Impact of the "39-week rule" on adverse pregnancy outcomes: a statewide analysis.

BACKGROUND: The "39-week rule," adopted by the American College of Obstetricians and Gynecologists circa 2009, discouraged routine elective induction of labor in early-term gestations (37 weeks 0 days-38 weeks 6 days) to decrease the risk of adverse neonatal outcomes. However, little research exists regarding any unintended adverse pregnancy outcomes associated with this policy shift. OBJECTIVE: This study aimed to quantify the difference in incidence of adverse pregnancy outcomes before and after the implementation of the 39-week rule. STUDY DESIGN: Deidentified data from all births in the state of South Carolina from 2000 to 2008 (before the 39-week rule) and from 2013 to 2017 (after statewide implementation and enforcement of the rule) were obtained from the South Carolina Revenue and Fiscal Affairs Office. Demographic data and International Classification of Diseases 9/10 codes were obtained for each birth. Our primary outcome was the incidence of any of the following adverse pregnancy outcomes: cesarean delivery, hypertensive disorders, chorioamnionitis, postpartum hemorrhage, high-degree lacerations, placental abruption, and intensive care unit admission. Propensity score analysis was used to control for age, body mass index, and race. After stratification by propensity score, the Cochran-Mantel-Haenszel test was used to compare the prerule and postrule groups. RESULTS: A total of 633,985 births were eligible for inclusion-412,632 from 2000 to 2008, and 221,353 from 2013 to 2017. There was a significant increase in the primary outcome in the postrule period (39.94% pre vs 42.76% post; P<.01). The incidence of all hypertensive disorders was significantly increased in the postrule period compared with the prerule period (7.75% pre vs 10.1% post; P<.01). The incidence of chorioamnionitis and cesarean delivery also increased in the postrule period (1.45% pre vs 1.92% post; P<.01; 29.6% pre vs 31.82% post; P<.01; respectively). CONCLUSION: There was a significant increase in the primary outcome following the implementation of the 39-week rule. Although the policy shift was driven by a desire to decrease adverse neonatal outcomes, aggregate benefit was not observed for pregnancy outcomes.

Impact of restricting early-term deliveries on adverse neonatal outcomes: a statewide analysis.

BACKGROUND: The "39-Week Rule" was adopted by the American College of Obstetricians and Gynecologists in 2009 to eliminate nonmedically indicated (elective) deliveries before 39 weeks in an effort to improve neonatal outcomes. OBJECTIVE: Our primary objective was to quantify the effect of this policy change on adverse neonatal outcomes among a cohort of term births in South Carolina. STUDY DESIGN: Deidentified data from all births in the state of South Carolina from 2000 to 2008 (before the 39-week rule) and from 2013 to 2017 (after statewide implementation and enforcement of the rule) were obtained from the South Carolina Revenue and Fiscal Affairs Office. Demographic data and International Statistical Classification of Diseases and Related Health Problems Ninth/Tenth Revision codes were obtained for each birth. Our primary outcome was admission to a neonatal intensive care unit. Our secondary outcomes were respiratory morbidities (including respiratory distress syndrome and transient tachypnea of the newborn), hypoxic-ischemic encephalopathy, seizure, sepsis, birth injuries, hyperbilirubinemia, hypoglycemia, and feeding difficulties. Propensity score analysis was used to control for maternal age, body mass index, race, gestational hypertension, infection, placental abruption, and gestational and pregestational diabetes mellitus. After stratification by propensity score, the Cochran-Mantel-Haenszel test was used to compare groups. RESULTS: A total of 620,121 infants were liveborn at term during the 2 study periods. After implementation of the 39-week rule, there was a significant reduction in early-term deliveries. In adjusted analyses, neonatal intensive care unit admission was significantly more common in the postimplementation period. Respiratory morbidities were also significantly more common postimplementation. In contrast, there were significant reductions in birth injuries and hyperbilirubinemia in the postimplementation period. CONCLUSION: Implementation of the 39-week rule was associated temporally with an increase in adverse neonatal outcomes. The outcomes intended to be reduced by the 39-week rule, including neonatal intensive care unit admission and respiratory morbidity, seem to have increased in incidence despite adherence to the proposed guidelines.

Microbiomes of Site-Specific Dental Plaques from Children with Different Caries Status.

The oral microbiota associated with the initiation and progression of dental caries has yet to be fully characterized. The Human Oral Microbe Identification Using Next-Generation Sequencing (HOMINGS) approach was used to analyze the microbiomes of site-specific supragingival dental plaques from children with different caries status. Fifty-five children (2 to 7 years of age) were assessed at baseline and at 12 months and grouped as caries free (CF), caries active with enamel lesions (CAE), and caries active with dentin carious lesions (CA). Plaque samples from caries-free tooth surfaces (PF) and from enamel carious lesions (PE) and dentin carious lesions (PD) were collected. 16S community profiles were obtained by HOMINGS, and 408 bacterial species and 84 genus probes were assigned. Plaque bacterial communities showed temporal stability, as there was no significant difference in beta diversity values between the baseline and 12-month samples. Irrespective of collection time points, the microbiomes of healthy tooth surfaces differed substantially from those found during caries activity. All pairwise comparisons of beta diversity values between groups were significantly different (P < 0.05), except for comparisons between the CA-PF, CAE-PE, and CA-PE groups. Streptococcus genus probe 4 and Neisseria genus probe 2 were the most frequently detected taxa across the plaque groups, followed by Streptococcus sanguinis, which was highly abundant in CF-PF. Well-known acidogenic/aciduric species such as Streptococcus mutans, Scardovia wiggsiae, Parascardovia denticolens, and Lactobacillus salivarius were found almost exclusively in CA-PD. The microbiomes of supragingival dental plaque differ substantially among tooth surfaces and children of different caries activities. In support of the ecological nature of caries etiology, a steady transition in community species composition was observed with disease progression.