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S N Caritis

Publications and source records attributed to S N Caritis.

At least 19 recordsLinked to original sources
PubMed2001

The Preterm Prediction Study: association between cervical interleukin 6 concentration and spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: The aim of this study was to determine the interrelationship between cervical concentration of interleukin 6 and detection of fetal fibronectin and other risk factors for spontaneous preterm birth. STUDY DESIGN: All patients with spontaneous preterm birth at <35 weeks' gestation (case patients; n = 125) and subjects matched for race, parity, and center delivered at > or = 37 weeks' gestation (n = 125; control subjects) were selected from women enrolled in the National Institute of Child Health and Human Development's Preterm Prediction Study. Interleukin 6 concentrations were determined by enzyme-linked immunosorbent assay in cervical swabs obtained at 22 weeks' to 24 weeks 6 days' gestation. Cutoffs to define an elevated interleukin 6 concentration included the 90th and 95th percentiles for control subjects (>305 and >538 pg/mL, respectively). RESULTS: The mean (+/-SD) interleukin 6 concentration was significantly higher in case patients than in control subjects (212 +/- 339 vs 111 +/- 186 pg/mL; P = .008). With either cutoff value elevated interleukin 6 concentration was significantly associated with spontaneous preterm birth (90th percentile, 20% vs 9.6%; P = .02; 95th percentile, 12% vs 4.8%; P = .04). Cervical interleukin 6 levels were highest within 4 weeks of delivery, and the trend continued until term. Elevated interleukin 6 concentration was not significantly associated with bacterial vaginosis, maternal body mass index <19.8 kg/m2, or a short cervix (< or = 25 mm), but it was significantly associated with a positive cervicovaginal fetal fibronectin test result (90th percentile, odds ratio, 5.5; 95% confidence interval, 2.6-11.9; 95th percentile, odds ratio, 5.3, 95% confidence interval, 2.1-12.9). The mean interleukin 6 concentration among women with a positive fibronectin test result was 373 +/- 406 pg/mL; that among women with a negative fetal fibronectin test result was 130 +/- 239 pg/mL (P = .001). In a regression analysis that adjusted for risk factors significantly associated with spontaneous preterm birth in this population (positive fetal fibronectin test result, body mass index <19.8 kg/m2, vaginal bleeding in the first or second trimester, previous spontaneous preterm birth, and short cervix) elevated cervical interleukin 6 concentration was not independently associated with spontaneous preterm birth (odds ratio, 1.8; 95% confidence interval, 0.8-4.3). CONCLUSIONS: At 24 weeks' gestation cervical interleukin 6 concentration in women who subsequently had a spontaneous preterm birth at <35 weeks' gestation was significantly elevated relative to those who were delivered at term. The association was particularly strong within 4 weeks of testing. A positive fetal fibronectin test result was strongly associated with elevated cervical interleukin 6 concentration, but bacterial vaginosis was not.

Case-Control Studies↗
PubMed2001

Occupational fatigue and preterm premature rupture of membranes. National Institute of Child Health and Human Development Maternal-Fetal Medicine, Units Network.

OBJECTIVE: The aim of this study was to prospectively determine the relationship between occupational fatigue and spontaneous preterm delivery segregated into the etiologically distinct categories of spontaneous preterm labor, preterm premature rupture of membranes, and indicated preterm delivery. STUDY DESIGN: A total of 2929 women with singleton pregnancies at 22 to 24 weeks' gestation were enrolled in a multicenter (10 sites) Preterm Prediction Study. Patients reported the number of hours worked per week and answered specific questions designed to determine the following 5 sources of occupational fatigue described by Mamelle et al: posture, work with industrial machines, physical exertion, mental stress, and environmental stress. Fatigue was quantified (0-5 index) according to the number of these sources positively reported. Simple and Mantel-Haenszel chi2 tests were used to test the univariate association and hypothesis of a linear trend between sources of occupational fatigue and spontaneous preterm delivery. Covariables were considered by multivariate logistic regression analysis. Women who did not work outside the home were considered separately from those who worked but did not report any sources of occupational fatigue. RESULTS: Each source of occupational fatigue was independently associated with a significantly increased risk of preterm premature rupture of membranes among nulliparous women but not among multiparous women. The risk of preterm premature rupture of membranes increased (P = .002) with an increasing number of sources of occupational fatigue-not working outside the home, 2.1%; working but not reporting fatigue, 3.7%; working with 1 source of fatigue, 3.2%; working with 2 sources of fatigue, 5.2%; working with 3 sources of fatigue, 5.1%; and working with 4 or 5 sources of fatigue, 7.4%. There was also a significant relationship (P = .01) between preterm premature rupture of membranes and an increasing number of hours worked per week among nulliparous women. Neither spontaneous preterm labor nor indicated preterm delivery was significantly associated with occupational fatigue among either nulliparous or multiparous women. CONCLUSION: The occupational fatigue index of Mamelle et al discriminated a group of nulliparous women at increased risk for preterm premature rupture of membranes. The relationship between preterm premature rupture of membranes and occupational fatigue or hours worked may provide guidelines according to which nulliparous women and their employers can be advised.

