Vaginal delivery in SARS-CoV-2-infected pregnant women in Northern Italy: a retrospective analysis.

OBJECTIVE: To report mode of delivery and immediate neonatal outcome in women infected with COVID-19. DESIGN: Retrospective study. SETTING: Twelve hospitals in northern Italy. PARTICIPANTS: Pregnant women with COVID-19-confirmed infection who delivered. EXPOSURE: COVID 19 infection in pregnancy. METHODS: SARS-CoV-2-infected women who were admitted and delivered from 1 to 20 March 2020 were eligible. Data were collected from the clinical records using a standardised questionnaire on maternal general characteristics, any medical or obstetric co-morbidity, course of pregnancy, clinical signs and symptoms, treatment of COVID 19 infection, mode of delivery, neonatal data and breastfeeding. MAIN OUTCOME AND MEASURES: Data on mode of delivery and neonatal outcome. RESULTS: In all, 42 women with COVID-19 delivered at the participating centres; 24 (57.1%, 95% CI 41.0-72.3) delivered vaginally. An elective caesarean section was performed in 18/42 (42.9%, 95% CI 27.7-59.0) cases: in eight cases the indication was unrelated to COVID-19 infection. Pneumonia was diagnosed in 19/42 (45.2%, 95% CI 29.8-61.3) cases: of these, 7/19 (36.8%, 95% CI 16.3-61.6) required oxygen support and 4/19 (21.1%, 95% CI 6.1-45.6) were admitted to a critical care unit. Two women with COVID-19 breastfed without a mask because infection was diagnosed in the postpartum period: their newborns tested positive for SARS-Cov-2 infection. In one case, a newborn had a positive test after a vaginal operative delivery. CONCLUSIONS: Although postpartum infection cannot be excluded with 100% certainty, these findings suggest that vaginal delivery is associated with a low risk of intrapartum SARS-Cov-2 transmission to the newborn. TWEETABLE ABSTRACT: This study suggests that vaginal delivery may be associated with a low risk of intrapartum SARS-Cov-2 transmission to the newborn.

Bedside diagnosis of two major clinical phenotypes of hypertensive disorders of pregnancy.

OBJECTIVE: To investigate the hypothesis that fetal abdominal circumference (AC) and uterine artery (UtA) Doppler pulsatility index (PI) could be used to select two homogeneous subgroups of women affected by hypertensive disorders of pregnancy (HDP), characterized by the coexistence of maternal hypertension with and without intrauterine growth restriction (IUGR). METHODS: This was a multicenter retrospective study of cases affected by HDP in whom fetal AC and UtA-PI had been measured at admission to fetomaternal medicine units. Maternal characteristics, pregnancy complications and outcome were recorded. These data allowed us to model the characteristics of fetal growth in cases affected by HDP, and to design composite indicators of risk factors for maternal metabolic syndrome and of severity for maternal functional organ damage. RESULTS: Measurements of fetal AC and UtA-PI allowed us to define a group of HDP cases with appropriate-for-gestational-age (AGA) fetuses (HDP-AGA), diagnosed by normal fetal AC and UtA-PI (n = 205), and a group of HDP cases with IUGR fetuses (HDP-IUGR), diagnosed by fetal AC < 5(th) centile and UtA-PI > 95(th) centile (n = 124). Curves fitted to the birth weights of these two groups were significantly different, but gestational age at admission for HDP (< 34 or ≥ 34 weeks) did not show an independent association with birth weight. When birth weight was expressed as a Z-score with respect to local reference charts, the average corresponded to the 6(th) and 48(th) centiles, respectively. The occurrence of HDP-AGA (as compared with HDP-IUGR) was significantly associated with risk factors for maternal metabolic syndrome (odds ratio, 2.79 (95% CI, 1.57-4.97)), independent of gestational age. The same risk factors yielded non-significant odds ratios for the development of late-onset (vs early-onset) HDP. Women with HDP-IUGR had worse clinical outcomes. CONCLUSIONS: This study provides new information based on simple prenatal bedside examinations that might help to differentiate HDP-IUGR from HDP-AGA fetuses. These groups are associated with different fetal growth patterns and risk factors, independent of gestational age at onset of the disease. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

A combination therapy to treat second-degree anti-Ro/La-related congenital heart block: a strategy to avoid stable third-degree heart block?

While mainly based on the use of fluorinated steroids, there is no standard management of anti-Ro/La-related congenital heart block (CHB). This is a report concerning two consecutive cases of anti-Ro/La-related second-degree block treated with betamethasone (4 mg/day), weekly plasmapheresis, and intravenous immunoglobulins (IVIGs; 1 g/kg) administered every 15 days, a therapy that was begun shortly after CHB was detected and continued until delivery. The newborns were also treated with IVIG (1 g/kg) soon after birth and continued fortnightly until the anti-Ro/La antibody levels became undetectable. In both cases second-degree AV block reverted to a stable sinus rhythm with a first-degree atrioventricular (AV) block. Moreover, there was no recurrence of CHB when therapy was suspended, as confirmed by a 29 month and an eight month follow-up, respectively.

Adjusted prophylactic doses of nadroparin plus low dose aspirin therapy in obstetric antiphospholipid syndrome. A prospective cohort management study.

