Background
Preterm prelabor rupture of the membranes (PPROM) is frequently complicated by intraamniotic inflammatory processes such as intraamniotic infection and sterile intraamniotic inflammation. Antibiotic therapy is recommended to patients with PPROM to prolong the interval between this complication and delivery (latency period), reduce the risk of clinical chorioamnionitis, and improve neonatal outcome. However, there is a lack of information regarding whether the administration of antibiotics can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with PPROM.
Objective
The first aim of the study was to determine whether antimicrobial agents can reduce the magnitude of the intraamniotic inflammatory response in patients with PPROM by assessing the concentrations of interleukin-6 in amniotic fluid before and after antibiotic treatment. The second aim was to determine whether treatment with intravenous clarithromycin changes the microbial load of Ureaplasma spp DNA in amniotic fluid.
Study Design
A retrospective cohort study included patients who had (1) a singleton gestation, (2) PPROM between 24+0 and 33+6 weeks, (3) a transabdominal amniocentesis at the time of admission, and (4) intravenous antibiotic treatment (clarithromycin for patients with intraamniotic inflammation and benzylpenicillin/clindamycin in the cases of allergy in patients without intraamniotic inflammation) for 7 days. Follow-up amniocenteses (7 th day after admission) were performed in the subset of patients with a latency period lasting longer than 7 days. Concentrations of interleukin-6 were measured in the samples of amniotic fluid with a bedside test, and the presence of microbial invasion of the amniotic cavity was assessed with culture and molecular microbiological methods. Intraamniotic inflammation was defined as a bedside interleukin-6 concentration ≥745 pg/mL in the samples of amniotic fluid. Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity.
Results
A total of 270 patients with PPROM were included in this study: 207 patients delivered within 7 days and 63 patients delivered after 7 days of admission. Of the 63 patients who delivered after 7 days following the initial amniocentesis, 40 underwent a follow-up amniocentesis. Patients with intraamniotic infection (n = 7) and sterile intraamniotic inflammation (n = 7) were treated with intravenous clarithromycin. Patients without either microbial invasion of the amniotic cavity or intraamniotic inflammation (n = 26) were treated with benzylpenicillin or clindamycin. Treatment with clarithromycin decreased the interleukin-6 concentration in amniotic fluid at the follow-up amniocentesis compared to the initial amniocentesis in patients with intraamniotic infection (follow-up: median, 295 pg/mL, interquartile range [IQR], 72–673 vs initial: median, 2973 pg/mL, IQR, 1750–6296; P = .02) and in those with sterile intraamniotic inflammation (follow-up: median, 221 pg/mL, IQR 118–366 pg/mL vs initial: median, 1446 pg/mL, IQR, 1300–2941; P = .02). Samples of amniotic fluid with Ureaplasma spp DNA had a lower microbial load at the time of follow-up amniocentesis compared to the initial amniocentesis (follow-up: median, 1.8 × 10 4 copies DNA/mL, 2.9 × 10 4 to 6.7 × 10 8 vs initial: median, 4.7 × 10 7 copies DNA/mL, interquartile range, 2.9 × 10 3 to 3.6 × 10 7 ; P = .03).
Conclusion
Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation. Moreover, treatment with clarithromycin was related to a reduction in the load of Ureaplasma spp DNA in the amniotic fluid of patients with PPROM <34 weeks of gestation.
Preterm prelabor rupture of the membranes (PPROM) is characterized by the rupture of fetal membranes and leakage of amniotic fluid before the onset of regular uterine activity <37 weeks of gestation. PPROM complicates approximately 3–4% of all deliveries and is responsible for one third of all deliveries <37 weeks. PPROM is one of the great obstetrical syndromes because of its multiple etiologies, a long preclinical phase, fetal involvement, and a complex interaction between the maternal and fetal genome and the environment. ,
Why was the study performed?
To determine the effect of intravenous clarithromycin therapy on the intensity of the intraamniotic inflammatory response in a subset of pregnancies with preterm prelabor rupture of the membranes (PPROM) <34 weeks complicated by intraamniotic infection and sterile intraamniotic inflammation by assessing the concentrations of interelukin-6 in amniotic fluid before and after antibiotic treatment and to evaluate the effect of intravenous clarithromycin therapy on the microbial load of Ureaplasma spp DNA in amniotic fluid.
