The Alabama preterm birth prevention project

R L Goldenberg; Davis RO; R L Copper; Corliss DK; Andrews JB; Carpenter AH

Pregnancy · Preterm Birth

The Alabama preterm birth prevention project

Goldenberg RL, Davis RO, Copper RL, Corliss DK, Andrews JB, Carpenter AH

Published June 1990 Obstetrics and Gynecology, 75(6), 933-939

PMID 2342740

Abstract

A preterm birth prevention program consisting of risk scoring, intensive weekly observation including cervical examinations, and detailed education about preterm labor signs and symptoms was tested in a predominantly black, indigent population. One thousand high-risk women were randomized to treatment or control groups. Although more preterm labor was diagnosed and treated in the treatment group, there were no significant differences between the groups with respect to mean birth weight or gestational age, spontaneous preterm delivery rates, or low or very low birth weight rates. The rates of respiratory distress syndrome and fetal and neonatal mortality, although greater in the treatment group, were not statistically different. However, the treatment-group infants had significantly more intracranial hemorrhages and spent more days on ventilators. At this institution, the preterm birth prevention program was not effective.

Topics

By this author

Preterm Birth · Tocolytic Therapy

Prevention of premature birth

Goldenberg RL et al., 1998 N Engl J Med

Preterm birth, which occurs in 11 percent of all pregnancies, is responsible for the majority of neonatal deaths and nearly one half of all cases of congenital neurologic disability, including cerebral palsy.1Although all births before 37 weeks of gestation are considered premature, births before 32 weeks' gestation (2 percent of all births) account for most neonatal deaths and disorders.2 State and national vital statistics indicate that the incidence of preterm birth has risen over the past 15 years (Figure 1), and it remains twice as high among black women as among white women.35 Preterm birth is commonly categorized . . .

Preterm Birth · Prediction

The preterm prediction study: the value of new vs standard risk factors in predicting early and all spontaneous preterm births. NICHD MFMU Network

Goldenberg RL et al., 1998 Am J Public Health

This study was undertaken to determine the relationship between fetal fibronectin, short cervix, bacterial vaginosis, other traditional risk factors, and spontaneous preterm birth. From 1992 through 1994, 2929 women were screened at the gestational age 22 to 24 weeks. The odds ratios for spontaneous preterm birth were highest for fetal fibronectin, followed by a short cervix and history of preterm birth. These factors, as well as bacterial vaginosis, were more strongly associated with early than with late spontaneous preterm birth. Bacterial vaginosis was more common--and a stronger predictor of spontaneous preterm birth--in Black women, while body mass index less than 19.8 was a stronger predictor in non-Black women. This analysis suggests a pathway leading from Black race through bacterial vaginosis and fetal fibronectin to spontaneous preterm birth. Prior preterm birth is associated with spontaneous preterm birth through a short cervix. Fetal fibronectin and a short cervix are stronger predictors of spontaneous preterm birth than traditional risk factors. Bacterial vaginosis was found more often in Black than in non-Black women and accounted for 40% of the attributable risk for spontaneous preterm birth at less than 32 weeks.

Preterm Birth · Prediction

The preterm prediction study: fetal fibronectin testing and spontaneous preterm birth. NICHD Maternal Fetal Medicine Units Network

Goldenberg RL et al., 1996 Obstet Gynecol

To evaluate the presence of fetal fibronectin in the cervix and vagina as a screening test for spontaneous preterm birth. Two thousand nine hundred twenty-nine women at ten centers were routinely screened every 2 weeks from 22-24 to 30 weeks for cervical and vaginal fetal fibronectin. A positive test was defined as a value equal to or greater than 50 ng/mL. The relation between a positive test at four gestational ages and spontaneous preterm birth at various intervals after the test was determined. In each testing period, 3-4% of the fetal fibronectin tests were positive. The correlation between cervical and vaginal fetal fibronectin at the same visit was always approximately 0.7 (P < .001), and that between cervical or vaginal fetal fibronectin in consecutive visits was between 0.17 and 0.25 (P < .001). The sensitivity of fetal fibronectin at 22-24 weeks to predict spontaneous preterm birth at less than 28 weeks was 0.63, and the relative risk for a positive versus negative test was 59. The specificity was always 96-98%, whereas the positive predictive value rose from 13% to 36% as the upper limit of the definition of preterm birth was increased from less than 28 to less than 37 weeks. The relative risk for spontaneous preterm birth after a positive fetal fibronectin test compared with a negative fetal fibronectin test varied substantially by testing period and by the definition of spontaneous preterm birth, but always remained greater than 4 and statistically significant. A positive cervical or vaginal fetal fibronectin test at 22-24 weeks predicted more than half of the spontaneous preterm births at less than 28 weeks (sensitivity 0.63). As the definition of spontaneous preterm birth was extended to include later gestational ages or when the fetal fibronectin test was performed later in pregnancy, the level of association between a positive fetal fibronectin test and spontaneous preterm birth, while remaining highly significant, tended to decrease. Although fetal fibronectin is an excellent test for predicting spontaneous preterm birth, we present no evidence that the use of this test will result in a reduction in spontaneous preterm birth.

