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Impact of fetal inflammatory response on the severity of necrotizing enterocolitis in preterm infants

OBJECTIVE

Neonates born with fetal inflammatory response (FIR) are at increased risk for adverse neonatal outcomes. Our objective was to determine whether FIR and its severity is associated with severity of necrotizing enterocolitis (NEC) in preterm infants.

METHODS

A case-control retrospective study of infants <33 weeks gestational age or <1500 g birthweight, including 260 with stage I-III NEC and 520 controls matched for gestational age. Placental pathology was evaluated, and FIR progression and its severity were defined according to Amsterdam classification.

RESULTS

In this study, mild FIR (i.e., stage 1 FIR) was present in 52 controls (10.0%) and 22 infants with stage I-III NEC (8.5%), while moderate to severe FIR (i.e., ≥stage 2 FIR) was present in 16 controls (3.1%) and 47 infants with stage I-III NEC (18.1%). Both stage and grade of FIR were associated with stage of NEC (P < 0.001). On multinomial logistic regression, stage III NEC was associated with stage of FIR (P < 0.001).

CONCLUSION

This is the first report demonstrating the association between progression and increasing severity of FIR and stage of NEC.

IMPACT

Fetal Inflammatory Response (FIR) and its progression and severity are associated with the stages of necrotizing enterocolitis (NEC). This is the first study demonstrating the impact of progression and severity of FIR on stage III NEC. These observations provide additional insight into understanding the impact of intrauterine exposure to inflammation on the severity of NEC in preterm infants.

Development of a Prediction Model for Surgery or Early Mortality at the Time of Initial Assessment for Necrotizing Enterocolitis

OBJECTIVE

 No available scale, at the time of initial evaluation for necrotizing enterocolitis (NEC), accurately predicts, that is, with an area under the curve (AUC) ≥0.9, which preterm infants will undergo surgery for NEC stage III or die within a week.

STUDY DESIGN

 This is a retrospective cohort study (n = 261) of preterm infants with <33 weeks' gestation or <1,500 g birthweight with either suspected or with definite NEC born at Parkland Hospital between 2009 and 2021. A prediction model using the new HASOFA SCORE (H: yperglycemia, H: yperkalemia, use of inotropes for H: ypotension during the prior week, A: cidemia, Neonatal S: equential O: rgan F: ailure A: ssessment [nSOFA: ] score) was compared with a similar model using the nSOFA score.

RESULTS

 Among 261 infants, 112 infants had NEC stage I, 68 with NEC stage II, and 81 with NEC stage III based on modified Bell's classification. The primary outcome, surgery for NEC stage III or death within a week, occurred in 81 infants (surgery in 66 infants and death in 38 infants). All infants with pneumoperitoneum or abdominal compartment syndrome either died or had surgery. The HASOFA and the nSOFA scores were evaluated in 254 and 253 infants, respectively, at the time of the initial workup for NEC. Both models were internally validated. The HASOFA model was a better predictor of surgery for NEC stage III or death within a week than the nSOFA model, with greater AUC 0.909 versus 0.825, respectively, p < 0.001. Combining HASOFA at initial assessment with concurrent or later presence of abdominal wall erythema or portal gas improved the prediction surgery for NEC stage III or death with AUC 0.942 or 0.956, respectively.

CONCLUSION

 Using this new internally validated prediction model, surgery for NEC stage III or death within a week can be accurately predicted at the time of initial assessment for NEC.

KEY POINTS

· No available scale, at initial evaluation, accurately predicts which preterm infants will undergo surgery for NEC stage III or die within a week.. · In this retrospective cohort study of 261 preterm infants with either suspected or definite NEC we developed a new prediction model (HASOFA score).. · The HASOFA-model had high discrimination (AUC 0.909) and excellent calibration and was internally validated..