Adolescent↗
PubMed2001

The preterm prediction study: can low-risk women destined for spontaneous preterm birth be identified?

OBJECTIVE: Half of all preterm births occur in women without clinical risk factors. Our goal was to assess fetal fibronectin assay, Bishop score, and cervical ultrasonography as screening tests to predict which low-risk pregnancies will end in preterm birth. STUDY DESIGN: We performed a secondary analysis of data collected at 22 to 24 weeks' gestation from low-risk subjects enrolled in the Preterm Prediction Study, an observational study of risk factors for preterm birth conducted by the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Analysis was limited to primigravid women and to women who did not have a history of preterm birth or spontaneous pregnancy loss at <20 weeks' gestation. Bishop score (> or =4), fetal fibronectin level (> or =50 ng/mL), and cervical length (< or =25 mm) at 24 weeks' gestation were evaluated alone and in sequence as tests to predict spontaneous delivery before 35 weeks' gestation. RESULTS: Of the 2929 subjects enrolled in the original study, 2197 (1207 primigravid women and 900 low-risk multiparous women) met criteria for this analysis. There were 64 spontaneous births before 35 weeks' gestation (3.04%). All three tests were significantly related to birth before 35 weeks' gestation (high Bishop score: relative risk, 3.6; 95% confidence interval, 2.1-6.3; fetal fibronectin detection: relative risk, 8.2; 95% confidence interval, 4.8-13.9; short cervical length: relative risk, 6.9; 95% confidence interval, 4.3-11.1). However, the sensitivities of the tests alone were low (23.4% for high Bishop score, 23.4% for fetal fibronectin detection, and 39.1% for short cervix), as were the sensitivities for Bishop score followed by cervical ultrasonography (14.1%) and fetal fibronectin assay followed by cervical scan (15.6%). CONCLUSION: In the setting of low-risk pregnancy, fetal fibronectin assay and cervical ultrasonography have low sensitivity for preterm birth before 35 weeks' gestation. Sequential screening with Bishop score or fetal fibronectin assay followed by cervical ultrasonography further decreased sensitivity to only 15% among low-risk women.

Cervix Uteri↗
PubMed2001

The Preterm Prediction Study: toward a multiple-marker test for spontaneous preterm birth.

OBJECTIVE: The Preterm Prediction Study evaluated 28 potential biologic markers for spontaneous preterm birth in asymptomatic women at 23 to 24 weeks gestational age. This analysis compares those markers individually and in combination for an association with spontaneous preterm birth at <32 and <35 weeks gestational age. STUDY DESIGN: With the use of a nested case-control design from an original cohort study of 2929 women, results of tests from 50 women with a spontaneous preterm birth at <32 weeks and 127 women with a spontaneous preterm birth at <35 weeks were compared with results from matched-term control subjects. RESULTS: In the univariate analysis, the most potent markers that are associated with spontaneous preterm birth at <32 weeks by odds ratio were a positive cervical-vaginal fetal fibronectin test (odds ratio, 32.7) and <10th percentile cervical length (odds ratio, 5.8), and in serum, >90th percentiles of alpha-fetoprotein (odds ratio, 8.3) and alkaline phosphatase (odds ratio, 6.8), and >75th percentile of granulocyte colony-stimulating factor (odds ratio, 5.5). Results for spontaneous preterm birth at <35 weeks were generally similar but not as strong. Univariate and multivariate logistic regression analyses demonstrated little interaction among the tests in their association with spontaneous preterm birth. Combinations of the 5 markers were evaluated for their association with <32 weeks spontaneous preterm birth. Ninety-three percent of case patients had at least 1 positive test result versus 34% of control subjects (odds ratio, 24.0; 95% CI, 6.4-93.4). Among the case patients, 59% had >or=2 positive test results versus 2.4% of control subjects (odds ratio, 56.5; 95% CI, 7.1-451.7). If a cutoff of 3 positive test results was used, 20% of case patients and none of the control subjects had positive test results (P < .002). With the use of only the 3 serum tests (alkaline phosphatase, alpha-fetoprotein, and granulocyte colony-stimulating factor), any positive test identified 81% of cases versus 22% of control subjects (odds ratio, 14.7; 95% CI, 5.0-42.7). For spontaneous preterm birth at <35 weeks gestation, any 2 positive tests identified 43% of cases and 6% of control subjects (odds ratio, 11.2; 95% CI, 4.8-26.2). CONCLUSION: Overlap among the strongest biologic markers for spontaneous preterm birth is small. This suggests that the use of tests such as maternal serum alpha-fetoprotein, alkaline phosphatase, and granulocyte colony-stimulating factor as a group or adding their results to fetal fibronectin test and cervical length test results may enhance our ability to predict spontaneous preterm birth and that the development of a multiple-marker test for spontaneous preterm birth is feasible.

