Placental and maternal serum activin A in spontaneous and induced labor in late-term pregnancy.

PURPOSE: Feto-placental unit represents an important source of activin A, a member of transforming growth factors-ß involved in the mechanisms of labor. No evidences are available on activin A in pregnancies beyond 41 weeks of gestation, where induction of labor is often required. The present study aimed to evaluate activin A maternal serum levels and placental mRNA expression in term and late-term pregnancy, with spontaneous or induced labor, and its possible role to predict the response to labor induction. METHODS: Maternal serum samples and placental specimens were collected from women with singleton pregnancy admitted for either term spontaneous labor (n = 23) or induction of labor for late-term pregnancy (n = 41), to evaluate activin A serum levels and placental mRNA expression. Univariate and multivariate analyses on activin A serum levels, maternal clinical parameters, and cervical length were conducted in women undergoing induction of labor. RESULTS: Maternal serum activin A levels and placental activin A mRNA expression in late-term pregnancies were significantly higher than at term. Late-term pregnancies who did not respond to induction of labor showed significantly lower levels of activin A compared to responders. The combination of serum activin A and cervical length achieved a sensitivity of 100% and a specificity of 93.55% for the prediction of successful induction. CONCLUSION: Late-term pregnancy is characterized by hyperexpression of placental activin A and increased maternal activin A secretion. By combining maternal serum activin A levels with cervical length, a good predictive model for the response to induction of labor was elaborated.

Total and differential leukocyte count percentiles in healthy singleton term women during the first stage of labor.

AIMS: To establish leukocyte count and differential percentiles in healthy singleton term laboring women during spontaneous normal vaginal labor following an uncomplicated pregnancy. METHODS: An analysis of the records of all women (n = 762) who delivered at our delivery ward during a 2-month period was performed. After exclusion for cesarean delivery, induction of labor, pregnancy complications, preterm labor, multiple pregnancy, fever on admission, and lack of full blood count on admission, 365 parturient women during the 1st stage of labor were included in the final analysis. The total and differential leukocyte counts were determined by standard procedure by an automated cell counter. RESULTS: The leukocyte count range on admission to the delivery ward during the 1st stage of labor in healthy parturient women was between 4.4 × and 21.7 × 10(3)/µl and the 99th percentile limit was 20.06 × 10(3)/µl. The total leukocyte count was not influenced by cervical dilatation, ruptured membranes, or the presence and regularity of uterine contractions. CONCLUSION: An observed leukocyte count within the 99th percentile limit (20.06 × 10(3)/µl) in an otherwise normal parturient woman is reassuring in the absence of other clinical evidence.

Serum lactate dehydrogenase profile as a retrospective indicator of uterine preparedness for labor: a prospective, observational study.