Key findings
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Treatment with clarithromycin was associated with the attenuation of the intensity of the intraamniotic inflammatory response in patients with intraamniotic infection who underwent a follow-up amniocentesis.
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Treatment with clarithromycin led to the reduction in the microbial load of Ureaplasma spp DNA in amniotic fluid, measured by the gene copy numbers in amniotic fluid.
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Treatment with clarithromycin was associated with the attenuation of the intensity of the intraamniotic inflammatory response in patients with sterile intraamniotic inflammation who underwent a follow-up amniocentesis.
What does this add to what is known?
This study provides objective evidence that treatment with clarithromycin can down-regulate the intraamniotic inflammatory response, as well as the presence of microorganisms, in a subset of patients with PPROM.
PPROM is often complicated by the presence of microorganisms in the amniotic fluid (ie, microbial invasion of the amniotic cavity [MIAC] ), with Ureaplasma spp being the most frequent microorganisms, , , and intraamniotic inflammation. , , , , ,
The combination of these 2 conditions creates the following clinical subtypes of PPROM: (1) intraamniotic infection (defined by the presence of both MIAC and intraamniotic inflammation); (2) sterile intraamniotic inflammation; (3) MIAC without intraamniotic inflammation; or (4) without either MIAC or intraamniotic inflammation. , There is evidence that the earlier the gestational age at PPROM, the higher the rates of MIAC, , intraamniotic infection, , and sterile intraamniotic inflammation.
The current standard management of patients with PPROM <34 weeks of gestation consists of an expectant approach, including the administration of corticosteroids and antibiotics. Antibiotics are recommended for all patients with PPROM to prolong the latency period (interval between membrane rupture and delivery) and to reduce the rate of clinical chorioamnionitis, , early-onset neonatal sepsis, and the need for surfactant therapy replacement and oxygen therapy. Antibiotics are thought to treat or prevent subclinical intraamniotic infection from the ascension of bacteria from the vagina or cervix.
Recently, antibiotic therapy has been shown to reduce the intensity of the intraamniotic inflammatory response in a subset of patients with spontaneous preterm delivery with intact membranes as well as in patients with cervical insufficiency. However, the knowledge about the effect of antibiotics in the treatment of intraamniotic inflammatory complications in PPROM is less clear. ,
In 2006, Gomez et al reported that the antibiotic treatment of ceftriaxone, clindamycin, and erythromycin can rarely eradicate intraamniotic infection. Ten years later, Lee et al showed that an intensive antibiotic treatment of ceftriaxone, clarithromycin, and metronidazole reduced intraamniotic infection by about 33%. These authors used clarithromycin, a semisynthetic macrolide, instead of erythromycin. The rationale for this choice was that Ureaplasma spp are resistant to erythromycin in up to 80% of cases. ,
Clarithromycin, aside from its effective antibacterial activity against Ureaplasma spp, shows optimal placental passage. , In addition, this antibiotic is capable of inhibiting the production of proinflammatory cytokines. Thus, clarithromycin might be effective not only in the treatment of intraamniotic infection caused by Ureaplasma spp but also in the treatment of sterile intraamniotic inflammation in patients with PPROM. This antimicrobial agent also has antiinflammatory properties through its actions in inhibiting the transcription factors of nuclear factor (NF) kappa B and activator protein (AP)-1, , which are major regulators in proinflammatory response.
This study had 3 objectives: (1) to determine the effect of intravenous clarithromycin therapy on the intensity of the intraamniotic inflammatory response, by assessing the concentrations of interleukin (IL)-6 in amniotic fluid, in a subset of pregnancies with PPROM <34 weeks complicated by intraamniotic infection and sterile intraamniotic inflammation before and after antibiotic treatment; (2) to evaluate the effect of intravenous clarithromycin therapy on the microbial load of Ureaplasma spp DNA in amniotic fluid; and (3) to assess the effect of intravenous therapy with nonmacrolide antibiotics (benzylpenicillin/clindamycin) on the amniotic fluid IL-6 concentrations of patients without either MIAC or intraamniotic inflammation.