OBJECTIVES: Current guidelines for the treatment of patients with obstetric antiphospholipid syndrome (APS) recommend low dose aspirin (LDA) and prophylactic doses of low molecular weight heparin (LMWH). Most clinicians use a fixed dosage of LMWH in pregnant APS women despite the fact that there are no clinical trials establishing that fixed doses are more efficacious than adjusted ones in preventing pregnancy complications. The efficacy and safety of adjusted single daily doses of LMWH (nadroparin) combined with LDA have thus been evaluated in 33 consecutive pregnancies in women with diagnosed obstetric APS. METHODS: LMWH doses were augmented as the pregnancies progressed and maternal/foetal weight increased. 70-80-90 U/Kg doses ranging between 3800 and 6650 U were administered daily during the first, second and third trimesters, respectively. LDA (100 mg/day) was also prescribed. RESULTS: Pregnancy outcome was successful in 97% of the patients studied, who delivered, between the 29th and 41st weeks of gestation (mean 37.4 ±2.1 SD), 32 infants with a mean birth weight of 3084 g ± 514 SD. One woman (3%) experienced a spontaneous abortion at the 8th week of gestation. CONCLUSIONS: The high live birth rate, the satisfactory mean gestational age and weight at birth and the absence of major pregnancy/neonatal-associated complications indicate that adjusted, once daily doses of LMWH together with LDA could be an efficacious treatment option for pregnant APS patients with no history of thrombosis.

Vaginal progesterone reduces the rate of preterm birth in women with a sonographic short cervix: a multicenter, randomized, double-blind, placebo-controlled trial.

OBJECTIVES: Women with a sonographic short cervix in the mid-trimester are at increased risk for preterm delivery. This study was undertaken to determine the efficacy and safety of using micronized vaginal progesterone gel to reduce the risk of preterm birth and associated neonatal complications in women with a sonographic short cervix. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled trial that enrolled asymptomatic women with a singleton pregnancy and a sonographic short cervix (10-20 mm) at 19 + 0 to 23 + 6 weeks of gestation. Women were allocated randomly to receive vaginal progesterone gel or placebo daily starting from 20 to 23 + 6 weeks until 36 + 6 weeks, rupture of membranes or delivery, whichever occurred first. Randomization sequence was stratified by center and history of a previous preterm birth. The primary endpoint was preterm birth before 33 weeks of gestation. Analysis was by intention to treat. RESULTS: Of 465 women randomized, seven were lost to follow-up and 458 (vaginal progesterone gel, n=235; placebo, n=223) were included in the analysis. Women allocated to receive vaginal progesterone had a lower rate of preterm birth before 33 weeks than did those allocated to placebo (8.9% (n=21) vs 16.1% (n=36); relative risk (RR), 0.55; 95% CI, 0.33-0.92; P=0.02). The effect remained significant after adjustment for covariables (adjusted RR, 0.52; 95% CI, 0.31-0.91; P=0.02). Vaginal progesterone was also associated with a significant reduction in the rate of preterm birth before 28 weeks (5.1% vs 10.3%; RR, 0.50; 95% CI, 0.25-0.97; P=0.04) and 35 weeks (14.5% vs 23.3%; RR, 0.62; 95% CI, 0.42-0.92; P=0.02), respiratory distress syndrome (3.0% vs 7.6%; RR, 0.39; 95% CI, 0.17-0.92; P=0.03), any neonatal morbidity or mortality event (7.7% vs 13.5%; RR, 0.57; 95% CI, 0.33-0.99; P=0.04) and birth weight < 1500 g (6.4% (15/234) vs 13.6% (30/220); RR, 0.47; 95% CI, 0.26-0.85; P=0.01). There were no differences in the incidence of treatment-related adverse events between the groups. CONCLUSIONS: The administration of vaginal progesterone gel to women with a sonographic short cervix in the mid-trimester is associated with a 45% reduction in the rate of preterm birth before 33 weeks of gestation and with improved neonatal outcome.

Laboratory and clinical features of pregnant women with antiphospholipid syndrome and neonatal outcome.

OBJECTIVE: To evaluate the relationship between the antiphospholipid profile and clinical characteristics of pregnant women with antiphospholipid syndrome (APS) and neonatal outcome. METHODS: We retrospectively considered 109 treated pregnancies of 93 patients with primary APS and reviewed the medical records of their 111 infants. Neonatal outcome was assessed using the following variables: weeks of gestational age at delivery, percentiles of birth weight, Apgar score at 5 minutes, need for cardiopulmonary resuscitation in the delivery room, time in the neonatal intensive care unit, infections, and other neonatal complications. Univariate statistical analysis was performed to evaluate the relationship between APS maternal features and neonatal outcome parameters. RESULTS: When maternal APS features and variables of infant outcome were analyzed, it was evident that lupus anticoagulant (LAC), triple antiphospholipid positivity, and history of vascular thrombosis were significantly associated with some parameters of a poor infant outcome. History of pregnancy morbidity alone was, instead, significantly correlated to the variables of favorable neonatal outcome. CONCLUSION: There seems to be more than one kind of pregnant woman with APS. Even when treated with a second-line therapy plan, mothers with LAC and/or triple antiphospholipid positivity and/or previous thromboembolism seem to have a high probability of poor neonatal outcome, whereas those with pregnancy morbidity alone, treated with conventional drugs, seem to have a high probability of favorable outcome.

