Cytokine levels in amniotic fluid: a marker of preterm labor?

The aim of this study was to determine levels of Interleukin 6 (IL-6) in amniotic fluid at the beginning of the second trimester and to establish whether IL-6 can be used as a marker for premature birth as it would appear to be an important prenatal marker of chorionic inflammation. Thirty-three patients, between 16 and 19 weeks of gestation, who were undergoing amniocentesis to establish the presence or not of fetal genetic pathologies were enrolled into the study. Amniotic fluid (3 ml) was taken from each patient and used to perform enzyme-linked immunosorbent assays (ELISAs). The results were analyzed using the Mann-Whitney test and Pearson and Spearman coefficient. The patients were divided into three groups on the basis of the levels of IL-6 found: a) up to 450 pg/ml; b) between 450 and 900 pg/ml; c) over 900 pg/ml; These data were then evaluated alongside the date of parturition and the presence of any maternal or fetal pathologies. The results of our analyses, however, were inconclusive: levels of IL-6 were normal in patients presenting pathologies while obstetric pathologies were absent in patients with high levels of IL-6. In conclusion, this data would indicate that a different method or approach is required for the identification of a marker for premature birth.     

New onset of meconium during labor versus primary meconium-stained amniotic fluid – is there a difference in pregnancy outcome?

Abstract

Objective: To compare pregnancy outcome between deliveries complicated by new onset of meconium during labor following prior evidence of clear amniotic fluid and labors in which meconium was present to begin with.

Methods: A retrospective cohort study of all singleton term (≥37?+?0 weeks) deliveries complicated by intrapartum meconium-stained amniotic fluid in a tertiary referral medical center during the year 2012. Outcome was compared between deliveries with new onset of meconium during labor following prior evidence of clear amniotic fluid (secondary meconium group) and those in which meconium was already evident at the time of membranes rupture (primary meconium group).

Results: Of the 9167 deliveries during the study period, 694 were eligible for the study group. Of these, 537 were complicated by primary meconium and 157 by secondary meconium. Only secondary meconium, but not primary meconium, was independently associated with an increased risk of operative vaginal delivery (OVD) and adverse neonatal outcome. Pregnancies complicated by secondary meconium were independently associated with a higher rate of OVD (28.0% versus 11.4%, p?<?0.001), POP position of the fetal head (6.4% versus 2.6%, p?=?0.02), and adverse neonatal outcome (17.2% versus 8.9%, p?=?0.003).

Conclusion: Secondary meconium is associated with a higher rate of adverse obstetrical and neonatal outcome compared with primary meconium.     

Duration of labor induction in nulliparous women at term: how long is long enough?

We evaluated the relationship between duration of labor induction and successful vaginal delivery (VD) in nulliparous women at term. Nulliparous women with singleton pregnancies > or = 37 weeks who underwent labor induction at a single institution were studied. Exclusion criteria were nonvertex presentation, stillbirth, fetal chromosomal/structural abnormalities, spontaneous labor, and spontaneous rupture of membranes. VD rates and maternal/neonatal outcomes were evaluated and compared with respect to the duration from induction to delivery. Over the 1-year study period, 340 women met all criteria. Seventy-five percent achieved VD (n = 255), 40.6% of whom had rate of cervical dilation in active labor < 1.0 cm/hour. Women requiring cesarean delivery were more likely to have fetal acidemia, admission to the neonatal intensive care unit, chorioamnionitis, and endometritis. There was no association with prolonged induction to delivery intervals and adverse maternal/neonatal outcomes. In our population, only 5.7% of nulliparous women undergoing labor induction at term remain undelivered at 48 hours. Of women achieving VD, > 40% had rate of cervical dilation in active labor < 1.0 cm/hour.     

Induction of labor in grand multiparous women with previous cesarean delivery: how safe is this?

Objective: To compare the outcome of induced and spontaneous labor in grand multiparous women with one previous lower segment cesarean section (CS), so that the safety of labor induction could be assessed.

Methods: In 102 women (study group), labor was induced and the outcome was compared with 280 women (control group) who went into spontaneous labor. All 382 women were grand multiparous and had one previous CS.