Materials and Methods
A retrospective cohort study was conducted in pregnant patients who were admitted to the Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Czech Republic, between January 2014 and May 2019. Eligible patients who met the following criteria were selected for participation in this study: (1) age ≥18 years; (2) singleton pregnancy; (3) PPROM between gestational ages 24+0 and 33+6 weeks; and (4) written informed consent obtained for transabdominal amniocentesis at the time of admission.
Patients were excluded if: (1) the planned amniocentesis was not performed; (2) they had pregestational or gestational diabetes mellitus and/or chronic hypertension or gestational hypertension or preeclampsia; (3) the fetus had signs of fetal growth restriction, a congenital structural abnormality, or a chromosomal abnormality; or (4) active vaginal bleeding was present.
Gestational age was established by first-trimester fetal biometry. PPROM was diagnosed by examination with a sterile speculum to verify the pooling of amniotic fluid in the vagina. If uncertainty remained, leakage of amniotic fluid was confirmed by the presence of insulin-like growth factor binding proteins in the vaginal fluid (ACTIM PROM test; MedixBiochemica, Kauniainen, Finland). This test has been previously documented to be valuable for the diagnosis of PPROM, and patients with a positive test and intact membranes are at risk for impending term or preterm delivery. The performance of transabdominal amniocentesis to assess the intraamniotic environment (bedside IL-6 test and MIAC) was offered to each patient admitted with a singleton pregnancy complicated by PPROM as a part of the clinical management of singleton pregnancies with PPROM.
Ultrasound-guided transabdominal amniocentesis was performed at the time of admission before administration of corticosteroids and antibiotics, and approximately 3 mL of amniotic fluid was aspirated. A total of 100 μL of noncentrifuged amniotic fluid was used for the bedside assessment of IL-6 concentrations. The remaining amniotic fluid was immediately dispensed into 3 polypropylene tubes.
The first and second tubes, containing uncentrifuged samples of amniotic fluid, were immediately transported to the molecular biology and microbiology laboratories for polymerase chain reaction (PCR) testing for Ureaplasma spp, Mycoplasma hominis , and Chlamydia trachomatis to evaluate 16S ribosomal RNA (rRNA) and for cultivation of amniotic fluid, respectively. The last tube was centrifuged for 15 minutes at 2000 g to remove cells and debris, divided into aliquots, and stored at −70°C.
Initial antibiotic treatment began once the results of amniotic fluid IL-6 were available. Patients with intraamniotic inflammation (a concentration of bedside IL-6 ≥745 pg/mL) received clarithromycin intravenously, 500 mg every 12 hours, for 7 days, unless delivery occurred. Patients without intraamniotic inflammation (a concentration of bedside IL-6 <745 pg/mL , ) were treated with benzylpenicillin, initially, 5.0 million IU intravenously and, further, 2.5 million IU every 6 hours intravenously for 7 days, unless delivery occurred.
In case of a penicillin allergy, patients were treated with clindamycin, 900 mg intravenously every 8 hours for 7 days, unless delivery occurred. Once the final results from cultivation or PCR were known, the attending clinician made individualized treatment to determine the optimal antibiotic therapy.
Patients received a course of corticosteroid treatment: betamethasone 14 mg intramuscularly, 24 hours apart. Tocolytic therapy was not routinely used at admission; however, if steroids were administered to induce fetal lung maturity, tocolysis with nifedipine or atosiban was administered to patients without intraamniotic inflammation if they experienced regular increased uterine contractility. The decision was based on the discretion of the attending clinician.
Patients with intraamniotic infection (proven MIAC and intraamniotic inflammation) >28+0 weeks of gestation were managed actively: labor was induced or an elective caesarean delivery was performed after completing corticosteroid treatment but no later than 72 hours after the rupture of the membranes. Other patients were managed expectantly.
A follow-up amniocentesis was offered to patients with PPROM when antibiotic treatment ended.
The collection of amniotic fluid samples for research purposes was approved by the Institutional Review Board of University Hospital Hradec Kralove (March 19, 2008: number 200804 SO1P; renewed in July 2014: number 201407 S14P), and written informed consent was received from all participants prior to sampling. The use of amniocentesis for the management of PPROM in our department has been the subject of several reports. , This also applies to the use of initial and follow-up amniocenteses to assess the response to antimicrobial therapy. , ,
Bedside testing for the concentration of interleukin-6 in amniotic fluid
The IL-6 concentration in fresh uncentrifuged amniotic fluid was assessed with a Milenia QuickLine IL-6 lateral flow immunoassay (Milenia POCScan Reader; Milenia Biotec, GmbH, Giessen, Germany). The measurement range was 50–10,000 pg/mL. The intra- and interassay coefficients of variation were 12.1% and 15.5%, respectively. This point-of-care test is available for patient care in Europe and has been approved by regulatory agencies.