BACKGROUND: Lactate dehydrogenase (LDH) isoenzymes are required for adenosine triphosphate production, with each of five different isoenzymes having varying proficiencies in anaerobic versus aerobic environments. With advancing pregnancy, the isoenzyme profile in uterine muscle shifts toward a more anaerobic profile, speculatively to facilitate uterine efficiency during periods of low oxygen that accompany labor contractions. Profile shifting may even occur throughout labor. Maternal serum LDH levels between 24-48 hours following delivery predominantly originate from uterine muscle, reflecting the enzymatic state of the myometrium during labor. Our purpose was to describe serum LDH isoenzymes 24-30 hours post-delivery to determine if cervical dilation rates following labor admission were associated with a particular LDH profile. We also compared differences in post-delivery LDH isoenzyme profiles between women admitted in pre-active versus established active labor. METHODS: Low-risk, nulliparous women with spontaneous labor onset were sampled (n = 91). Maternal serum LDH was measured at labor admission and 24-30 hours post-vaginal delivery. Rates of cervical dilation during the first four hours after admission were also measured. Spearman's rho coefficients were used for association testing and t tests evaluated for group and paired-sample differences. RESULTS: More efficient dilation following admission was associated with decreased LDH1 (p = 0.029) and increased LDH3 and LDH4 (p = 0.017 and p = 0.017, respectively) in the post-delivery period. Women admitted in established active labor had higher relative serum levels of LDH3 (t = 2.373; p = 0.023) and LDH4 (t = 2.268; p = 0.029) and lower levels of LDH1 (t = 2.073; p = 0.045) and LDH5 (t = 2.041; p = 0.048) when compared to women admitted in pre-active labor.Despite having similar dilatations at admission (3.4 ± 0.5 and 3.7 ± 0.6 cm, respectively), women admitted in pre-active labor had longer in-hospital labor durations (12.1 ± 4.3 vs. 5.3 ± 1.4 hours; p < 0.001) and were more likely to receive oxytocin augmentation (95.5% vs. 34.8%; p < 0.001). CONCLUSIONS: More efficient cervical dilation following labor admission is associated with a more anaerobic maternal serum LDH profile in the post-delivery period. Since LDH profile shifting may occur throughout labor, watchful patience rather than intervention in earlier labor may allow LDH shifting within the uterus to more fully manifest. This may improve uterine efficiency during labor and decrease rates of oxytocin augmentation, thereby improving birth safety.

C-reactive protein levels at pre-/post-indicated cervical cerclage predict very preterm birth.

AIMS: To investigate the relation between serum levels of C-reactive protein (CRP) at pre-/post-cerclage points and preterm birth at <33 weeks of gestation in women with indicated cervical cerclage (CC). METHODS: Fifty-eight women with CC indicated for a short or soft cervix, but no visible or protruding fetal membranes into the vagina, between 17 and 26 weeks of gestation, were reviewed. Serum CRP levels were examined three times: just before cerclage, and on day 1 and day 2 post-cerclage. RESULTS: Serum CRP levels on day 1 and day 2, but not just before cerclage, predicted the occurrence of very preterm birth. In women with cervical dilatation of <3.0 cm, serum CRP levels on post-cerclage day 1 were associated with the increase of very preterm birth [CRP ≥1.5 mg/dL vs. <1.5 mg/dL: 4/5 (80%) vs. 8/31 (26%), P=0.033]. In women with cervical dilatation of <3.0 cm, serum CRP ≥3.0 mg/dL on post-cerclage day 2 was also associated with the increase of very preterm birth. CONCLUSION: In women with indicated CC between 17 and 26 weeks of gestation, increased levels of serum CRP on post-cerclage day 1 or 2 might be ominous signs for very preterm birth.

Changes in intrapartum maternal placental growth factor levels in pregnancies complicated by fetal compromise at term.

BACKGROUND: Intrapartum fetal compromise (IFC) may result from the gradual decline in placental function during labour and can precipitate adverse neonatal outcomes. Placental growth factor (PlGF) is a biomarker of placental function. This study aims to investigate maternal PlGF levels and adverse perinatal outcomes in term labour. METHODS: Prospective observational study (Mater Mothers' Hospital, Brisbane). Eligibility: 37+0- 42+0 weeks gestation, singleton, cephalic, non-anomalous pregnancies. Cases of pre-eclampsia and fetal growth restriction were excluded. Maternal PlGF was sampled at the onset of the first stage of labour (1st PlGF) and again at the second stage (2nd PlGF). RESULTS: Sixty-three participants met inclusion criteria. Women requiring operative delivery (n = 11) for IFC had lower 1st PlGF (90.8 vs. 111.8 pg/ml) and 2nd PlGF (65.8 vs. 83.7 pg/ml) compared to the no-IFC cohort (n = 52). PlGF levels decreased significantly during labour in both the IFC (90.8 vs. 65.8 pg/ml, p = 0.021) and no-IFC (111.8 v 83.7, p < 0.001) cohorts, although the decline in PlGF levels was greater in the IFC cohort (-41.8% vs. -23.4%, p = 0.385). Maternal PlGF levels were significantly lower in those with an abnormal fetal heart rate pattern, cord arterial pH < 7.2, nursery admission and composite adverse neonatal outcome (CANO). PlGF decline was not correlated to duration of labour but was influenced by nulliparity and induced labour. CONCLUSIONS: Maternal PlGF levels are lower in pregnancies complicated by IFC and CANO, and declines more sharply during labour compared to the no-IFC cohort. The utility of PlGF as a predictor of IFC should be further investigated with clinical trials.