Impact of Size for Gestational Age on Multivariate Analysis of Factors Associated with Necrotizing Enterocolitis in Preterm Infants: Retrospective Cohort Study

OBJECTIVE

 Necrotizing enterocolitis (NEC) primarily affects preterm, especially small for gestational age (SGA), infants. This study was designed to (1) describe frequency and timing of NEC in SGA versus non-SGA infants and (2) assess whether NEC is independently associated with the severity of intrauterine growth failure.

STUDY DESIGN

 Retrospective cohort study of infants without severe congenital malformations born <33 weeks' gestational age (GA) carried out from 2009 to 2021. The frequency and time of NEC were compared between SGA and non-SGA infants. Multivariate logistic regression was used to assess whether NEC was independently associated with intrauterine growth restriction. Severe growth restriction was defined as birth weight Z-score <  -2.

RESULTS

 Among 2,940 infants, the frequency of NEC was higher in SGA than in non-SGA infants (25/268 [9.3%] vs. 110/2,672 [4.1%], respectively, p < 0.001). NEC developed 2 weeks later in SGA than non-SGA infants. In multivariate analysis, the adjusted odds of NEC increased with extreme prematurity (<28 weeks' GA) and with severe but not moderate growth restriction. The adjusted odds of NEC increased with urinary tract infection or sepsis within a week prior to NEC, were lower in infants fed their mother's own milk until discharge, and did not change over five epochs. NEC was independently associated with antenatal steroid (ANS) exposure in infants with birth weight (BW) Z-score < 0.

CONCLUSION

 NEC was more frequent in SGA than in non-SGA infants and developed 2 weeks later in SGA infants. NEC was independently associated with severe intrauterine growth failure and with ANS exposure in infants with BW Z-score < 0.

KEY POINTS

· We studied 2,940 infants <33 weeks' GA.. · We assessed NEC.. · NEC was more frequent in SGA infants.. · NEC occurred 2 weeks later in SGA infants.. · NEC was associated with severe growth restriction..

Association of Vaginal Progesterone Treatment With Prevention of Recurrent Preterm Birth

IMPORTANCE

Preterm birth (PTB) is the leading cause of infant morbidity and mortality worldwide. It has been suggested that vaginal progesterone (VP) treatment may reduce the recurrence of PTB.

OBJECTIVE

To evaluate the association of VP treatment with prevention of recurrent PTB among patients with a singleton pregnancy.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, observational cohort study, set in a public health care system for inner-city pregnant patients, enrolled patients with prior spontaneous PTB (gestational age, ≤35 weeks) receiving VP from May 15, 2017, to May 7, 2019. Patients who delivered between 1998 and 2011 served as a referent cohort matched 3:1 for obesity, race and ethnicity, and individual specific preterm birth history. Statistical analysis was performed from August 19, 2021, to September 2, 2022.

EXPOSURE

Patients received 90 mg of vaginal progesterone, 8%, nightly, initiated between 16 weeks and 0 days and 20 weeks and 6 days of pregnancy until 36 weeks and 6 days of pregnancy or delivery.

MAIN OUTCOMES AND MEASURES

The primary outcome was overall rate of recurrent PTB at 35 weeks or less of patients given VP compared with the 3:1 matched untreated historical controls. Secondary outcomes included assessment of PTB according to adherence (≥80% completing scheduled doses), duration of pregnancy relative to index gestational age, progesterone blood levels, and outcomes for those who declined VP.

RESULTS

A total of 417 patients (mean [SD] age, 30.4 [5.9] years; 64 Black patients [15.3%]; 272 [65.2%] with a body mass index of ≥30) received VP and were matched with 1251 controls (mean [SD] age, 28.8 [5.7] years; 192 Black patients [15.3%]; 816 [65.2%] with a body mass index of ≥30). The overall rate of recurrent PTB was 24.0% (100 of 417; 95% CI, 20.0%-28.4%) for the VP cohort compared with 16.8% (1394 of 8278) expected in the matched historical controls. Adherence was not associated with lower rates of recurrent PTB compared with nonadherence (odds ratio, 0.87 [95% CI, 0.51-1.41]). The mean difference between historical matched controls and those using VP was 0.2 weeks (95% CI, -1.4 to 1.0 weeks) without improvement in the interval of recurrent PTB after the implementation of VP (P = .73). Progesterone blood levels for patients who were adherent compared with those who were nonadherent were not significantly different at either 24 or 32 weeks (24 weeks: 99 ng/mL [95% CI, 85-121 ng/mL] vs 104 ng/mL [95% CI, 89-125 ng/mL]; P = .16; 32 weeks: 200 ng/mL [95% CI, 171-242 ng/mL] vs 196 ng/mL [95% CI, 155-271 ng/mL]; P = .69).