Detection of Ureaplasma spp, Mycoplasma hominis , and Chlamydia trachomatis
DNA was isolated from the amniotic fluid with a QIAamp DNA minikit (QIAGEN, Hilden, Germany), according to the manufacturer’s instructions (using the protocol for the isolation of bacterial DNA from biological fluids). Real-time PCR was performed on a Rotor-Gene 6000 instrument (QIAGEN) with the commercial kit AmpliSens C trachomatis / Ureaplasma / M hominis -FRT (Federal State Institution of Science, Central Research Institute of Epidemiology, Moscow, Russia) to detect the DNA from Ureaplasma spp, M hominis , and C trachomatis in a common PCR tube.
As a control, a PCR run for beta-actin, a housekeeping gene, was included to assess the presence of inhibitors of the polymerase chain reaction. The amount of Ureaplasma spp DNA in copies per milliliter was determined by absolute quantification using an external calibration curve. Plasmid DNA (pCR4; Invitrogen, Waltham, MA) was used for the preparation of the calibration curve. The concentration of Ureaplasma spp DNA in copies per microliter was converted into copies per milliliter using the following formula: concentration of Ureaplasma spp DNA (copies/µL) x elution volume (µL)/input volume (mL).
Detection of other bacteria in amniotic fluid
Bacterial DNA was identified by PCR targeting the 16S rRNA gene with the following primers: 5ꞌ-CCAGACTCCTACGGGAGGCAG-3ꞌ (V3 region) and 5ꞌ-ACATTTCACAACACGAGCTGACGA-3ꞌ (V6 region). , Each individual reaction contained 3 μL of target DNA, 500 nM of forward and reverse primers, and Q5 high-fidelity DNA polymerase (New England Biolabs Inc, Ipswich, MA) in a total volume of 25 μL. The amplification was performed in a 2720 Thermal Cycler (Applied Biosystems, Foster City, CA).
The products were visualized on an agarose gel. Positive reactions yielded products of 950 bp, which were subsequently analyzed by sequencing. The 16S PCR products were cleaned and used in sequencing PCR reactions, utilizing the previously named primers and the BigDye terminator cycle sequencing kit, version 3.1 (ThermoFisher Scientific, Waltham, MA). Bacteria were then typed using the sequences obtained in BLAST and SepsiTest M BLAST. These tests are routinely offered clinically in our medical center and do not represent research tests. ,
Aerobic and anaerobic cultures of amniotic fluid
The amniotic fluid samples were cultured on Columbia agar with sheep’s blood, a Gardnerella vaginalis selective medium, MacConkey agar, a Neisseria -selective medium (modified Thayer-Martin medium), Sabouraud agar, or Schaedler anaerobe agar. The plates were cultured for 6 days and checked daily. The species were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with the MALDI Biotyper software (Bruker Daltonics, Bremen, Germany).
Diagnosis of microbial invasion of the amniotic cavity
MIAC was defined as the presence of microorganisms detected by culture and/or the detection of microbial nucleic acids in amniotic fluid.
Definitions of intraamniotic inflammation, intraamniotic infection, and sterile intraamniotic inflammation
The diagnosis of intraamniotic inflammation in pregnancies with PPROM was defined as a concentration of bedside IL-6 in amniotic fluid ≥745 pg/mL. , We are aware of other studies in which a cutoff concentration of IL-6 of 2.6 ng/mL was used to define intraamniotic inflammation ; however, our study used a point-of-care immunoassay in which the cutoff for the detection of intraamniotic inflammation was ≥745 pg/mL.
Intraamniotic infection was defined as the presence of MIAC with intraamniotic inflammation. Sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without MIAC.