Prediction of successful induction of labor at term: role of clinical history, digital examination, ultrasound assessment of the cervix, and fetal fibronectin assay.

OBJECTIVE: The purpose of this study was to evaluate whether biochemical (fetal fibronectin assay) or biophysical (cervical assessment by transvaginal ultrasound) tests may have more value than digital examination in predicting successful induction of labor at term. STUDY DESIGN: The study enrolled prospectively 134 women undergoing labor induction at term caused by several obstetric conditions. All participants submitted to digital examination, fetal fibronectin assay, and transvaginal ultrasound for measurement of the cervical length and detection of funneling. The performance of each test in predicting delivery within 24 hours of labor induction was evaluated. Cox multiple regression analysis was performed to identify, among clinical and laboratory tests, which variables were independently associated with the duration of the latent phase and with the total duration of induced labor. RESULTS: The likelihood ratios for positive results (predicting that delivery would occur within 24 hours) were 6.61 (95% CI, 1.7-25.8) for a positive obstetric history (previous vaginal delivery), 2.61 (95% CI, 1.6-4.3) for a "favorable" digital examination, 1.41 (95% CI, 0.9-2.2) for a positive fetal fibronectin test, 1.61 (95% CI, 0.9-3.0) for cervical length, and 2.20 (95% CI, 1.1-4.4) for the presence of funneling at transvaginal ultrasound. The likelihood ratios for negative results were 1.81 (1.3-2.5) for obstetric history, 4.34 (2.5-7.7) for digital examination, 1.41 (0.9-2.1) for fetal fibronectin, 1.29 (1.0-1.7) for cervical length, and 1.48 (1.1-2.0) for funneling. On multiple regression, the only variables independently associated with the duration of the latent phase and with the total duration of induced labor were obstetric history and digital examination. CONCLUSION: Only obstetric history and digital examination predicted accurately vaginal delivery within 24 hours and were independently associated with labor duration. Fetal fibronectin and ultrasound measurements failed to predict accurately the outcome of induced labor.

Neonates born to pre-eclamptic mothers have a higher percentage of natural killer cells (CD3-/CD56+16+) in umbilical cord blood than those without pre-eclampsia.

OBJECTIVE: Maternal endothelial dysfunction and intravascular inflammation have been implicated in the mechanisms of disease responsible for the clinical syndrome of pre-eclampsia. Recently, the activation of the innate limb of the immune response (neutrophils and monocytes) in the fetal circulation has been reported in neonates born to mothers with pre-eclampsia. Natural killer (NK) cells are identified morphologically as a subpopulation of lymphocytes, but functionally as one component of the innate immune system. NK cells participate in the control of viral or bacterial infection, regulation of hematopoiesis, production of cytokines and cytotoxicity of neoplastic cells. Accumulating evidence suggests that the innate system is required for mounting an adequate adaptive response. NK cells, originally defined as effector cells of the innate immune system, may also play a role as regulatory cells for the adaptive immune system. This study was designed to determine the proportion of the NK cell subset of lymphocytes in umbilical cord blood of neonates born to mothers with and without pre-eclampsia. METHODS: A cross-sectional study including neonates of mothers with (n = 48) and those without pre-eclampsia (control group) (n = 72) was conducted. Pre-eclampsia was diagnosed in the presence of hypertension and proteinuria. The control group consisted of neonates (premature and term) with no evidence of acute inflammation within the extraplacental membranes (chorioamnionitis). Umbilical cord blood was collected at the time of delivery, and assayed using monoclonal antibodies for selective cluster differentiation (CD) antigens in order to determine the proportion of NK cells as a percentage of total lymphocytes. The immunophenotypic characteristic was determined using flow cytometry, and NK cells were identified by positivity of CD16 and CD56 without CD3 (CD3-/CD56+16+). Log transformation of the percentage of NK cells was performed. Parametric statistics were used for analysis. Multiple regression analysis was utilized to examine the contribution of potentially confounding factors on the proportion of NK cells. A p value of < 0.05 was considered statistically significant. RESULTS: Neonates born to mothers with pre-eclampsia had a significantly higher percentage of NK cells (CD3-/CD56+16+) than those in the control group (pre-eclampsia, mean +/- SD 17 +/- 9% vs. control, mean +/- SD 12 +/- 7.5%; p = 0.001). Multiple regression analysis suggested that umbilical cord blood pH of < 7.2, labor with vaginal delivery and maternal pre-eclampsia were associated with an increased percentage of NK cells in umbilical cord blood. CONCLUSIONS: Pre-eclampsia is associated with a higher NK cell (CD3-/CD56+16+) subset of lymphocytes in umbilical cord blood than in the control group. This difference cannot be explained by fetal acidosis or the presence of labor.

Unexplained fetal death is associated with changes in the adaptive limb of the maternal immune response consistent with prior antigenic exposure.