Cervical Conditions · Cervical Insufficiency

The length of the cervix and the risk of spontaneous premature delivery. National Institute of Child Health and Human Development Maternal Fetal Medicine Unit Network

Iams JD et al., 1996 N Engl J Med

The role of the cervix in the pathogenesis of premature delivery is controversial. In a prospective, multicenter study of pregnant women, we used vaginal ultrasonography to measure the length of the cervix; we also documented the incidence of spontaneous delivery before 35 weeks' gestation. At 10 university-affiliated prenatal clinics, we performed vaginal ultrasonography at approximately 24 and 28 weeks of gestation in women with singleton pregnancies. We then assessed the relation between the length of the cervix and the risk of spontaneous preterm delivery. We examined 2915 women at approximately 24 weeks of gestation and 2531 of these women again at approximately 28 weeks. Spontaneous preterm delivery (at less than 35 weeks) occurred in 126 of the women (4.3 percent) examined at 24 weeks. The length of the cervix was normally distributed at 24 and 28 weeks (mean [+/- SD], 35.2 +/- 8.3 mm and 33.7 +/- 8.5 mm, respectively). The relative risk of preterm delivery increased as the length of the cervix decreased. When women with shorter cervixes at 24 weeks were compared with women with values above the 75th percentile, the relative risks of preterm delivery among the women with shorter cervixes were as follows: 1.98 for cervical lengths at or below the 75th percentile (40 mm), 2.35 for lengths at or below the 50th percentile (35 mm), 3.79 for lengths at or below the 25th percentile (30 mm), 6.19 for lengths at or below the 10th percentile (26 mm), 9.49 for lengths at or below the 5th percentile (22 mm), and 13.99 for lengths at or below the 1st percentile (13 mm) (P < 0.001 for values at or below the 50th percentile; P = 0.008 for values at or below the 75th percentile). For the lengths measured at 28 weeks, the corresponding relative risks were 2.80, 3.52, 5.39, 9.57, 13.88, and 24.94 (P < 0.001 for values at or below the 50th percentile; P = 0.003 for values at the 75th percentile). The risk of spontaneous preterm delivery is increased in women who are found to have a short cervix by vaginal ultrasonography during pregnancy.

Related research

Preterm Birth · Prediction

The effectiveness of preterm-birth prevention educational programs for high-risk women: a meta-analysis

Hueston WJ et al., 1995 Obstet Gynecol

To evaluate whether preterm-birth prevention educational programs are effective at reducing neonatal mortality, low birth weight (LBW), and preterm delivery. A MEDLINE literature search of English-language studies was performed, supplemented by a bibliography search of original research and review articles to locate studies assessing preterm-birth prevention programs. We identified 31 studies that reported results from trials evaluating preterm-birth prevention programs. From this group, only the six randomized controlled trials evaluating preterm-birth prevention education programs satisfied criteria of homogeneity to be included in a meta-analysis. One of these six studies was a subset of another study and was excluded except when reporting outcomes that were not included in the larger report. Two independent reviewers assessed study methodology and identified the following outcomes: LBW frequency, preterm birth frequency, neonatal survival, birth weight, gestational age at delivery, and preterm labor diagnosis rates. When data were combined using meta-analytic techniques, no significant benefits were found for preterm-birth education programs in preventing neonatal death (cumulative relative risk [RR] 1.00, 95% confidence interval [CI] 0.99-1.01), LBW rates (RR 0.99, 95% CI 0.88-1.11), or preterm delivery rates (RR 1.08, 95% CI 0.92-1.27). The only statistically significant effect of preterm birth education programs appears to be an increase in the frequency at which preterm labor is diagnosed (RR 1.71, 95% CI 1.41-2.08). Preterm-birth prevention educational programs appear to have little benefit in reducing preterm birth and may result in an increased rate of diagnosis of preterm labor.