Diagnosis of histologic chorioamnionitis and funisitis
The degree of polymorphonuclear leukocyte infiltration was assessed separately in the free membranes (amnion and choriodecidua), chorionic plate, and umbilical cord according to the criteria provided by Kim and colleagues. The diagnosis of histologic chorioamnionitis was based on the presence of inflammatory changes in the choriodecidua (grades 3–4), chorionic plate (grades 3–4), umbilical cord (grades 1–4), and/or amnion (grades 1–4). The diagnosis of funisitis was based on the presence of inflammatory changes in the umbilical cord (grades 1–4).
Diagnosis of short-term neonatal morbidity
Maternal and perinatal medical records were reviewed by 5 investigators (M.K., M.S., J.S., J.M., and I.M.). Composite neonatal morbidity was defined in this study as the need for intubation during hospitalization and/or respiratory distress syndrome (defined by the presence of 2 or more of the following criteria: evidence of respiratory compromise, persistent oxygen requirement for more than 24 hours, administration of exogenous surfactant, and radiographic evidence of hyaline membrane disease) and/or bronchopulmonary dysplasia (defined as oxygen requirement at 28 days of age) and/or pneumonia (diagnosed by abnormal findings on chest X-rays) and/or retinopathy of prematurity (identified using retinoscopy) and/or intraventricular hemorrhage (diagnosis made using cranial ultrasound examinations according to the procedure of Papile et al ) and/or necrotizing enterocolitis (defined as radiological findings of either intramural gas or portal venous gas with or without free intraabdominal gas) and/or early- (during the first 72 hours of life) or late-onset (between the ages of 4 and 120 days) sepsis (either proven by bacterial culture or strong clinical suspicion of sepsis) and/or neonatal death before hospital discharge.
Statistical analysis
Demographic characteristics were compared by the nonparametric Kruskal-Wallis and Mann-Whitney U tests for continuous variables and presented as the median (interquartile range [IQR]). Categorical variables were compared with the χ 2 or Fisher exact test and presented as numbers (percentages). Normality of the data was tested using the Anderson-Darling and D’Agostino-Pearson omnibus normality tests. Concentrations of IL-6 and microbial loads of Ureaplasma spp DNA in amniotic fluid between the initial and follow-up amniocenteses were compared with the Wilcoxon matched-pairs signed rank test.
Differences were considered statistically significant at P < .05. All P values were obtained from 2-sided tests, and all statistical analyses were performed using GraphPad Prism 8.1.2 for Mac OS X (GraphPad Software, San Diego, CA) or the SPSS 19.0 statistical package for Mac OS X (SPSS Inc, Chicago, IL).
Results
Three hundred seventeen patients with PPROM met the entry criteria. An initial amniocentesis was performed in 98% of patients (312 of 317) (amniocentesis could not be performed because of anhydramnios and delivery occurred before the procedure in 3 and 2 patients, respectively). Subsequently, 42 patients were excluded from the study because of fetal growth restriction (n = 18), gestational diabetes mellitus (n = 9), chronic hypertension (n = 7), pregestational diabetes mellitus (n = 5), preeclampsia (n = 1), gestational hypertension (n = 1), and active severe vaginal bleeding (n = 1). Therefore, the remaining 270 patients are included in this report.
The overall rate of MIAC and intraamniotic inflammation was 29% (79 of 270) and 28% (75 of 270), respectively. The presence of intraamniotic infection was diagnosed in 20% (55 of 270), sterile intraamniotic inflammation in 7% (20 of 270), and MIAC without intraamniotic inflammation in 9% (24 of 270) of patients.
Twenty-three percent of patients (63 of 270) delivered >7 days after admission, and 37% (23 of 63) of them did not have a follow-up amniocentesis for the following reasons: (1) the follow-up amniocentesis was declined by the patient (n = 12); (2) the managing clinicians decided not to perform a follow-up amniocentesis (n = 4); (3) labor began on the day of the follow-up amniocentesis (n = 4); or (4) the follow-up amniocentesis could not be performed because of anhydramnios (n = 3). The remaining 63% of patients (40 of 63) underwent a follow-up amniocentesis ( Figure 1 ). The flow and antibiotic management of the patients who underwent a follow-up amniocentesis are shown in Figure 2 .