OBJECTIVE: The causes of fetal death are largely unknown. CD4 T cells have been classified according to the expression of the CD45 isoforms into 'naive-like' T cells (CD45RA) and 'memory-like' T cells (CD45RO). An increase in the percentage of the CD45RO has been interpreted as indicating prior antigenic exposure of the host and, in newborns, evidence of infection. The purpose of this study was to determine whether unexplained fetal death was associated with a change in the proportion of 'naive-like' and 'memory-like T cells' in the maternal blood, as determined by the CD45 isoforms on the surface of CD4+ lymphocytes. STUDY DESIGN: A prospective study was conducted to compare the CD45 sub-population of lymphocytes in patients with intrauterine fetal death (n = 26) and normal pregnancy (n = 89). The percentages of CD45RA+, CD45RO+ and CD45RA+/CD45RO+ on CD4+ T lymphocytes were determined in maternal blood using flow cytometry and monoclonal antibodies. Results were reported as a percentage of CD4+ lymphocytes. Non-parametric statistics were used for analysis. A p value of < 0.05 was considered significant. RESULTS: Patients with intrauterine fetal death had a higher percentage of CD45RO+ CD4+ T lymphocytes than normal pregnant women (fetal death: median 57.7%, range 35.4-78.6 vs. normal pregnancy: median 49.9%, range 19.1-86.8; p = 0.004). Fetal death was associated with a lower median percentage of CD45RA+ CD4+ lymphocytes than in normal pregnant women (fetal death: median 32.3%, range 15.3-58.0 vs. normal pregnancy: median 40.2%, range 11.2-67.3; p = 0.01). There was no significant difference in the percentage of cells with dual expression (CD45RA+/CD45RO+) between the study groups. CONCLUSION: Prior exposure to microbial products (bacterial or viral) or other unidentified antigens may result in a shift of the sub-population of 'naive-like' T cells to 'memory-like' T cells in mothers with unexplained fetal death.

Maternal intravascular inflammation in preterm premature rupture of membranes.

OBJECTIVE: Intrauterine inflammation has been implicated in the mechanisms responsible for preterm premature rupture of membranes (PROM). However, it is unclear whether this inflammatory process remains localized to the uterus, at the site of membrane rupture, or extends to the maternal compartment. Flow cytometric analysis is a sensitive method to assess the presence and magnitude of in vivo inflammation. This study was conducted to determine whether preterm PROM is associated with changes in the phenotypic and metabolic characteristics of maternal granulocytes and monocytes consistent with the presence of maternal intravascular inflammation. STUDY DESIGN: A prospective cross-sectional study was performed including patients with preterm PROM (n = 43) and normal pregnancy (n = 51). Maternal intravascular inflammation was studied using flow cytometry. Maternal blood was assayed to determine granulocyte and monocyte phenotype using monoclonal antibodies, which included cluster differentiation (CD) markers CD11b, CD14, CD15, CD16, CD18, CD49d, CD62L, CD64, CD66b and human leukocyte antigen (HLA)-DR. The quantities of basal intracellular reactive oxygen species (iROS) and oxidative burst was assessed. Statistical analysis was conducted with the use of non-parametric methods. A p value < 0.01 was considered significant. RESULTS: Preterm PROM was associated with a significant increase in the median mean channel brightness (MCB) of CD11b, CD14, CD64 and CD66b on granulocytes and median MCB of CD11b on monocytes. The oxidative burst and the stimulation index in both cell types were higher in preterm PROM than in normal pregnancy (p < 0.01). CONCLUSION: Preterm PROM is associated with phenotypic and metabolic changes in circulating granulocytes and monocytes.

Phenotypic and metabolic characteristics of monocytes and granulocytes in normal pregnancy and maternal infection.

OBJECTIVE: Normal pregnancy has been proposed to be a state of physiologic activation of the innate limb of the immune response. Recent studies have concluded that normal pregnancy produces inflammatory changes in peripheral blood leukocytes akin to those of sepsis. This unexpected observation has implications that are critical to understanding the susceptibility of pregnant women to sepsis, the pathophysiology of preeclampsia, and the biology of normal pregnancy. This study was designed to examine the phenotypic and metabolic characteristics of monocytes and granulocytes in normal pregnancy and in pregnant patients with acute infection. STUDY DESIGN: A cross-sectional study was conducted that included nonpregnant women (n = 20), normal pregnant women (n = 57), and pregnant women with a positive blood culture and/or pyelonephritis (n = 16). Phenotypic and metabolic characteristics of monocytes and granulocytes were studied with the use of flow cytometry and monoclonal antibodies against surface markers (CD11b, CD14, CD15, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR). Intracellular reactive oxygen species were measured at basal conditions and after stimulation (oxidative burst). The stimulation index (ratio of intracellular reactive oxygen species after oxidative burst over basal state) was calculated. Nonparametric statistics were used. A probability value of <.01 was considered statistically significant. RESULTS: Granulocytes from normal pregnant women had a higher median mean channel brightness for CD14 and CD64, but lower median mean channel brightness for CD16 and HLA-DR than granulocytes of nonpregnant women. Granulocytes of patients with acute infection had a higher median mean channel brightness for CD64 and CD66b than granulocytes of normal pregnant women. Monocytes from patients with acute infection had a higher mean channel brightness for CD11b, CD16, CD18, CD49d, CD64, and CD66b than monocytes of normal pregnant women. Baseline intracellular reactive oxygen species, oxidative burst, and stimulation index values were significantly higher in the granulocytes and monocytes of normal pregnant women than in the granulocytes and monocytes of nonpregnant women. Similarly, baseline intracellular reactive oxygen species, oxidative burst, and stimulation index values were higher in women with acute infections than in normal pregnant women. CONCLUSION: Normal pregnancy was associated with phenotypic and metabolic changes of granulocytes and monocytes; pregnant women with acute infection had more marked phenotypic and metabolic changes of leukocytes than normal pregnant women. These qualitative differences indicate that the innate limb of the immune response is not maximally activated during normal pregnancy.