Alkaline Phosphatase↗
PubMed2000

Preterm prediction study: is socioeconomic status a risk factor for bacterial vaginosis in Black or in White women?

Bacterial vaginosis (BV), an important risk factor for preterm birth, is a more common infection in Black compared with White pregnant women. Because Black women in the United States are more likely to have lower measures of socioeconomic status (SES), this study examined the hypothesis that BV is associated with low SES. The project evaluated data from the Preterm Prediction Study of 2,929 women prospectively followed during their pregnancies. The women, who were screened for BV at 24 and 28 weeks of gestation, underwent a structured interview to evaluate demographic factors, SES, home and work environment, drug or alcohol use, and prior medical history. Black women in the study had many measures of lower SES compared with the White women, and reported less use of tobacco, alcohol and drugs. In neither the Black nor White women was an association found between BV and measures of SES (with the sole exception of "absence of a home telephone"). Most measures of SES do not explain the difference in rates of BV in Black and in White pregnant women.

Black or African American↗
PubMed2000

The preterm prediction study: granulocyte colony-stimulating factor and spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: Granulocyte colony-stimulating factor is elevated in the amniotic fluid and plasma of women with chorioamnionitis and active preterm labor. We investigated the relationship between plasma granulocyte colony-stimulating factor and subsequent spontaneous preterm birth in pregnant women without symptoms. STUDY DESIGN: We performed a nested case-control study involving 194 women who had a singleton spontaneous preterm birth and 194 matched term control subjects from the patient pool (n = 2929) enrolled in the Preterm Prediction Study. Plasma collected at 24 and 28 weeks' gestation was analyzed for granulocyte colony-stimulating factor, and the results were compared with subsequent spontaneous preterm birth. RESULTS: Compared with term control subjects, women who were delivered of their infants spontaneously at <28 weeks' gestation had increased mean granulocyte colony-stimulating factor values at 24 weeks' gestation (84.7 +/- 38.4 vs 67.7 +/- 28.6 pg/mL; P =.049), and women who were delivered of their infants at <32 weeks' gestation had increased mean plasma granulocyte colony-stimulating factor values at 28 weeks' gestation (80.4 +/- 24.1 vs 55.9 +/- 16.5 pg/mL; P =. 001). At 24 weeks' gestation a granulocyte colony-stimulating factor value >75th percentile in control subjects (approximately 80 pg/mL) was found in 48.9% (23/47) of all women delivered of their infants at <32 weeks' gestation versus 14.9% (7/47) of the term control subjects (adjusted odds ratio, 6.2; 95% confidence interval, 1.8-20. 8). At 28 weeks' gestation a granulocyte colony-stimulating factor value >75th percentile was found in 36.8% (7/19) of women delivered of their infants at <32 weeks' gestation versus 5.3% (1/19) of term control subjects (adjusted odds ratio, 25.7; 95% confidence interval, 1.5-470.4). When measured at 24 or 28 weeks' gestation, granulocyte colony-stimulating factor did not predict spontaneous preterm birth at 32 to 34 weeks' gestation or at 35 to 36 weeks' gestation. CONCLUSION: In pregnant women without symptoms at 24 and 28 weeks' gestation, elevated plasma granulocyte colony-stimulating factor levels are associated with subsequent early (<32 weeks' gestation) spontaneous preterm birth, especially within the next 4 weeks, but not with late spontaneous preterm birth. These data provide further evidence that early spontaneous preterm birth is associated with an inflammatory process that is identifiable by the presence of a cytokine in maternal plasma several weeks before the early spontaneous preterm birth; however, later spontaneous preterm birth is not associated with this process.