Results: There were no significant difference in oxytocin augmentation, CS, scar dehiscence, fetal birth weight or apgar scores between groups. There was one neonatal death, two still births, one early neonatal death and one congenital malformation in the study group and this was not significant. There was no significant difference in vaginal birth in the study (80.9%) and the control group (83.8%).

Conclusion: In this moderate-sized study, induction of labor may be a safe option in grand multiparous women, if there is no absolute induction for repeating CS.     

Amino acids in amniotic fluid in the 15th–16th weeks of gestation and preterm labor

Objective. To investigate amino acids in amniotic fluid collected at the time of genetic amniocentesis.

Methods. We analyzed 128 fluids from the 15^th week of gestation and 53 from the 16^th week of gestation from normal pregnancies, and eight in the 15^th week and seven in the 16^th week from pregnancies that lead to preterm deliveries. We calculated the mean values for each week and the ratios between each pair of amino acids. The data for both groups (normal and preterm delivery) were compared.

Results. The most abundant amino acid in both groups was alanine. The comparisons of the groups showed significant differences for isoleucine in the 15^th gestational week (p < 0.05). Some amino acids had different evolutions between both gestational ages on comparing the normal group and preterm group. Eighteen ratios in the 15^th week showed significant differences (mainly in the ratios of arginine and taurine), and three in the 16^th week.

Conclusions. The amino acid profiles in amniotic fluid, particularly in the 15^th week of gestation, showed differences in the pregnancies that lead to preterm delivery.     

Changes in amniotic fluid concentration of thrombin–antithrombin III complexes in patients with preterm labor: Evidence of an increased thrombin generation

Objective.?Preterm labor is associated with excessive maternal thrombin generation, as evidenced by increased circulating thrombin–antithrombin (TAT) III complexes concentration. In addition to its hemostatic functions, thrombin has uterotonic properties that may participate in the mechanism leading to preterm birth in cases of intrauterine bleeding. Thrombin also has a proinflammatory role, and inflammation is associated with increased thrombin generation. The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI) is associated with increased amniotic fluid (AF) thrombin generation in women with preterm and term deliveries.

Study design.?This cross-sectional study included the following groups: (1) mid-trimester (n = 74); (2) term not in labor (n = 39); (3) term in labor (n = 25); (4) term in labor with IAI (n = 22); (5) spontaneous preterm labor (PTL) who delivered at term (n = 62); (6) PTL without IAI who delivered preterm (n = 59); (7) PTL with IAI (n = 71). The AF TAT III complexes concentration was measured by enzyme linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

Results.?(1) TAT III complexes were identified in all AF samples; (2) patients with PTL who delivered preterm, with and without IAI, had a higher median AF TAT III complexes concentration than those with an episode of PTL who delivered at term (p < 0.001, p = 0.03, respectively); (3) among patients with PTL without IAI, elevated AF TAT III complexes concentration were independently associated with a shorter amniocentesis-to-delivery interval (hazard ratio, 1.5; 95% CI, 1.07–2.1); (4) among patients at term, those with IAI had a higher median AF TAT III complexes concentration than those without IAI, whether in labor or not in labor (p = 0.02); (5) there was no significant difference between the median AF TAT III complexes concentration of patients at term with and without labor; (6) patients who had a mid-trimester amniocentesis had a lower median AF TAT III complexes concentration than that of patients at term not in labor (p < 0.001).

Conclusions.?We present herein a distinct difference in the pattern of intra-amniotic thrombin generation between term and preterm parturition. PTL leading to preterm delivery is associated with an increased intra-amniotic thrombin generation regardless of the presence of IAI. In contrast, term delivery is associated with an increased intra-amniotic thrombin generation only in patients with IAI.     

Are amniotic fluid alpha-fetoprotein levels influenced by the gender in twin pairs?