Phenotypic and metabolic characteristics of maternal monocytes and granulocytes in preterm labor with intact membranes.

OBJECTIVE: Experimental and clinical studies support a role for the fetus in the control of the onset of labor. Fetal systemic inflammation, but not a maternal inflammatory response, has been linked to the onset of preterm labor and delivery on the basis of the determination of inflammatory cytokines in fetal and maternal blood. We propose that parturition requires fetomaternal cooperation and that inflammation is an integral part of the parturitional process. This study used flow cytometry, a sensitive technique for the detection of intravascular inflammation, to assess whether maternal inflammation is present in preterm labor. STUDY DESIGN: A prospective cross-sectional study was performed including patients with preterm labor (n = 55) and women with normal pregnancy (n = 50). Intravascular inflammation was studied by using flow cytometry. Maternal blood was assayed to determine granulocyte and monocyte phenotype by using monoclonal antibodies, which included the following cluster of differentiation (CD) markers: CD11b, CD14, CD15, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. Oxidative burst and generation of basal intracellular oxygen radical species were assessed. Statistical analysis was conducted with the use of nonparametric methods. A P value of <.01 was considered statistically significant. RESULTS: Preterm labor was associated with a significant increase in the median mean channel brightness of CD11b, CD15, and CD66b on granulocytes and median mean channel brightness of CD11b and CD15 on monocytes. The ratio of oxidative burst over basal intracellular oxygen radical species in both granulocytes and monocytes was increased in preterm labor (P <. 01). CONCLUSION: Preterm labor with intact membranes is associated with phenotypic and metabolic changes of maternal granulocytes and monocytes.

Phenotypic and metabolic characteristics of monocytes and granulocytes in preeclampsia.

OBJECTIVE: The maternal syndrome of preeclampsia has recently been attributed to a systemic intravascular inflammatory response and endothelial cell activation and dysfunction. This novel hypothesis has considerable clinical and biological implications. This study was designed to determine whether women with preeclampsia have evidence of intravascular inflammation by examination of the phenotypic and metabolic activity of granulocytes and monocytes. STUDY DESIGN: A cross-sectional study was performed that included patients with preeclampsia (n = 31) and normal pregnancies (n = 58) matched for gestational age at blood draw. Intravascular inflammation was studied with use of flow cytometry. Peripheral venous blood was assayed to determine granulocyte and monocyte phenotype with the use of monoclonal antibodies for selective cluster differentiation (CD) antigens. The panel of antibodies included CD11b, CD14, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. The quantity of basal intracellular reactive oxygen species and oxidative burst was assessed. Results were reported as mean channel brightness or intensity of detected fluorescence. Analysis was conducted with nonparametric statistics. A P value <.01 was considered to be significant. RESULTS: Preeclampsia was associated with a significant increase in mean channel brightness for CD11b on granulocytes and monocytes but lower mean channel brightness for CD62L on granulocytes than those from women with normal pregnancy (P <.01 for each). Basal intracellular reactive oxygen species were increased in monocytes but not in granulocytes. The oxidative burst was higher in both cell types. CONCLUSION: Preeclampsia is associated with phenotypic and metabolic changes in granulocytes and monocytes.

Participation of the novel cytokine interleukin 18 in the host response to intra-amniotic infection.