Tissue polypeptide specific antigen and soluble Fas during normal pregnancy and early life.

BACKGROUND: Intrauterine fetal development is characterized by increased rates of proliferation and apoptosis, while both these processes may be attenuated post-natally. AIM: Tissue polypeptide specific antigen and sFas serum concentrations were determined during pregnancy and post-natally, in order to evaluate their alterations during these crucial periods. MATERIALS AND METHODS: Forty-seven healthy pregnant women, their full-term newborns and 35 healthy adults (controls) were included in the study. Markers were measured: (a) in maternal serum (MS), during the 1st, 2nd, 3rd trimester and at the 1st stage of labor; (b) in the umbilical cord (UC), during the 2nd stage of labor; (c) in neonatal serum in the 1st (IN) and 5th (5N) day after birth; and (d) in controls. RESULTS: The serum TPS concentrations in MS increased significantly with gestational age, being higher in the 3rd trimester and labor, than those in controls (p < 0.001). TPS values were significantly lower in the UC, compared to those in MS (p < 0.001), while they were markedly elevated in IN, compared to MS and UC (p < 0.001), and subsequently decreased in 5N (p < 0.001), remaining higher, than those in the controls (p < 0.001). Serum sFas concentrations in the MS depended significantly on gestational age (p < 0.001), being significantly lower in the first trimester, than those in the second (p < 0.003), the third (p < 0.03), in labor and controls (p < 0.005). sFas concentrations in the UC were significantly lower than in MS and controls (p < 0.001), while they increased significantly in 5N samples (p < 0.01). CONCLUSION: Our results demonstrate: (a) a higher apoptosis rate in the first trimester of pregnancy, possibly affecting maternal immuno-tolerance, followed by a down-regulation during the post-natal period; (b) a progressively increased proliferation from the first trimester to parturition, reflecting the fetal and placental growth and development, that seems to be thereafter moderated.

Fear, pain and stress hormones during childbirth.

AIMS: To investigate the course of fear, pain and stress hormones during labor, and the associations between fear, pain, stress hormones and duration of labor in nulliparous women with and without epidural analgesia (EDA). METHOD: One day during gestation weeks 37-39, urinary and salivary samples were collected to measure catecholamines and cortisol. Hourly during labor, the participants answered the Delivery Fear Scale and a pain intensity scale, and urinary and salivary samples were collected to measure stress hormones. RESULTS: The course of fear, pain and stress hormones differed throughout labor in women with and without EDA. Pain and cortisol increased throughout labor in women without EDA. Women who received EDA had more fear, but not more pain, before the administration of the EDA than women who did not receive EDA. Pain, fear and catecholamines decreased when women received EDA, but fear and pain increased again later in labor. Fear and pain correlated, as well as levels of fear in the different phases of labor. During phase one of labor epinephrine and duration of the phase were negatively correlated. CONCLUSION: The course of fear, pain and concentrations of stress hormones differed, highly influenced by the administration of EDA. Fear and pain correlated more pronounced than stress hormones and fear, pain and duration of labor.

Correlation between maternal plasma homocysteine and zinc levels in preeclamptic women.