Adolescent↗
PubMed2000

The preterm prediction study: cervical lactoferrin concentration, other markers of lower genital tract infection, and preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: This study was undertaken to determine the relationship among cervical lactoferrin concentration, other cervical markers potentially related to infection, and spontaneous preterm birth. STUDY DESIGN: Cervical lactoferrin concentrations obtained at 22 to 24 weeks' gestation among 121 women who had a spontaneous preterm birth <35 weeks' gestation were compared with cervical lactoferrin concentrations among 121 women matched for race, parity, and center who were delivered at >/=37 weeks' gestation. Results were compared against levels of cervical interleukin 6, fetal fibronectin, and sialidase, against cervical length according to ultrasonography, and according to the bacterial vaginosis Gram stain score. RESULTS: Cervical lactoferrin concentrations ranged from not measurable (19% of the concentrations were below the threshold for this assay) to a titer of >/=1:64. There was no significant difference in the overall distributions of lactoferrin concentrations between the case patients and control subjects (P =.18). Only when the highest titers of lactoferrin were considered were there more women in the spontaneous preterm birth group (6/121 vs 0/121; P =.03). According to Spearman correlation analyses the cervical lactoferrin concentrations were strongly related to interleukin 6 concentration (r =.51; P =.0001), sialidase activity (r =.38; P =.0001), and bacterial vaginosis (r =.38; P =.0001), were weakly related to fetal fibronectin (r =. 16; P =.01), and were not related to cervical length. With the 90th percentile (a dilution of 1:32) used as a cutoff to establish a dichotomous variable, lactoferrin concentration had the following odds ratios and 95% confidence intervals for associations with other potential markers of infection: bacterial vaginosis odds ratio, 4.8 (95% confidence interval, 2.2-10.3); interleukin 6 concentration odds ratio, 2.8 (95% confidence interval, 1.2-6.5); sialidase activity odds ratio, 5. 5 (95% confidence interval, 2.2-13.7); fetal fibronectin concentration odds ratio, 0.6 (95% confidence interval, 0.2-2.0); chlamydiosis odds ratio, 2.3 (95% confidence interval, 0.8-6.9); and short cervix odds ratio, 0.5 (95% confidence interval, 0.2-1.4). CONCLUSIONS: Lactoferrin found in the cervix correlated well with other markers of lower genital tract infection. High lactoferrin levels were associated with spontaneous preterm birth but had a very low predictive sensitivity.

Bacterial Infections↗
PubMed2000

The Preterm Prediction Study: sequential cervical length and fetal fibronectin testing for the prediction of spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVES: This study was undertaken to further elucidate the pathogenesis of preterm birth by means of traditional risk factors and new markers for preterm birth derived from the Preterm Prediction Study. STUDY DESIGN: A total of 3076 women (2929 with singleton gestations and 147 with twin pregnancies) were categorized according to the presence of risk factors including black race, low body mass index, the presence of bacterial vaginosis, and previous preterm birth. At 24 and 28 weeks' gestation cervical length was measured and categorized as short (</=25 mm) or normal (>25 mm). Vaginal and cervical fetal fibronectin concentrations were measured at 24, 26, 28, and 30 weeks' gestation and results were categorized as positive (>/=50 ng/mL) or negative (<50 ng/mL). RESULTS: At 24 to 26 weeks' gestation women with each of the risk factors were more likely to have positive fibronectin test results or to have a short cervix. Among women with negative fetal fibronectin results at 24 to 26 weeks' gestation those with a short cervix were more likely to have positive fetal fibronectin results at 28 to 30 weeks' gestation, and among those with normal cervical length those women who had positive fetal fibronectin results were more likely to have a short cervix at later evaluation. Most women who had positive fetal fibronectin results at 24 to 26 weeks' gestation had negative results at 28 to 30 weeks' gestation, whereas most but not all women who had a short cervix at 24 to 26 weeks' gestation still had a short cervix at 28 to 30 weeks' gestation. In each period women with both a positive fetal fibronectin result and a short cervix were at substantially increased risk of spontaneous preterm birth; women with either marker alone had intermediate and approximately equal risks of spontaneous preterm birth, and women without either marker had a low risk of spontaneous preterm birth. CONCLUSION: Regardless of other risk factors, a short cervix predicts a subsequent positive fetal fibronectin result, and a positive fetal fibronectin result predicts subsequent cervical shortening. These data do not support a single sequence of events leading to spontaneous preterm birth.

Biomarkers↗
PubMed2000

The Preterm Prediction Study: association of second-trimester genitourinary chlamydia infection with subsequent spontaneous preterm birth.

OBJECTIVE: This study was undertaken to determine the association between genitourinary tract infection with Chlamydia trachomatis and spontaneous preterm birth. STUDY DESIGN: Genitourinary tract infection with C trachomatis was determined with a ligase chain reaction assay of voided urine samples collected at 24 weeks' gestation (22 weeks' to 24 weeks 6 days' gestation) and 28 weeks' gestation (27 weeks' to 28 weeks 6 days' gestation). Case patients (spontaneous preterm birth at <37 weeks' gestation; n = 190) and control subjects (delivery at >/=37 weeks' gestation, matched for race, parity, and center; n = 190) were selected from 2929 women enrolled in the Preterm Prediction Study of the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. RESULTS: Genitourinary C trachomatis infection (11% overall) was significantly more common among the case patients than among the control subjects at 24 weeks' gestation (15.8% vs 6.3%; P =.003) but not at 28 weeks' gestation (12.6% vs 10.9%; P =.61). Women with chlamydia infection were more likely to have bacterial vaginosis (57.1% vs 32.9%; P =.002) and a short cervical length (</=25 mm; 33.0% vs 17.9%; P =.02) but not a body mass index <19.8 kg/m(2) (35.0% vs 23.9%; P =.17) or a positive fetal fibronectin test result (7.1% vs 9.5%; P =.62). After adjustment for risk factors for spontaneous preterm birth, women with C trachomatis infection at 24 weeks' gestation were 2 times as likely as uninfected women to have a spontaneous preterm birth at <37 weeks' gestation (odds ratio, 2.2; 95% confidence interval, 1.03-4.78) and 3 times as likely to have a spontaneous preterm birth at <35 weeks' gestation (odds ratio, 3.2; 95% confidence interval, 1.08-9.57). CONCLUSION: Genitourinary C trachomatis infection at 24 weeks' gestation was associated with a 2-fold to 3-fold increased risk of subsequent spontaneous preterm birth.