OBJECTIVE: Interleukin 18 is a proinflammatory pleiotropic cytokine that has been implicated in the host defense against infection. This study was undertaken to determine whether interleukin 18 concentrations change in the maternal, fetal, and amniotic fluid compartments with labor (term and preterm) and microbial invasion of the amniotic cavity. STUDY DESIGN: Amniotic fluid was assayed for interleukin 18 in samples obtained from 285 patients in the following groups: (1) term not in labor (n = 22), in labor (n = 19), and with microbial invasion of the amniotic cavity (n = 16); (2) preterm labor who delivered at term (n = 38), who delivered preterm but without microbial invasion of the amniotic cavity (n = 41), and preterm labor with microbial invasion of the amniotic cavity (n = 24); (3) preterm premature rupture of membranes without microbial invasion of the amniotic cavity (n = 30) and with microbial invasion of the amniotic cavity (n = 34); (4) term premature rupture of membranes not in labor (n = 20) and term premature rupture of membranes in labor (n = 19); and (5) midtrimester (n = 22). In addition, cord and maternal plasma samples from women at term not in labor (n = 20) and in labor (n = 20) were assayed for interleukin 18. RESULTS: (1) Interleukin 18 was detectable in all amniotic fluid samples and maternal and umbilical cord blood samples. (2) Interleukin 18 concentrations increased with advancing gestational age (r = 0.47; P <.0001). (3) Microbial invasion of the amniotic cavity in either preterm or term parturition was associated with a significant increase in the amniotic fluid concentration of interleukin 18 (preterm labor without microbial invasion of the amniotic cavity: median, 14.95 pg/mL; range, 3.9-277.0 pg/mL; vs preterm labor with microbial invasion of the amniotic cavity: median, 20.75 pg/mL; range, 5.53-160.21 pg/mL; P <.02; term labor without microbial invasion of the amniotic cavity: median, 18.73 pg/mL; range, 5.09-95.44 pg/mL; vs term labor with microbial invasion of the amniotic cavity: median, 24.35 pg/mL; range, 10.07-144.42 pg/mL; P<.004). (4) Both term and preterm parturition were associated with a modest increase in amniotic fluid interleukin 18 concentrations, although this trend did not reach statistical significance. (5) Rupture of membranes at term was associated with a significant decrease in amniotic fluid interleukin 18 concentrations (intact membranes: median, 14.96 pg/mL; range, <3.89-26.07 pg/mL; vs rupture of membranes: median, 10.1 pg/mL; range, 4.29-21.44 pg/mL; P <.001). CONCLUSION: (1) Interleukin 18 is increased in cases of microbial invasion of the amniotic cavity. (2) Interleukin 18 is detectable in the amniotic, maternal, and fetal compartments. (3) We propose that this novel cytokine plays a role in the host defense against infection.

Evidence of in vivo differential bioavailability of the active forms of matrix metalloproteinases 9 and 2 in parturition, spontaneous rupture of membranes, and intra-amniotic infection.

OBJECTIVE: Matrix metalloproteinases (MMP-9 and MMP-2) have been implicated in the digestion of fetal membranes. The purpose of this study was to determine the amniotic fluid concentrations of active forms of MMP-2 and MMP-9 and to explore the participation of these enzymes in labor (term and preterm), rupture of membranes (term and preterm), and microbial invasion of the amniotic cavity. STUDY DESIGN: A cross-sectional study was conducted with 291 women in the following categories: (1) term not in labor, (2) term in labor, (3) preterm labor and intact membranes who delivered at term, (4) preterm labor who delivered preterm, (5) preterm labor with microbial invasion of the amniotic cavity, (6) preterm premature rupture of membranes without microbial invasion of the amniotic cavity, (7) preterm premature rupture of membranes with microbial invasion of the amniotic cavity, (8) term premature rupture of membranes not in labor, and (9) mid trimester. Active forms of MMP-2 and MMP-9 were measured by a novel assay that uses a substrate developed by protein engineering. RESULTS: (1) MMP-2 and MMP-9 were detected in 88% and 96% of amniotic fluid samples, respectively (255/291 and 279/291). (2) The concentrations of active forms of MMP-2 and MMP-9 changed with advancing gestational age. (3) Spontaneous term parturition was associated with a significant increase in the median concentration of the active forms of MMP-9 (P <.005) and a significant decrease in the median concentration of the active forms of MMP-2 (P <.003). (4) Preterm labor with intact membranes leading to preterm delivery in the absence of infection was associated with a significant increase in the median concentration of the active forms of MMP-9 (P <.005) but not of the active forms of MMP-2 (P =.2). (5) Rupture of membranes (either term or preterm) was associated with a significant increase in the concentration of the active forms of MMP-9 and with a significant decrease in the concentration of the active forms of MMP-2 (P <.005 for term and P <.03 and P <.003 for preterm, respectively). (6) Microbial invasion of the amniotic cavity in women with preterm premature rupture of membranes was also associated with a significant increase in the concentration of the active forms of MMP-9 (P <.03) and a decrease in the concentration of the active forms of MMP-2 (P <.05). (7) Microbial invasion of the amniotic cavity in patients with preterm labor was associated with a significant increase in the median concentration of the active forms of MMP-9 (P <.005) but not of the active forms of MMP-2 (P =.6). CONCLUSION: Spontaneous rupture of membranes (either term or preterm), parturition (either term or preterm), and microbial invasion of the amniotic cavity were associated with significant increases in the amniotic fluid concentration of the active forms of MMP-9. In contrast, the concentration of the active forms of MMP-2 either decreased or remained the same in these conditions. Our observations provide evidence for a novel regulation of gelatinolytic activity in vivo.

Lactoferrin in intrauterine infection, human parturition, and rupture of fetal membranes.

