EVIDENCE-BASED ANSWER
Yes, it may decrease preterm births, especially among higher-risk women—minority women, women of low socioeconomic status, and adolescents (strength of recommendation [SOR]: B, 1 randomized, controlled trial [RCT] and 1 matched cohort study).
Evidence summary
The evidence supporting improved health outcomes resulting from group prenatal care is limited. We found 1 RCT,1 1 matched-cohort study,2 and several pilot studies with descriptive analysis.3-5 All data sets used a trademarked group prenatal care model, CenteringPregnancy. The TABLE summarizes the outcomes of group and individual prenatal care reported in the studies.
Fewer preterm births
One large, unblinded RCT investigated the effect of group prenatal care on a cohort of young, mostly minority women of low economic status. Women who received group prenatal care had fewer preterm births than those who received traditional care (number needed to treat [NNT]=25; P=.045).1
A single cohort study compared pregnant teenagers enrolled in the CenteringPregnancy program with 2 clinic convenience samples. The group care recipients had significantly lower preterm delivery rates (NNT=7; P<.02).3 The study design, and therefore the detected relationship of group care to pregnancy-associated outcomes, may be particularly subject to selection bias.
Birth weight data are inconsistent
The matched cohort study recorded higher birth weights among infants born to mothers in group prenatal care.2 Subset analysis of preterm infants born to mothers in group care showed average birth weights approximately 400 g higher than those in individual care (P<.05).2 The RCT, however, found no clinically or statistically significant differences in birth weights between intervention and control groups.1
TABLE
Pregnancy outcomes: Group vs individual prenatal care
| STUDY | STUDY DESIGN | OUTCOMES: GROUP VS INDIVIDUAL PRENATAL CARE | OR (95% CI) | NNT |
|---|---|---|---|---|
| Ickovics JR et al.1 | RCT N=1047 | Preterm births | 0.67 (0.44-0.98) | 25 |
| Preterm births in African American women | 0.59 (0.38-0.92) | 17 | ||
| Breastfeeding initiation | 1.73 (1.28-2.35) | 8 | ||
| Less-than-adequate prenatal care* | 0.68 (0.50-0.91) | 16 | ||
| RESULTS (P VALUE) | ||||
| Ickovics JR et al.2 | Matched cohort N=458 | Birth weight (g) | 3228 vs 3159 (P<.01) | — |
| Preterm birth weight (g) | 2398 vs 1990 (P<.05) | — | ||
| Grady MA et al.3 | Cohort study with clinic comparison N=124 (intervention) | Preterm births <37 wk (%) | 10.5 vs 25.7 (P<.02) | 7 |
| Low birth weight <2500 g (%) | 8.8 vs 22.9 (P<.02) | 7 | ||
| Breastfeeding at hospital discharge (%) | 46 vs 28 (P<.02) | 6 | ||
| Rising SS4 | Descriptive analysis N=111 | 3rd trimester emergency room visits (%) | 26 vs 74 (P=.001) | 2 |
| Baldwin KA5 | 2-group pre-/post-test design N=98 | Change in prenatal knowledge scores† | 0.98 vs 0.4 (P=.03) | — |
| CI, confidence interval; NN T, number needed to treat; OR, odds ratio. | ||||
| *Kotelchuck Adequacy of Prenatal Care Utilization Index, a validated scoring scale encompassing timing of initiation of care, number of visits, and quality and content of prenatal care. Kotelchuck M. An evaluation of the Kessner Adequacy of Prenatal Care Index and the proposed Adequacy of Prenatal Care Utilization Index. Am J Public Health. 1994;84:1414-1420. | ||||
| †Patient Participation and Satisfaction questionnaire. Littlefield V, Adams B. Patient participation in alternative perinatal care: impact on satisfaction and health locus of control. Res Nurs Health. 1987;10:139-148. | ||||