Women with preeclampsia have been shown to have elevated blood levels of the metabolite homocysteine, and alterations in blood levels of zinc and copper have also been reported. This study measured plasma levels of zinc, copper, and homocysteine in women with preeclampsia and in women with healthy, normotensive pregnancies. For the patients with preeclampsia compared with controls, significantly higher mean plasma levels were found of homocysteine (16.39 vs 9.45 nmol/mL; p

[Reference values range of the fetal oxygen saturation and its dispersal during labor without cardiotocographic evidence for fetal distress].

UNLABELLED: The objective of this study is to establish the reference values range of the fetal oxygen saturation during the first and the second period of labor and their dispersal according to the extent of cervical dillatation in cases with normal FHR--absence of fetal hypoxia and asphyxia of the newborn. MATERIAL AND METHODS: This is a prospective study which involves 94 women with normal FHR. All of the newborns are with umbilical artery pH values greater than 7.15 and 5 min Apgar score greater than 7; there was no necessity for any reanimation procedures, assisted ventilation or intensive care treatment. The fetal oxygen saturation (SpO2) is monitored by fetal pulseoxymeter Nellcor N 400, fetal sensors FS - 14. Cardiotocographic monitoring is carried out simultaneously. Blood is obtained from the fetal scalp during labor for blood gas and pH analysis, and umbilical artery pH as well as the Apgar score of the newborn are determined. RESULTS: The average monitoring time during the first period of labor is 107.19+/-29.49 min. with reliability of the recordings 86.54+/-6.10%. The average monitoring time for the second period of labor is 36.72+/-8.31 min. with reliability of the recordings 75.42 +/-9.61%. The mean SpO2 values are 48.71+/-5.52% during the first period and 47.30+/-4.62% during the second period of labor. The reference SpO2 values ranging between the 25-th and 75-th percentile in fetuses with normal FHR are 46-52 % for the first and 44-50 % for the second period. The results for fetal SpO2 during the different stages of cervical dillatation are as follows: for 4-5 cm - 49.49+/-5.12%, for 6-7 cm - 48.76+/-5.42%, for 8-9 cm - 48.39+/-5.49%. CONCLUSIONS: The fetal SpO2 dispersal during cervical dillatation of 4-5, 6-7 and 8-9cm accordingly demonstrates a nonsignificant decrease of SpO2 for the different groups (p>0.05). The fetal SpO2 dispersal between the first and the second period of labor also demonstrates decrease of SpO2 values and shows a minor statistically significant difference (p < 0.05 - Repeated measures ANOVA), which is considered to be within the normal range and does not reflect on the newborn's well-being.

Potential roles for gonadal steroids and insulin-like growth factor I during final cervical ripening.

OBJECTIVE: To determine whether gonadal steroids and insulin-like growth factor I influence the final cervical remodeling during parturition. METHODS: Cervical biopsies were obtained transvaginally before labor (n = 10) and after spontaneous cervical ripening and vaginal delivery (n = 20). Levels of estrogen and progesterone receptors, their messenger RNAs, insulin-like growth factor I messenger RNA, and serum estradiol and progesterone were measured. Collagen and proteoglycan concentrations and compositions were measured to estimate the degree of cervical ripeness. RESULTS: The concentrations of estrogen and progesterone receptors decreased in comparison with the clinically unripe cervix before labor. The median estrogen receptor concentration (range) decreased from 10 (2-18) to 4.5 (2-14) fmol/mg protein (P < .01), and the progesterone receptor concentration from 105.5 (32-153) to 74 (30-115) fmol/mg protein (P < .05), whereas their messenger RNA levels were unchanged. The insulin-like growth factor I messenger RNA concentration declined from 16.1 (8.4-20.4) at term to 8.9 (1.5-18.5) amol/microgram DNA after parturition (P < .01). The collagen solubility by pepsin increased, but not significantly, and the collagen concentration was unchanged. The concentration of small proteoglycans, mainly decorin, decreased from 1.59 (1.20-1.97) to 0.84 (0.24-1.41) micrograms/mg wet weight (P < .001), and the concentration of versican increased, but not significantly (P = .07). CONCLUSION: Concentrations of estrogen and progesterone receptors and insulin-like growth factor I messenger RNA were decreased significantly after spontaneous cervical ripening in comparison to levels before labor. These changes coincided with a tendency toward increased collagen solubility and a decline in concentration of small proteoglycans, which probably alters collagen organization, thus allowing for cervical softening and dilation. These observations suggest that gonadal steroids influence the final cervical remodeling during parturition, an influence perhaps mediated by insulin-like growth factor I.