OBJECTIVE: Lactoferrin is an iron-binding protein with antimicrobial properties. This study was undertaken to determine whether amniotic fluid concentrations of this protein change with gestational age, infection, labor, and rupture of membranes. STUDY DESIGN: This cross-sectional study included women who underwent transabdominal amniocentesis (n = 268) in the following groups: (1) mid trimester of pregnancy; (2) preterm labor who delivered at term, preterm labor who delivered preterm with intra-amniotic infection, and preterm labor who delivered preterm without intra-amniotic infection; (3) preterm premature rupture of membranes in the presence or absence of intra-amniotic infection; (4) term with intact membranes not in labor, in labor, and in labor with intra-amniotic infection; and (5) premature rupture of membranes at term not in labor. In addition, lactoferrin concentrations were determined in maternal plasma and cord blood of patients at term not in labor. Lactoferrin concentration was measured with an immunoassay. RESULTS: (1) Lactoferrin was detectable in 85.4% (229/268) of amniotic fluid samples, not detectable in all fluid obtained in the mid trimester, and detectable in all maternal and cord plasma samples. (2) The concentration of lactoferrin increased with advancing gestational age (r = 0.68; P <.0001). (3) Intra-amniotic infection was associated with significant increases in amniotic fluid lactoferrin concentrations in patients with preterm labor (no intra-amniotic infection median, 1641.2 ng/mL; range, <1.24-35,090.0 ng/mL; vs intra-amniotic infection median, 3833.6 ng/mL; range, 746.0-47,020.0 ng/mL; P <.001), term labor (no intra-amniotic infection median, 2085.8 ng/mL; range, 425.0-23,230.0 ng/mL; vs intra-amniotic infection median, 5627.0 ng/mL; range, <1.24-19,220.0 ng/mL; P <. 001), and preterm premature rupture of membranes (no intra-amniotic infection median, 2190 ng/mL; range, <1.24-7456.1 ng/mL; vs intra-amniotic infection median, 3449.3 ng/mL; range, <1.24-83,600. 0; P <.01). (4) Spontaneous labor at term but not preterm was associated with a significant decrease in amniotic fluid lactoferrin concentration (P <.05). (5) Spontaneous term parturition was associated with a significant increase in umbilical cord plasma lactoferrin concentration (P <.005). CONCLUSION: (1) Intra-amniotic infection was consistently associated with dramatically increased concentrations of lactoferrin in amniotic fluid. (2) Term parturition was associated with a significant increase in lactoferrin concentration in the fetal compartment (umbilical cord blood) and a decrease in the amniotic compartment. We propose that lactoferrin is part of the repertoire of host defense mechanisms against intra-amniotic infection.

Evidence for the participation of interstitial collagenase (matrix metalloproteinase 1) in preterm premature rupture of membranes.

OBJECTIVE: Rupture of membranes is thought to result from the effects of physical forces in localized areas of the membranes weakened by the degradation of structural collagens. Matrix metalloproteinases are enzymes that degrade extracellular matrix components and have been implicated in membrane rupture. The objective of this study was to determine whether spontaneous rupture of membranes is associated with a change in the amniotic fluid concentration of interstitial collagenase (matrix metalloproteinase 1 [MMP-1]), a major collagenase. STUDY DESIGN: A cross-sectional study was conducted to determine MMP-1 concentrations in amniotic fluid from 353 women in the following categories: (1) term with intact membranes not in labor and in labor, (2) preterm labor who delivered at term, (3) preterm labor who delivered preterm without microbial invasion of the amniotic cavity, (4) preterm labor who delivered preterm with microbial invasion of the amniotic cavity, (5) preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, (6) term premature rupture of membranes not in labor and in labor, and (7) mid trimester of pregnancy. Microbial invasion of the amniotic cavity was determined by an amniotic fluid culture positive for microorganisms. MMP-1 concentrations in amniotic fluid were determined by means of sensitive and specific immunoassays. RESULTS: (1) MMP-1 was detectable in 81.3% of amniotic fluid samples (287/353), and its concentrations increased with advancing gestational age (r = 0.4; P <.001). (2) Preterm premature rupture of membranes was associated with a significant increase in the median amniotic fluid concentration of MMP-1 (P =.02). (3) Women with term premature rupture of membranes had a significantly lower amniotic fluid MMP-1 concentration than those with intact membranes at term not in labor (P <.001). (4) Microbial invasion of the amniotic cavity in patients in preterm labor with intact membranes and in patients with preterm premature rupture of membranes was also associated with significant increases in the median amniotic fluid MMP-1 concentrations (P <.05 and P <.01, respectively). (5) Patients with preterm premature rupture of membranes and microbial invasion of the amniotic cavity had a significantly higher median amniotic fluid MMP-1 concentration than those with intact membranes and microbial invasion of the amniotic cavity (P =.01). (6) Neither term nor preterm parturition was associated with changes in amniotic fluid MMP-1 concentrations (P =.6 and P =.3, respectively). CONCLUSION: (1) Collagenase 1 (MMP-1) is a physiologic constituent of amniotic fluid. (2) Preterm premature rupture of membranes (in both the presence and absence of infection) was associated with an increase in the amniotic fluid MMP-1 concentrations. (3) Neither term nor preterm parturition was associated with a significant increase in the amniotic fluid concentration of MMP-1.

Matrilysin (matrix metalloproteinase 7) in parturition, premature rupture of membranes, and intrauterine infection.