Preterm Birth · Prediction

The West Los Angeles Preterm Birth Prevention Project. I. Program impact on high-risk women

Hobel CJ et al., 1994 Am J Obstet Gynecol

The primary objective of this prospective study was to test whether preterm birth prevention education plus increased clinic visits and selected prophylactic interventions reduce preterm birth. Eight West Los Angeles prenatal county clinics, comparable with respect to selected demographics, were randomized to be either experimental or control clinics. High-risk patients in all clinics were identified with a risk scoring system derived from a similar population. High-risk patients (N = 1774) in experimental clinics were offered a program of education and more frequent visits and were randomized to receive various secondary intervention protocols in addition to the basic interventions of education and more frequent visits. Control clinic patients (N = 880) received standard county care. Preterm birth rates were 19% lower among the experimental high-risk patients (7.4% vs 9.1%), and differences were significant (p < 0.05) when preterm risk was taken into account. There was no evidence to suggest that the secondary interventions provided added benefit over the primary intervention protocol of preterm birth prevention education and increased visits. The 19% reduction in preterm birth rate observed in the experimental clinics suggest an overall program benefit from a protocol that offered education, more frequent visits, and greater attention given to patients while the selected interventions were applied.

Preterm Birth · Prediction

Monitoring women at risk for preterm labor

Dyson DC et al., 1998 N Engl J Med

Preterm birth is a major cause of perinatal morbidity and mortality. Whether the rate of preterm birth can be reduced by frequent contact between nurses and pregnant women or home monitoring of uterine activity is not known. We randomly assigned 2422 pregnant women with known risk factors for preterm labor (including 844 women who were pregnant with twins) to receive education and to have one of the following: weekly contact with a nurse, daily contact with a nurse, or daily contact with a nurse and home monitoring of uterine activity. The nurses elicited the women's own assessments of their symptoms and signs of preterm labor. The primary end point was the incidence of birth at less than 35 weeks' gestation. Secondary end points included cervical status at the time preterm labor was diagnosed and birth weight. There were no significant differences among the groups in the incidence of birth at less than 35 weeks (14 percent in the weekly-contact group, 13 percent in the daily-contact group, and 14 percent in the home-monitoring group), in the mean amount of cervical dilatation at the time preterm labor was diagnosed (1.8 cm, 1.5 cm, and 1.4 cm, respectively), or in such neonatal outcomes as birth weights of less than 1500 g or less than 2500 g. However, daily contact with a nurse increased the mean number of unscheduled visits to obstetricians (1.2 in the weekly-contact group, 1.8 in the daily-contact group, and 2.3 in the home-monitoring group) and the proportion of women who received prophylactic tocolytic drugs (12 percent, 14 percent, and 19 percent, respectively). Women who have daily contact with a nurse, with or without home monitoring of uterine activity, have no better pregnancy outcomes than women who have weekly contact with a nurse.

Preterm Birth · Prediction

Prevention of preterm birth in high-risk patients: the role of education and provider contact versus home uterine monitoring

Dyson DC et al., 1991 Am J Obstet Gynecol

A total of 394 patients were enrolled in a study to assess the effectiveness of an educational preterm delivery prevention program and to determine whether the addition of home uterine monitoring to the program improved results in patients at high risk of preterm labor. Both the educational program and home uterine monitoring were found to increase the percentage of women with preterm labor who sought care while still favorable for long-term suppression, resulting in a decreased incidence of preterm births and improved outcome when compared with similar high-risk patients who did not participate in these programs. In a randomized, prospective study, addition of home uterine monitoring to the educational program was found to significantly improve outcome in twin gestations but not in singleton gestations. However, the number of singleton pregnancies was too small to rule out possible benefit from home uterine monitoring in that group.

Pregnancy › Preterm Birth › Prediction · Birth and Delivery › Birth Outcomes › Maternal Morbidity

PMID 2342740 2342740 Goldenberg et al. 1990, Goldenberg 1990

Cite this article

Goldenberg, R. L., Davis, R. O., Copper, R. L., Corliss, D. K., Andrews, J. B., & Carpenter, A. H. (1990). The Alabama preterm birth prevention project. Obstetrics and gynecology, 75(6), 933-939.

Keywords

Adolescent, Adult, Age Factors, Alabama, Female, Humans, Infant, Newborn, Infant, Newborn, Diseases, Obstetric Labor, Premature/complications/prevention & Control, Parity, Pregnancy, Prenatal Care, Racial Groups, Risk Factors