A randomized trial of nurse intervention to reduce preterm and low birth weight births

Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate

Meis PJ et al., 2003 · N Engl J Med

Women who have had a spontaneous preterm delivery are at greatly increased risk for preterm delivery in subsequent pregnancies. The results of several small trials have suggested that 17 alpha-hydroxyprogesterone caproate (17P) may reduce the risk of preterm delivery. We conducted a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery. Women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation and randomly assigned by a central data center, in a 2:1 ratio, to receive either weekly injections of 250 mg of 17P or weekly injections of an inert oil placebo; injections were continued until delivery or to 36 weeks of gestation. The primary outcome was preterm delivery before 37 weeks of gestation. Analysis was performed according to the intention-to-treat principle. Base-line characteristics of the 310 women in the progesterone group and the 153 women in the placebo group were similar. Treatment with 17P significantly reduced the risk of delivery at less than 37 weeks of gestation (incidence, 36.3 percent in the progesterone group vs. 54.9 percent in the placebo group; relative risk, 0.66 [95 percent confidence interval, 0.54 to 0.81]), delivery at less than 35 weeks of gestation (incidence, 20.6 percent vs. 30.7 percent; relative risk, 0.67 [95 percent confidence interval, 0.48 to 0.93]), and delivery at less than 32 weeks of gestation (11.4 percent vs. 19.6 percent; relative risk, 0.58 [95 percent confidence interval, 0.37 to 0.91]). Infants of women treated with 17P had significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen. Weekly injections of 17P resulted in a substantial reduction in the rate of recurrent preterm delivery among women who were at particularly high risk for preterm delivery and reduced the likelihood of several complications in their infants.

Too Soon to Adopt Progesterone for the Prevention of Preterm Delivery

Meis PJ et al., 2003

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.

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.

Prevention of preterm birth. Role of daily telephone contact

Boehm FH et al., 1996 · J Reprod Med

To compare the effectiveness of routine management of patients at high risk for preterm delivery to the effectiveness of routine management in combination with daily telephone nursing contact. The control group, 1 (n = 21), had education and frequent prenatal visits and cervical examinations. The study group, 2 (n = 21), had education, frequent prenatal visits and cervical examination, and daily telephone contact. Group 3 (n = 22) received education but refused to participate. There were no significant differences (SD) between groups in race, smoking, age, multiple gestation, visits, diagnosis of premature labor, mean days gained after diagnosis of premature labor, tocolytic use or bed rest. There was also no SD in preterm birth rate, mode of delivery, number of maternal or neonatal hospital days, mean neonatal weight or gestational age at delivery between groups. While not reducing the overall incidence of preterm birth, this management for all groups resulted in a more advanced gestational age at the time of delivery (mean change = 7.5 weeks, P < .0001) when compared to the patient's first preterm birth. This study indicated that daily contact, while providing reassurance and support, did not change the outcome when the study group was compared to women managed similarly but without daily contact.

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.

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.

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.