Adolescent↗
PubMed2000

The Preterm Prediction Study: prediction of preterm premature rupture of membranes through clinical findings and ancillary testing. The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: Our objective was to determine the relative importance of demographic characteristics, clinical risk factors, and ancillary screening tests in the prediction of preterm birth as a result of premature rupture of membranes. STUDY DESIGN: A total of 2929 women were evaluated in 10 centers at 23 to 24 weeks' gestation. Demographic and clinical characteristics were ascertained. Cervicovaginal fetal fibronectin and bacterial vaginosis were evaluated. Cervical length was measured by vaginal ultrasonography. Patients were evaluated for spontaneous preterm birth caused by preterm premature rupture of membranes at <37 and <35 weeks' gestation. Multivariate analyses were performed separately for nulliparous women and multiparous women. RESULTS: Premature rupture of membranes at <37 weeks' gestation complicated 4.5% of pregnancies, accounting for 32.6% of preterm births. Univariate analysis revealed low body mass index, pulmonary disease, contractions within 2 weeks, short cervix (</=25 mm), positive results of fetal fibronectin screening, bacterial vaginosis, and a previous preterm birth caused by premature rupture of membranes (in multiparous women) to be significantly associated with preterm birth caused by premature rupture of membranes in the current gestation. Short cervix, previous preterm birth caused by premature rupture of membranes in multiparous women, and presence of fetal fibronectin were the strongest predictors for both preterm birth caused by premature rupture of membranes at <37 and <35 weeks' gestation. Women with positive fetal fibronectin screening results and a short cervix had greater risks both of preterm birth caused by premature rupture of membranes at <37 weeks' gestation (relative risk, 4.9) and of preterm birth caused by premature rupture of membranes at <35 weeks' gestation (relative risk, 13.5) than did those without these risk factors. Multiparous women with all three risk factors had a 31. 3-fold increased risk of preterm birth caused by premature rupture of membranes at <35 weeks' gestation. CONCLUSION: The combination of short cervical length, previous preterm birth caused by preterm premature rupture of membranes, and positive fetal fibronectin screening results was highly associated with preterm delivery caused by preterm premature rupture of membranes in the current gestation.

Cervix Uteri↗
PubMed2000

The preterm prediction study: quantitative fetal fibronectin values and the prediction of spontaneous preterm birth. The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: A cervicovaginal fetal fibronectin value of >/=50 ng/mL has been used to define women at risk of having a preterm birth. We evaluated the relationship between quantitative fetal fibronectin values and spontaneous preterm birth. STUDY DESIGN: Cervical and vaginal specimens for fetal fibronectin were obtained at 24, 26, 28, and 30 weeks' gestation from 2926 women. Quantitative fetal fibronectin values were calculated by using absorbances determined by enzyme-linked immunosorbent assay. The highest fetal fibronectin value (cervical or vaginal) for each woman at each visit was evaluated in relation to spontaneous preterm birth at <35 weeks' gestation. Receiver operating characteristic curves were constructed to determine the optimal cutoff point for fetal fibronectin values to predict spontaneous preterm birth at <35 weeks' gestation and within 4 weeks of testing. RESULTS: The risk of spontaneous preterm birth increased as a function of increasing fetal fibronectin values from approximately 20 to 300 ng/mL. Fetal fibronectin values > or =300 ng/mL were not associated with a further increase in spontaneous preterm birth. Examination of the receiver operating characteristic curve indicates that the optimal cutoff point for a positive fetal fibronectin test result at 24 to 30 weeks' gestation to predict spontaneous preterm birth at <35 weeks is between 45 and 60 ng/mL. CONCLUSION: Increasing levels of cervicovaginal fetal fibronectin up to 300 ng/mL are associated with an increasing risk of spontaneous preterm birth. Nevertheless, at 24 to 30 weeks, the value currently used, 50 ng of fetal fibronectin per milliliter, appears to be a reasonable cutoff point for predicting spontaneous preterm birth at <35 weeks' gestation.

Cervix Uteri↗
PubMed2000

Preterm delivery in women with pregestational diabetes mellitus or chronic hypertension relative to women with uncomplicated pregnancies. The National institute of Child health and Human Development Maternal- Fetal Medicine Units Network.