OBJECTIVES: To examine the assumption that amniotic fluid alpha-fetoprotein (AFAFP) levels are different in female and male twin fetuses. DESIGN: Amniotic fluid levels of AFP in pregnancies with female and male fetuses in gender-concordant and gender-discordant twins were compared. A t test of p < 0.05 was considered significant. MATERIAL AND METHODS: Between 1995 and 1999, 332 genetic amniocenteses on twin pregnancies were performed at Meir Hospital, Kfar Saba, and Rambam Hospital, Haifa, Israel. One hundred and sixty-six were concordant for gender (84 females and 82 males) while 166 pairs differed in their gender. The amniotic fluid AFP levels of each sac were measured using fluorescent immunoassay methods by an AutoDELFIA machine. RESULTS: The mean levels of AFAFP were lower in female twins compared to their male counterparts in same-gender twins (p = 0.07), although the difference was quite small. Nevertheless, there was no such difference between AFAFP of male versus female fetuses in gender-discordant twins. CONCLUSIONS: The levels of AFAFP were higher in the male twins of gender-concordant twins in comparison to female twins. No such difference was found between female versus male fetuses in gender-disconcordant twins.     

Bacteria and endotoxin in meconium-stained amniotic fluid at term: could intra-amniotic infection cause meconium passage?

Abstract

Background: Meconium-stained amniotic fluid (MSAF) is a common occurrence among women in spontaneous labor at term, and has been associated with adverse outcomes in both mother and neonate. MSAF is a risk factor for microbial invasion of the amniotic cavity (MIAC) and preterm birth among women with preterm labor and intact membranes. We now report the frequency of MIAC and the presence of bacterial endotoxin in the amniotic fluid of patients with MSAF at term.

Materials and methods: We conducted a cross-sectional study including women in presumed preterm labor because of uncertain dates who underwent amniocentesis, and were later determined to be at term (n?=?108). Patients were allocated into two groups: (1) MSAF (n?=?66) and (2) clear amniotic fluid (n?=?42). The presence of bacteria was determined by microbiologic techniques, and endotoxin was detected using the Limulus amebocyte lysate (LAL) gel clot assay. Statistical analyses were performed to test for normality and bivariate comparisons.

Results: Bacteria were more frequently present in patients with MSAF compared to those with clear amniotic fluid [19.6% (13/66) versus 4.7% (2/42); p?<?0.05]. The microorganisms were Gram-negative rods (n?=?7), Ureaplasma urealyticum (n?=?4), Gram-positive rods (n?=?2) and Mycoplasma hominis (n?=?1). The LAL gel clot assay was positive in 46.9% (31/66) of patients with MSAF, and in 4.7% (2/42) of those with clear amniotic fluid (p?<?0.001). After heat treatment, the frequency of a positive LAL gel clot assay remained higher in the MSAF group [18.1% (12/66) versus 2.3% (1/42), p?<?0.05]. Median amniotic fluid IL-6 concentration (ng/mL) was higher [1.3 (0.7–1.9) versus 0.6 (0.3–1.2), p?=?0.04], and median amniotic fluid glucose concentration (mg/dL) was lower [6 (0–8.9) versus 9 (7.4–12.6), p?<?0.001] in the MSAF group, than in those with clear amniotic fluid.

Conclusion: MSAF at term was associated with an increased incidence of MIAC. The index of suspicion for an infection-related process in postpartum women and their neonates should be increased in the presence of MSAF.     

HIV detection in amniotic fluid samples. Amniocentesis can be performed in HIV pregnant women?