The demographical and clinical data of patients who delivered ≤7 days and >7 days after admission without or with follow-up amniocentesis are shown in Table 1 . Bacterial species identified in amniotic fluid from the initial amniocentesis are listed in Table 2 . Short-term outcomes of the newborns from PPROM pregnancies are listed in Table 3 .
| Characteristic | Delivery ≤ 7 days after admission (n = 207) | Delivery >7 days after admission without a follow-up amniocentesis (n = 23) | Delivery >7 days after admission with a follow-up amniocentesis (n = 40) | P value |
|---|---|---|---|---|
| Maternal age, y, median (IQR) | 31 (27–36) | 33 (29–37) | 31 (29–34) | .47 |
| Primiparous, n (%) | 98 (47%) | 10 (44%) | 12 (30%) | .13 |
| Prepregnancy body mass index, kg/m 2 , median (IQR) | 23.6 (21.1–26.7) | 24.1 (21.6–28.3) | 23.4 (20.4–25.9) | .52 |
| Smoking, n (%) | 36 (17%) | 3 (13%) | 5 (13%) | .67 |
| History of preterm prelabor rupture of the membranes, n (%) | 13 (6%) | 2 (9%) | 2 (5%) | .84 |
| Time interval between rupture of the membranes and amniocentesis, h, median (IQR) | 5 (3–10) | 5 (2–10) | 7 (3–14) | .25 |
| Gestational age at admission, wks, median (IQR) | 32+1 (30+5 to 33+2) | 30+0 (27+5 to 31+2) | 28+0 (25+3 to 31+1) | < .0001 |
| Gestational age at delivery, wks, median (IQR) | 32+4 (30+6 to 33+4) | 31+4 (29+2 to 33+1) | 32+0 (29+4 to 33+2) | .12 |
| Latency period, d, median (IQR) | 2 (1–3) | 12 (9–14) | 17 (12–28) | < .0001 |
| Amniotic fluid interleukin-6 concentrations at admission, pg/mL, median (IQR) | 250 (134–887) | 188 (50–327) | 383 (158–1424) | .12 |
| Maternal serum C-reactive protein concentrations at admission, mg/L, median (IQR) | 6.1 (2.7–11.3) | 5.8 (3.1–8.6) | 4.1 (1.6–8.1) | .07 |
| Maternal white blood cells count at admission, × 10 9 L, median (IQR) | 13.0 (10.5–16.0) | 12.2 (9.1–14.5) | 12.1 (10.2–14.2) | .05 |
| Vaginal-rectal presence of Streptococcus agalactiae | 25 (12%) | 3 (13%) | 3 (8%) | .69 |
| Microbial invasion of the amniotic cavity, n (%) | 67 (32%) | 5 (22%) | 7 (18%) | .06 |
| Intraamniotic inflammation, n (%) | 58 (28%) | 3 (13%) | 14 (35%) | .17 |
| Intraamniotic infection, n (%) | 46 (22%) | 2 (9%) | 7 (18%) | .28 |
| Sterile intraamniotic inflammation, n (%) | 12 (6%) | 1 (4%) | 7 (18%) | .03 |
| Microbial invasion of the amniotic cavity without intraamniotic inflammation, n (%) | 23 (11%) | 3 (13%) | 0 (0%) | .08 |
| Administration of antibiotics, n (%) | 207 (100%) | 23 (100%) | 40 (100%) | — |
| Administration of corticosteroids, n (%) | 201 (97%) | 22 (96%) | 40 (100%) | .49 |
| Spontaneous vaginal delivery, n (%) | 138 (67%) | 7 (30%) | 21 (53%) | .001 |
| Cesarean delivery, n (%) | 68 (33%) | 16 (70%) | 19 (47%) | .02 |
| Forceps delivery, n (%) | 1 (1%) | 0 (0%) | 0 (0%) | .86 |
| Birthweight, g, median (IQR) | 1880 (1550–2130) | 1700 (1190–1960) | 1630 (1310–2060) | .03 |
| Apgar score <7, 5 min, n (%) | 6 (3%) | 2 (9%) | 2 (5%) | .34 |
| Apgar score <7, 10 min, n (%) | 5 (2%) | 0 (0%) | 0 (0%) | .46 |
| Intraamniotic infection (n = 55) | Microbial invasion of the amniotic cavity without intra-amniotic inflammation (n = 24) | ||||
|---|---|---|---|---|---|