OBJECTIVE: The purpose of this study was to compare the rates of indicated and spontaneous preterm delivery among women with chronic hypertension or pregestational diabetes mellitus with the rates among healthy women. STUDY DESIGN: This was a secondary analysis of data from healthy women with singleton gestations enrolled in a prospective observational study for prediction of preterm delivery (control group, n = 2738), women with pregestational diabetes mellitus requiring insulin therapy (n = 461), and women with chronic hypertension (n = 761). The two latter groups were enrolled in a randomized multicenter trial for prevention of preeclampsia. The main outcome measures were rates of preterm delivery, either spontaneous (preterm labor or rupture of membranes) or indicated (for maternal or fetal reasons), and neonatal outcomes. RESULTS: The overall rates of preterm delivery were significantly higher among women with diabetes mellitus (38%) and hypertension (33.1%) than among control women (13.9%). Rates were also significantly higher for delivery at <35 weeks' gestation. Women with diabetes mellitus had significantly higher rates of both indicated preterm delivery (21.9% vs 3.4%; odds ratio, 8.1; 95% confidence interval, 6.0-10.9) and spontaneous preterm delivery (16.1% vs 10.5%; odds ratio, 1.6; 95% confidence interval, 1.2-2.2) than did women in the control group. In addition, they had significantly higher rates of both indicated preterm delivery (odds ratio, 4.8; 95% confidence interval, 3.0-7.5) and spontaneous preterm delivery (odds ratio, 2.1; 95% confidence interval, 1.4-3.0) at <35 weeks' gestation than did control women. Compared with control women those with chronic hypertension had higher rates of indicated preterm delivery at both <37 weeks' gestation (21.9% vs 3.4%; odds ratio, 8.1; 95% confidence interval, 6.2-10.6) and at <35 weeks' gestation (12.1% vs 1.6%; odds ratio, 8.2; 95% confidence interval, 5.7-11.9), but there were no differences in rates of spontaneous preterm delivery. CONCLUSION: The increased rate of preterm delivery among women with chronic hypertension relative to control women was primarily an increase in indicated preterm delivery, whereas the rates of both spontaneous and indicated preterm delivery were increased among women with pregestational diabetes mellitus.

Adult↗
PubMed1999

Safety of labor epidural anesthesia for women with severe hypertensive disease. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: The aim of this study was to determine whether epidural anesthesia during labor increased the frequencies of cesarean delivery, pulmonary edema, and renal failure among women with severe hypertensive disease. STUDY DESIGN: We performed a secondary retrospective analysis of a subgroup population within a multicenter double-blind trial of low-dose aspirin therapy for women at high risk for development of preeclampsia. Subjects in whom severe hypertensive disease developed were selected. The primary outcomes were the overall frequencies of cesarean delivery among women with severe hypertensive disease who had labor with and without epidural anesthesia. Other maternal and neonatal outcomes were also compared between women who did and did not receive epidural anesthesia. RESULTS: Among the women with severe hypertensive disease (n = 444) 327 had labor. Among the women with severe disease who had labor there was no difference in either the overall cesarean delivery rate (32.1% vs 28.0%; P =.44) or the rate of cesarean delivery for fetal distress or failure to progress (27.8% vs 22.0%; P =.26) between women who did and did not receive epidural analgesia. Women with chronic hypertension were more likely to have a cesarean delivery overall if they received epidural anesthesia, but there was otherwise no difference in the frequencies of cesarean delivery for these indications between women with and without epidural anesthesia within each of the high-risk groups. Pulmonary edema was rare and acute renal failure did not develop in any women. CONCLUSION: Epidural anesthesia use did not increase the frequencies of cesarean delivery, pulmonary edema, and renal failure among women with severe hypertensive disease.