OBJECTIVES: To assess amniotic fluid (AF) HIV contamination as a marker of intrauterine HIV infection and to evaluate amniocentesis as a risk factor for vertical HIV transmission when the mother was under antiretroviral treatment. STUDY DESIGN: Three hundred and sixty-six HIV pregnant women were included in the study. AF was obtained from three groups of patients: (a) genetic amniocentesis before 1997 (n=11); (b) amniocentesis a few days before the delivery day (n=18); and (c) AF collected on delivery (n=38). An univariate study was conducted to analyze amniocentesis as a risk factor of HIV transmission (groups a and b). Groups b and c were recruited after 1997; these patients were under combined antiretroviral treatment, they were studied to relate AF HIV contamination with fetal infection and maternal blood viral load at delivery (n=56). RESULTS: From 1984 to 1996, before antiretroviral therapy use in HIV pregnant women, transmission rate was 17%. In the group of patients who underwent genetic amniocentesis (group a) it was 30% (3/10) versus 16.2% (40/247) for patients without amniocentesis. Between 1997 and 2000 transmission rate was 3%. In group b it was 0% (0/18) when amniocentesis was done versus 3.7% (3/81) if no amniocentesis was done (no statistical differences). AF virus was undetectable in all samples (n=56) and no newborn infection was observed after the follow up. CONCLUSIONS: Amniotic fluid virus load was undetectable when maternal antiretroviral therapy was used, even if the virus was detectable in maternal blood samples. This finding raises the possibility to perform amniocentesis, when it is indicated, to provide the mother with an adequate antiretroviral treatment.     

Uterine electrical activity at labor: is there a correlation between labor stages?

Objective: To determine the association between the myometrial electrical activity in the active and second stages of labor at term using electrical uterine myography (EUM).

Methods: A prospective observational study of 47 singleton deliveries at term in a tertiary hospital. All women were assessed using noninvasive 9-channel surface electrodes of the EUM during labor. EUM index (EUMi) was calculated as the mean electrical activity during a 30?min monitoring period and expressed as microjouls (MJ). Mean EUMi of the active and second stages of labor were compared accordingly.

Results: Mean EUMi during the active phase was 3.53?±?0.43?MJ, whereas mean EUMi in the second stage was 3.66?±?0.48?MJ (p?=?0.02). Correlation analysis between mean EUMi of the active and second stages of labor produced r^2?=^?0.68 (p?r^2?=^?0.73, p?Conclusion: A positive correlation of myometrial electrical activity exists between active phase and second stage of labor. However, while EUMi was associated with the duration of the active phase, no correlation was found between EUMi and the duration of the second stage.     

Dye-dilution techniques using aminohippurate sodium: do they accurately reflect amniotic fluid volume?

Objective: To determine whether the dye-dilution technique using aminohippurate sodium accurately measures amniotic fluid volume. Methods: Singleton pregnancies with intact membranes undergoing a Cesarean delivery had their amniotic fluid volume assessed by the dye-dilution technique and direct measurement. Results: Fifteen women were prospectively assessed. Six patients had their amniocentesis on the delivery table and nine patients at 4-24 h prior to the Cesarean delivery. The six women undergoing an amniocentesis just before delivery had good concordance between the dye-determined and direct measurement of amniotic fluid volume (r = 0.99, p = < 0.001). Among the nine women with varying times from amniocentesis to direct measurement, the correlation was not significant (r = 0.36, p = 0.08). The percentage difference between the dye-determined and directly measured amniotic fluid volume was significantly smaller in the women undergoing amniocentesis just prior to delivery (7%) than in the women with varying times from amniocentesis to delivery (37%, p < 0.001). Conclusion: Dye-determined amniotic fluid volume accurately reflects actual amniotic fluid volume but the dye-determined concentrations, in vivo, may undergo rapid changes.     

Emergency contraception: how effective is it?

This paper explores the efficacy of emergency contraception methods, particularly the Yuzpe regimen and the IUD. The most commonly used Yuzpe regimen of combined oral contraceptive pills prevents 75% of expected pregnancies. The insertion of a copper IUD within 5 days of unprotected sexual intercourse prevents 99% of pregnancies. However, neither of these two methods is fully satisfactory for emergency contraception. In addition to the failure of the Yuzpe regimen to prevent approximately 25% of pregnancies, it can also cause some unpleasant side effects. On the other hand, the copper IUD, while certainly effective as a method of emergency contraception, has a certain number of limitations and disadvantages. First, it is usually not advised for women who do not have children, despite the fact that this population group comprises a larger proportion of those who seek emergency contraception. Second, the IUD is an inappropriate method for women at risk of developing sexually transmitted diseases unless an added barrier method is used. Third, its usage is generally not recommended for women with unclear pregnancy status, as it causes serious complications in women with established pregnancies.