Effects of intrathecal sufentanil on plasma oxytocin and cortisol concentrations in women during the first stage of labor.

BACKGROUND AND OBJECTIVES: Intrathecal sufentanil provides analgesia comparable to epidural bupivacaine for the first stage of labor. Both epidural local anesthetics and intrathecal opioid reduce some parameters of the neuroendocrine response to labor pain and the reflex release of oxytocin in animals. In humans, epidural local anesthetics only reduce the spurt release of oxytocin. This study compared the effect of intrathecal sufentanil and epidural bupivacaine administration on the plasma concentration of oxytocin and cortisol in women with labor pain during the first stage of labor. METHODS: Thirty healthy parturients requesting analgesia were enrolled in this randomized and open-label study. Each patient was in spontaneous labor at greater than 5 cm cervical dilatation. Using a combined spinal and epidural technique, patients received either intrathecal sufentanil 10 microg (SUF = intrathecal sufentanil group) or epidural plain bupivacaine 0.25%, 12 mL (BUPIV = epidural bupivacaine group). Analgesia was assessed using a visual analog scale, and blood samples for oxytocin and cortisol plasma concentration measurements were collected immediately before analgesia and 15, 30, 60, and 90 minutes after induction of the analgesia. Plasma cortisol and oxytocin concentrations were determined by specific radioimmunoassay. The values were expressed as mean +/- SEM. RESULTS: Intrathecal sufentanil provided faster and more complete analgesia within 15 and 30 minutes of its administration, compared with epidural bupivacaine. Plasma oxytocin concentrations were similar in the 2 groups before analgesia (7.24 +/- 2.1 and 6.6 +/- 3.1 pg/mL SUF and BUPIV, respectively). It decreased significantly in the SUF and increased in the BUPIV after analgesic administration. Cortisol concentrations were elevated in both groups before analgesia (51.6 +/- 5.3 and 54.2 +/- 4.8 microg/dL SUF and BUPIV, respectively). Both analgesic treatments significantly decreased the plasma cortisol levels. CONCLUSIONS: Intrathecal sufentanil analgesia decreases plasma concentrations of oxytocin and cortisol in women with labor pain during the first stage of labor, but epidural bupivacaine only reduced the cortisol concentration.

Labor experience, maternal mood and cortisol and catecholamine levels in low-risk primiparous women.

This exploratory, prospective study was set up to determine the relationship between cortisol and catecholamine levels and labor experience and postpartum maternal mood. It was performed at the Coronation Hospital, which serves a low-income urban population in Johannesburg. Blood samples were taken from 189 low-risk primiparous women in active first stage of labor and analyzed for cortisol, norepinephrine, epinephrine and dopamine. The stress hormone levels were then correlated with maternal anxiety, depression and self-esteem scores, and changes associated with mothers' labor experience and pain. Patients who were distressed and required analgesia had higher cortisol levels. Those who described a more positive labor experience at 24 hours also had higher cortisol levels. There were no significant correlations between psychological test scores and stress hormone levels. Both labor pain at the time and a more positive recollected labor experience were associated with high cortisol levels. Cortisol and catecholamine levels in labor did not correlate with postpartum psychological test scores.

Maternal C-reactive protein and preterm labor.