Adult↗
PubMed1999

The preterm prediction study: effect of gestational age and cause of preterm birth on subsequent obstetric outcome. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: We sought to evaluate the association between prior spontaneous preterm delivery and subsequent pregnancy outcome. STUDY DESIGN: A total of 1711 multiparous women with singleton gestations were prospectively evaluated at 23 to 24 weeks' gestation. Prior pregnancies were coded for the presence or absence of a prior spontaneous preterm delivery. If a prior spontaneous preterm delivery had occurred, the gestation of the earliest prior delivery (13-22, 23-27, 28-34, and 35-36 weeks' gestation) was recorded. Current gestations were categorized as spontaneous preterm delivery at <28, <30, <32, <35, or <37 weeks' gestation. The risk of spontaneous preterm delivery in the current gestation was determined on the basis of the occurrence, gestational age, and cause of the earliest prior spontaneous preterm delivery. RESULTS: The incidences of spontaneous preterm delivery before 28, 30, 32, 35, and 37 weeks' gestation were 0.8%, 1.1%, 1.9%, 5.1%, and 11.9%, respectively. Those with a prior spontaneous preterm delivery carried a 2.5-fold increase in the risk of spontaneous preterm delivery in the current gestation over those with no prior spontaneous preterm delivery (21. 7% vs 8.8%; P </=.001). Gravid women with an early prior spontaneous preterm delivery (23-27 weeks' gestation) had a higher risk of recurrent spontaneous preterm delivery (27.1% vs 8.8%; P </=.001). Prior spontaneous preterm delivery was more closely associated with subsequent early spontaneous preterm delivery at <28 weeks' gestation (relative risk, 10.6) than for spontaneous preterm delivery overall (relative risk, 2.5). An early prior spontaneous preterm delivery (23-27 weeks' gestation) was most highly associated with early spontaneous preterm delivery (<28 weeks' gestation) in the current gestation (relative risk, 22.1). The relationship between prior spontaneous preterm delivery and current outcome was not as strong for those with a very early spontaneous preterm delivery (13-22 weeks' gestation). Prior spontaneous preterm delivery caused by preterm premature rupture of the membranes and preterm labor was significantly associated with similar outcomes in the current gestation (P <.001). CONCLUSION: Prior spontaneous preterm delivery is highly associated with recurrence in the current gestation. An early prior spontaneous preterm delivery is more predictive of recurrence and is most highly associated with subsequent early spontaneous preterm delivery.

Adult↗
PubMed1999

Obstetric determinants of neonatal survival: antenatal predictors of neonatal survival and morbidity in extremely low birth weight infants.

OBJECTIVE: The aim of the study was to compare clinical and ultrasonographic variables obtained before delivery as predictors of neonatal survival and morbidity in infants weighing </=1000 g at birth. STUDY DESIGN: Maternal data available before the birth of singleton infants with birth weights </=1000 g who were delivered at the 11 tertiary perinatal centers of the National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Research Units were studied. Births that followed extramural delivery, antepartum stillbirths, multiple gestations, induced abortions, infants with major malformations, and fetuses delivered at <20 weeks' gestation were excluded. Ultrasonographic variables, including estimated fetal weight, obstetrically estimated gestational age, femur length, and biparietal diameter, and clinical variables, such as maternal race, antenatal care, substance abuse, medical treatment, reason for delivery, fetal gender, and presentation, were studied with logistic regression as predictors of neonatal outcome, including intrapartum stillbirth, neonatal death, and survival to 120 days after birth or to discharge from the hospital with or without the presence of markers of major morbidity. RESULTS: Eight hundred eight infants met enrollment criteria; 63 were excluded because of incomplete data and 32 were excluded because of malformations, leaving 713 for analysis, 386 of whom had an ultrasonographic examination within 3 days of delivery that recorded femur length, biparietal diameter, and estimated fetal weight. Forty-two percent of births were the result of preterm labor, 22% were the result of preterm ruptured membranes, 12% were the result of preeclampsia or eclampsia, 9% were the result of fetal distress, 4% were the result of placenta previa or abruptio placentae, and 2% were the result of intrauterine growth restriction. Perinatal mortality before 24 weeks' gestation exceeded 81% (19% stillbirths and 62% neonatal deaths) but declined sharply thereafter. Most survivors born before 26 weeks' gestation had serious morbidity. Fetal femur length and estimated gestational age predicted survival better than did biparietal diameter or estimated fetal weight. Infants who survived with markers of serious long-term morbidity could not be distinguished from those who survived without morbidity markers before delivery by ultrasonography or clinical data. Threshold values for ultrasonographic measurements of biparietal diameter and femur length were developed to distinguish fetuses with no chance of survival. CONCLUSION: Ultrasonographic assessment of either fetal femur length or gestational age predicts neonatal mortality better than do other antenatal tests. No tests accurately predicted neonatal morbidity in infants weighing </=1000 g at birth.

Female↗
PubMed1999

The preterm prediction study: failure of midtrimester cervical sialidase level elevation to predict subsequent spontaneous preterm birth.