| Delivery ≤7 days after admission (n = 46) | Delivery >7 days after admission without a follow-up amniocentesis (n = 2) | Delivery >7 days after admission with a follow-up amniocentesis (n = 7) | Delivery ≤7 days after admission (n = 21) | Delivery >7 days after admission without a follow-up amniocentesis (n = 3) | Delivery >7 days after admission with a follow-up amniocentesis (n = 0) |
| Ureaplasma species (n = 21) | Ureaplasma species (n = 1) | Ureaplasma species (n = 6) | Ureaplasma species (n = 14) | Ureaplasma species (n = 2) | |
| Ureaplasma species plus Chlamydia trachomatis (n = 5) | Ureaplasma species plus Chlamydia trachomatis (n = 1) | Anaerococcus tetradius (n = 1) | Mycoplasma hominis (n = 2) | Lactobacillus iners (n = 1) | |
| Haemophilus influenzae (n = 4) | Chlamydia trachomatis (n = 1) | ||||
| Fusobacterium nucleatum (n = 2) | Haemophilus influenzae (n = 1) | ||||
| Streptococcus agalactiae (n = 2) | Gardnerella vaginalis (n = 1) | ||||
| Streptococcus anginosus (n = 2) | Ureaplasma species plus Chlamydia trachomatis (n = 1) | ||||
| Streptococcus pneumonia (n = 2) | Ureaplasma species plus Leptotrichia amnionii (n = 1) | ||||
| Chlamydia trachomatis (n = 1) | |||||
| Parvominas micra (n = 1) | |||||
| Peptoniphilus species (n = 1) | |||||
| Sneathia sanguinegens (n = 1) | |||||
| Streptococcus intermedius (n = 1) | |||||
| Leptotrichia amnionii plus Chlamydia trachomatis (n = 1) | |||||
| Ureaplasma species plus Sneathia sanguinegens (n = 1) | |||||
| Ureaplasma species + Veilonella species (n = 1) | |||||
| Variables | Delivery ≤ 7 days after admission (n = 207) | Delivery > 7 days after admission without a follow-up amniocentesis (n = 23) | Delivery > 7 days after admission with a follow-up amniocentesis (n = 40) | P value |
|---|---|---|---|---|
| Respiratory distress syndrome | 99 (48%) | 12 (52%) | 19 (48%) | .92 |
| Need for intubation | 13 (6%) | 1 (4%) | 6 (15%) | .13 |
| Intraventricular hemorrhage | 53 (26%) | 4 (17%) | 7 (18%) | .41 |
| Intraventricular hemorrhage (I–II) | 51 (25%) | 3 (13%) | 7 (18%) | .32 |
| Intraventricular hemorrhage (III–IV) | 2 (1%) | 1 (4%) | 0 (0%) | .26 |
| Necrotizing enterocolitis | 6 (3%) | 0 (0%) | 0 (0%) | .39 |
| Early-onset sepsis | 14 (7%) | 1 (4%) | 1 (3%) | .55 |
| Late-onset sepsis | 4 (2%) | 0 (0%) | 0 (0%) | .54 |
| Bronchopulmonary dysplasia | 15 (7%) | 3 (13%) | 5 (13%) | .40 |
| Retinopathy of prematurity | 3 (2%) | 0 (0%) | 1 (3%) | .73 |
| Pneumonia | 4 (2%) | 1 (4%) | 0 (0%) | .46 |
| Neonatal death | 4 (2%) | 1 (4%) | 0 (0%) | .46 |
| Composite neonatal morbidity | 126 (61%) | 15 (65%) | 24 (60%) | .91 |
The effect of clarithromycin therapy on intraamniotic inflammation in a subset of patients with intraamniotic infection
In the subset of patients with intraamniotic infection who had a follow-up amniocentesis and delivered >7 days after admission, the concentrations of IL-6 in amniotic fluid were lower in the samples from the follow-up amniocentesis than in the initial amniocentesis (follow-up: median, 295 pg/mL, IQR, 72-673 vs initial: median, 2973 pg/mL, IQR, 1750-6296; P = .02; Figure 3 A). Importantly, 86% of the patients (6 of 7) did not have intraamniotic inflammation at the time of the follow-up amniocentesis.