Maternal C-reactive protein (CRP) was measured in 109 pregnant women: 34 who were in labor before 35 weeks, 25 who were in labor at term and 50 who were not in labor. CRP values were correlated with outcome of tocolysis and with gestational age. Among 34 women in preterm labor, a CRP of greater than of equal to 0.8 mg/dL had a sensitivity of 85% (17/20) and a value of 81% (17/21) in predicting delivery within one week. Ten of the 14 who delivered more than one week following tocolysis had a CRP less than 0.8 mg/dL (71% specificity). Maternal CRP of greater than or equal to 0.8 mg/dL identifies a subgroup of women in preterm labor at highest risk of preterm delivery.

Maternal serum cortisol and prolactin variations during labor.

Maternal serum cortisol (F) and prolactin (PRL) levels were measured during labor in 20 uncomplicated pregnancies. Four pregnant women were admitted with ruptured membranes (RM group) and 16 were admitted with intact membranes (IM group), ten with spontaneous onset of labor (SL group) and 10 with induced labor (IL group), five with a prolonged for duration labor (PL group) and 15 with a normal for duration labor (NL group). Before the inset of labor F levels were statistically higher (p less than 0.05) in the RM group (x = 975 ng/ml), than in the IM group (x = 664 ng/ml), and also in the SL group (x = 783 ng/ml), than in the IL group (x = 679 ng/ml). During labor, in all twenty pregnant women a marked rise of F (from x = 726 ng/ml before the onset of labor, to x = 911 ng/ml) and a marked fall of PRL (from x = 161 ng/ml to x = 122 ng/ml) were observed (p less than 0.05). In the PL group the F elevation and the PRL drop were more pronounced (p less than 0.001). After placental separation, PRL levels increased slightly while F values remained unchanged. These changes in hormone levels before and during labor could be attributed to the emotional and physical stress of labor.

[Eutopic parturition: psychoprophylaxis or extradural analgesia. Influence on the endocrine response]. / Parto eutócico: psicoprofilaxis o analgesia extradural. Influencia sobre la respuesta endocrina.

Prolactin, ACTH, cortisol and HGH levels have been studied on 30 pregnant women in three different periods: during the labour, at the delivery and 24 hours later. They were divided into 3 groups depending on the analgesia: I) no analgesia (n = 10); II) psychoprophylaxis (n = 10), and III) extradural analgesia (n = 10). Prolactin levels increased during delivery and 24 hours later. A significant increase of ACTH levels (p less than 0.01) was observed during the delivery in the 3 groups even though they were under hasal values 24 hours later. Cortisol increased 38% (p less than 0.01) and 52% (p less than 0.02) in II and III groups, respectively during the delivery. No difference was found with HGH. Our results suggest that endocrine response modified by labour and delivery doesn't change with different analgesia techniques.

[Usefulness of the examination of fetal blood oxygen saturation (FSpO2) and fetal heart rate (FHR) as a prognostic factor of the newborn outcome]. / Ocena porównawcza plodowej pulsoksymetrii oraz komputerowej kardiotokografii w prognozowaniu pourodzeniowego stanu noworodka.

OBJECTIVES: Cardiotocography has become the standard for fetal monitoring in labor. False-positive findings during electronic fetal heart rate monitoring may were not associated with neonatal acidemia. Because of the poor specificity of fetal heart rate monitoring in predicting fetal distress, new methods are being investigated as a way to improve the accuracy of assessing the infant's condition during labor. DESIGN: The aim of this study was to determinate the efficiency of fetal blood oxygen saturation (FSpO2) and computer analysis of the fetal heart rate (Co-CTG) in the late 1-st stage of labor as a prognostic factor of newborn acidemia. MATERIALS AND METHODS: Total 62 subjects were studied. During labors and deliveries fetal oxygen saturation was continuously recorded, with use of Nellecor N-400 fetal pulse oximeter and continous CTG were performed by Hewlett Packard 50A. Transdermal fetal oxygen saturation measurements and CTG results obtained during the labors was analyzed using MONAKO system (ITAM Zabrze). The results were compared with the values of pH and base deficit in the umbilical artery measured just after delivery. RESULTS: The sensitivity, specificity, negative, positive predictive values and Youden factor based on FHR and FSpO2, for prognosis of neonatal acidosis were: 65%, 80%, 16%, 97.5% 60% and 0.135 respectively FHR; and 100%, 60%, 100%, 96.8% and 0.968 respectively FSpO2. CONCLUSIONS: 1. The examination of fetal blood oxygen saturation in the labor is a useful prognostic factor of the newborn outcome. 2. The best predictive value for intrapartum fetal asphyxia with metabolic acidosis was found when fetal pulse oximetry is added to cardiotocography.