OBJECTIVE: Our objective was to determine any associations among midtrimester cervical fluid sialidase activity, bacterial vaginosis, and subsequent spontaneous preterm birth. STUDY DESIGN: In this nested case-control study all patients (n = 126) with spontaneous preterm birth at <35 weeks' gestation and selected control subjects delivered at >/=37 weeks' gestation (n = 126, matched for race, parity, and center) were derived from women enrolled in the multicenter National Institute of Child Health and Human Development Preterm Prediction Study. Sialidase activity and presence of bacterial vaginosis according to Gram stain were determined in cervical swabs and vaginal smears, respectively, obtained at 22 weeks' to 24 weeks 6 days' gestation. RESULTS: The mean +/- SD sialidase activities were similar in case patients and control subjects (0.64 +/- 1.60 vs 0.41 +/- 0.94 nmol. mL-1. min-1, P =.21). Neither sialidase activity above the 90th percentile (10.3% vs 9.5%, P =.8) nor sialidase activity above the 95th percentile (7.9% vs 4. 8%, P =.3) of control specimens (>1.43 and >2.23 nmol. mL-1. min-1, respectively) was associated with spontaneous preterm birth. The frequency of combinations of bacterial vaginosis and elevated sialidase activity was similar (P >/=.63 with either cutoff) in case patients and control subjects. Sialidase activity was significantly higher among women with bacterial vaginosis than among those without bacterial vaginosis (1.35 +/- 1.87 vs 0.03 +/- 0.14 nmol. mL-1. min-1, P <.0001). CONCLUSIONS: Elevated cervical fluid sialidase activity at 22 to 24 weeks' gestation did not distinguish women at increased risk for spontaneous preterm birth, nor did it discriminate a subgroup of patients who had bacterial vaginosis associated with spontaneous preterm birth.

Case-Control Studies↗
PubMed1998

The preterm prediction study: risk factors for indicated preterm births. Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development.

OBJECTIVE: Preterm births occur for many different reasons. Most efforts to identify risk factors for preterm births either ignore cause and consider preterm births as a single entity or examine risk factors for spontaneous preterm births. We performed this study to examine risk factors for indicated preterm births, which constitute more than one quarter of all preterm births. STUDY DESIGN: The study included 2929 women evaluated at 24 weeks' gestation at 10 centers. Information was gathered about demographic factors, socioeconomic status, home and work environments, drug and alcohol use, and medical history. In addition vaginal samples were evaluated for fetal fibronectin and bacterial vaginosis and cervical length was measured by transvaginal ultrasonography. Associations with indicated preterm birth were evaluated by univariate tests and by multivariable analysis with logistic regression. RESULTS: Of the women studied at 24 weeks' gestation 15.3% were delivered of their infants at <37 weeks' gestation. Of these deliveries, 27.7% were indicated preterm births. Risk factors in the final multivariable model were, in order of decreasing odds ratios, mullerian duct abnormality (odds ratio 7.02), proteinuria at <24 weeks' gestation (odds ratio 5.85), history of chronic hypertension (odds ratio 4.06), history of previous indicated preterm birth (odds ratio 2.79), history of lung disease (odds ratio 2.52), previous spontaneous preterm birth (odds ratio 2.45), age >30 years (odds ratio 2.42), black ethnicity (odds ratio 1.56), and working during pregnancy (odds ratio 1.49). Alcohol use in pregnancy was actually associated with a lower risk of indicated preterm birth (odds ratio 0.35). CONCLUSION: The risk factors found in this analysis tend to be different from those associated with spontaneous preterm birth.

Adolescent↗
PubMed1998

The Preterm Prediction Study: recurrence risk of spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: We sought to estimate the risk of spontaneous preterm birth in parous women by use of obstetric history, fetal fibronectin, and sonographic cervical length. STUDY DESIGN: The probability of spontaneous preterm birth before 35 weeks' gestation was estimated from a logistic regression model with data from 1282 parous women analyzed according to gestational age at the most recent prior delivery (prior preterm birth at 18 to 26 weeks, 27 to 31 weeks, 32 to 36 weeks, and > or = 37 weeks' gestation), fetal fibronectin status (positive = > or = 50 ng/dl), and cervical length by percentile groups (< or = 10th = < or = 25 nm, 10th to 50th = 26 to 35 mm, and > 50th = > 35 mm) measured at 22 to 24 weeks' gestation. Fibronectin and cervical length results were blinded for clinical care. RESULTS: Among fetal fibronectin positive women with a prior preterm birth, the estimated recurrence risk of preterm birth < 35 weeks' gestation was approximately 65% when the cervix was < or = 25 mm, 45% when the cervix was 26 to 35 mm, and 25% when the cervix was > 35 mm at 24 weeks' gestation. For fetal fibronectin negative women with a prior preterm birth, the recurrence risk was 25% when the cervix was < or = 25 mm, 14% when the cervix was 26 to 35 mm, and 7% when the cervix was > 35 mm. The risk of preterm birth was increased among women with a history of preterm delivery but was not influenced by the gestational age at delivery of the most recent preterm birth. CONCLUSION: The recurrence risk of spontaneous preterm birth varies widely according to fetal fibronectin and cervical length. Cervical length and fetal fibronectin results had distinct and significant effects on the recurrence risk of preterm birth. Predicted recurrence risk is increased by twofold to fourfold in women with a positive compared with a negative fetal fibronectin, and it increases as cervical length shortens in both fetal fibronectin-positive and fetal fibronectin-negative women. These data may be useful to care for women with a history of preterm birth and to design studies to prevent recurrent premature delivery.

Adult↗