OBJECTIVE: Matrix metalloproteinases are enzymes capable of degrading extracellular matrix components. Matrilysin (matrix metalloproteinase 7), a novel member of this family, degrades fibronectin and proteoglycans. The objective of this study was to determine whether parturition (either term or preterm), premature rupture of the membranes, and microbial invasion of the amniotic cavity are associated with changes in the amniotic fluid concentration of matrilysin. STUDY DESIGN: A cross-sectional study was conducted with 275 women in the following categories: (1) second trimester, (2) term not in labor, (3) term in labor, (4) term with microbial invasion of the amniotic cavity, (5) preterm labor with intact membranes without microbial invasion of the amniotic cavity who delivered at term, (6) preterm labor without microbial invasion of the amniotic cavity who delivered preterm, (7) preterm labor with microbial invasion of the amniotic cavity, (8) preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, and (9) term premature rupture of membranes not in labor and without microbial invasion of the amniotic cavity. Matrilysin concentrations were measured with a sensitive specific immunoassay that was validated for amniotic fluid. RESULTS: Matrilysin was detectable in 97.4% (268/275) of the samples. The concentration of matrilysin increased with advancing gestational age (r = 0.8; P <.001). Parturition at term was not associated with a significant increase in amniotic fluid concentration of matrilysin. Preterm parturition in the absence of microbial invasion of the amniotic cavity was associated with a significant increase in amniotic fluid concentration of matrilysin (preterm labor with preterm delivery: median, 1.7 ng/mL; range, 0.45-21.6 mg/mL; vs preterm labor with term delivery: median, 1.2 ng/mL; range, 0.17-42. 1 ng/mL; P <.05). Premature rupture of membranes without microbial invasion of the amniotic cavity (either term or preterm) was not associated with a significant change in the amniotic fluid matrilysin concentration. Intra-amniotic infection was associated with a significant increase in amniotic fluid matrilysin among both patients with preterm labor and patients with preterm premature rupture of membranes (preterm labor with microbial invasion of the amniotic cavity: median, 3.2 ng/mL; range, 0.16-21.9 ng/mL; vs preterm labor and delivery without microbial invasion of the amniotic cavity: median, 1.7 ng/mL; range, 0.45-21.6 ng/mL; vs preterm labor with term delivery: median, 1.2 ng/mL; range, 0.17-42. 1 ng/mL; P <.01 for each comparison; and preterm premature rupture of membranes without microbial invasion of the amniotic cavity: median, 1.7 ng/mL; range, 0.29-13.9 ng/mL; vs preterm premature rupture of membranes with microbial invasion of the amniotic cavity: median, 3.6 ng/mL; range, 0.59-20.3 ng/mL; P <.01). CONCLUSION: Matrilysin is a physiologic constituent of amniotic fluid, and its concentration increases with advancing gestational age. Microbial invasion of the amniotic cavity in preterm gestations was associated with a significant increase in amniotic fluid concentration of matrilysin. Matrilysin therefore may play a role in the host defense mechanism.

A study of the relationship between placenta growth factor and gestational age, parturition, rupture of membranes, and intrauterine infection.

OBJECTIVE: Placenta growth factor is a potent angiogenic factor produced by the human placenta that has been implicated in the pathogenesis of preeclampsia and intrauterine growth restriction. Placenta growth factor belongs to the vascular endothelial growth factor family and is capable of inducing proliferation, migration, and activation of endothelial cells. The objective of this study was to determine the relationship between amniotic fluid concentration of placenta growth factor and gestational age, parturition (term and preterm), spontaneous rupture of the membranes, and intra-amniotic infection. STUDY DESIGN: Amniotic fluid samples obtained from 273 pregnant patients were assayed in the following clinical groups: midtrimester pregnancy, preterm labor who delivered at term, preterm labor without microbial invasion of the amniotic cavity who delivered preterm, preterm labor with microbial invasion of the amniotic cavity, term not in labor, term in labor, term with microbial invasion of the amniotic cavity, preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, and term with premature rupture of membranes without microbial invasion of the amniotic cavity. The placenta growth factor concentrations were determined by an immunoassay that is both sensitive and specific. RESULTS: Placenta growth factor was detectable in 96.3% (263/273) of samples. Amniotic fluid placenta growth factor concentration decreased with advancing gestational age (r = -0.42; P <.001). Amniotic fluid placenta growth factor concentrations were significantly higher in women in midtrimester pregnancy than in those at term not in labor (midtrimester pregnancy: median, 43.1 pg/mL; range, 22.9-69.8 pg/mL; vs term not in labor: median, 28.7 pg/mL; range, 16.1-82.7 pg/mL; P <.01). Neither term nor preterm parturition was associated with a change in amniotic fluid placenta growth factor concentrations. Term premature rupture of membranes was associated with a significant decrease in amniotic fluid placenta growth factor concentration (term premature rupture of membranes: median, 16.5 pg/mL; range <5.2-195.1 pg/mL; vs term intact membranes: median, 28.7 pg/mL; range, 16.1-822.7 pg/mL; P <.005). Preterm premature rupture of membranes was not associated with changes in amniotic fluid placenta growth factor concentrations. Intra-amniotic infection in preterm labor, term labor with intact membranes, and preterm premature rupture of membranes were not associated with changes in amniotic fluid placenta growth factor concentrations. CONCLUSION: Placenta growth factor is a physiologic constituent of amniotic fluid. Amniotic fluid concentrations of placenta growth factor decrease with advancing gestational age. Neither parturition nor infection affects amniotic fluid placenta growth factor concentrations.