational age (21.0 [10.7 − 31.3] ml/day) than in CTRL (4.7 [1.7 − 7.7] ml/day). US-LRA increase was accelerated in TO (1.60 [1.3 − 1.9] cm2/day) with regard to CTRL (0.38 [0.23 − 0.53] cm2/day). US-LRA and MR-FLV were significantly correlated (r2 = 0.82). Conclusions: Fetal lung volume can be measured using MRI with moderate accuracy both from coronal and transverse sections. MRI and B-scan ultrasound are useful tools to monitor and quantify TO stimulated fetal lung growth in sheep fetuses.