Follistatin serum concentrations during full-term labour in women--significant differences between spontaneous and induced labour.

Follistatin has been isolated from human placenta and has been identified in human foetal membranes and fluids. Serum follistatin levels in women rise during pregnancy particularly near term. In this study, we examined the effect of induction and stage of labour on maternal plasma concentrations of follistatin. Women who gave birth after a normal pregnancy were retrospectively divided into three groups: those who went in labour spontaneously (n = 33), needed induction by amniotomy and IV oxytocin (n = 18) or underwent planned caesarean section (n = 10). Serum was collected at 38-40 weeks of gestation, periodically through labour with a vaginal examination and once within 36 h postpartum and assayed for oestradiol, progesterone, prolactin and C-reactive protein. Follistatin was measured using a rabbit antiserum (#204) raised against purified 35 kDa bovine follistatin. Human recombinant follistatin was used as both standard and tracer. Concentrations of follistatin at 38-40 weeks of gestation were significantly different between groups. Those who had a spontaneous labour had concentrations higher than those who were induced. Similarly, those who were induced had concentrations higher than those who underwent a caesarean. In the spontaneous group, follistatin rose during labour, peaking at 57.9 +/- 5.48 ng/ml at > 3 cm of cervical dilation, and after delivery follistatin decreased to 26.16 +/- 3.4 ng/ml at 24 h post-delivery. In induced patients follistatin continued increasing to peak following delivery at 26.9 +/- 3.0 ng/ml and decreased at > 3 h post-delivery. Follistatin concentrations in caesarean section patients at 24 h post-surgery (18.53 +/- 3.74 ng/ml) were not different from that before the surgery and were comparable with the other two groups. Follistatin is clearly implicated in the onset of labour; however, further studies with a larger cohort of women are necessary to determine the nature of its role.

Protein C, protein S, and thrombomodulin in amniotic fluid. A preliminary study.

OBJECTIVES: The main components of protein C anticoagulant system are protein C (PC), protein S (PS) and thrombomodulin (TM); the system plays a protective role in pregnancy, mainly because it prevents the utero-placental circulation from local thrombosis. It is unknown whether the protein C anticoagulant pathway exists in amniotic fluid. The aim of the present study is to find out whether these three components are present in amniotic fluid. STUDY DESIGN: The study group consisted of 50 parturients with an uneventful pregnancy and birth and 25 non-pregnant controls. Amniotic fluid and blood were sampled at the end of the 1st stage of labor. PC, PS and TM were measured by immunoenzymatic method. RESULTS: All the samples of amniotic fluid contained measurable amounts of antigens of PC, PS and TM, although their concentrations were significantly lower than in the mother's blood: (i) The concentration of PC in amniotic fluid was 6.24+/-3.50% and PS 2.40+/-1.64%, while in the mothers' plasma it was 138.26+/-12.38% and 93.15+/-13.24%, respectively (P<0.0001). (ii) TM concentration in amniotic fluid constituted 63.92% of the concentration in the mother's blood (2.71+/-1.21 ng/mL vs. 4.24+/-0.88 ng/mL, P<0.001). CONCLUSION: Protein C, protein S and thrombomodulin are physiological constituents of the amniotic fluid. As their concentrations are low, it is reasonable to assume that they cannot counterbalance the procoagulant activity of amniotic fluid.