CONCLUSIONS AND RELEVANCE

This cohort study of patients with a current singleton pregnancy suggests that VP was not associated with a reduction in recurrent PTB.

A chronicle of the 17-alpha hydroxyprogesterone caproate story to prevent recurrent preterm birth

Preterm birth is a substantial public health concern. In 2019, the US preterm birth rate was 10.23%, which is the fifth straight year of increase in this rate. Moreover, preterm birth accounts for approximately 1 in 6 infant deaths, and surviving children often suffer developmental delay or long-term neurologic impairment. Although the burden of preterm birth is clear, identifying strategies to reduce preterm birth has been challenging. On October 29, 2019, a US Food and Drug Administration advisory committee voted 9 vs 7 to withdraw interim accelerated approval of 17-alpha hydroxyprogesterone caproate for preventing recurrent preterm birth because the called for a confirmatory trial, known as the Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial, was not confirmatory. The Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial included subjects enrolled in the United States and Canada to ensure that at least 10% of patients would be from North America; however, this trial took 9 years to complete and did not demonstrate significant treatment effects in the 2 primary outcomes of interest. Delivery before 35 weeks' gestation occurred in 122 of 1130 women (11%) given 17-alpha hydroxyprogesterone caproate compared with 66 of 578 women (11.5%) given placebo (relative risk, 0.95; 95% confidence interval, 0.71-1.26; P=.72). Similarly, the coprimary outcome neonatal composite index occurred in 61 of 1093 women (5.6%) given 17-alpha hydroxyprogesterone caproate compared with 28 of 559 women (5.0%) given placebo (relative risk, 1.12; 95% confidence interval, 0.68-1.61; P=.73). There was also a lack of efficacy for 17-alpha hydroxyprogesterone caproate treatment in the analysis of a variety of secondary outcomes. Like the Maternal-Fetal Medicine Units Network trial, the Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial was also flawed. Importantly, the Maternal-Fetal Medicine Unit Network trial was the sole justification for treating women in the United States with 17-alpha hydroxyprogesterone caproate for nearly 2 decades. Currently, despite more than half a century, 17-alpha hydroxyprogesterone caproate still has not been found to be clearly effective. In this context, how does the advising physician dependent on scientific evidence advise a patient that 17-alpha hydroxyprogesterone caproate is effective when the evidence to support this advice has repeatedly been found to be inadequate? This clinical opinion is a critical appraisal of the 2 randomized trials examining the efficacy of 17-alpha hydroxyprogesterone caproate to prevent recurrent preterm birth and a chronicle of events in the regulatory process of drug approval to help answer this question. With this examination, these events illustrate the complexity of pharmaceutical regulations in the era of accelerated Food and Drug Administration approval and characterize the financial impact and influence in medicine. In this report, we also emphasize the value of observational studies in contemporary practice and identify other examples in medicine where accelerated Food and Drug Administration approval has been withdrawn. Importantly, the themes of the 17-alpha hydroxyprogesterone caproate story are not limited to obstetrics. It can also serve as a microcosm of issues within the US healthcare system, which ultimately contributes to the high cost of healthcare. In our opinion, the answer to the question is clear-the facts speak for themselves-and we believe 17-alpha hydroxyprogesterone caproate should not be endorsed for use to prevent recurrent preterm birth in the United States.