Measures of Maternal Metabolic Health as Predictors of Severely Low Milk Production.

Background: A comprehensive approach to breastfeeding support requires elucidation of how metabolic health influences milk production. Objective: We compared metabolic health indicators in women with severely low milk output versus those with moderate/normal milk output using a case-control study design, with nested and external control groups. Design: Cases and nested controls were derived from women screened for a low milk supply trial, with cases defined as severely low milk output (<300 mL/24 hours), and nested controls defined as moderate/normal milk output (>300 mL/24 hours). In addition, we included an external control group of exclusively breastfeeding women. All were enrolled at 2-10 weeks postdelivery of a healthy term infant. Milk output and breast emptying frequency were recorded through test-weigh. Metabolic health variables included all components of the metabolic syndrome, homeostatic model assessment of insulin resistance (HOMA-IR), and diagnosis of gestational diabetes mellitus (GDM). Results: Maximum milk output, mL/24 hours, ranged as follows: 30-281 in cases (n = 18), 372-801 in nested controls (n = 12), and 661-915 in external controls (n = 12). Mean breast emptying frequency in cases was not significantly different from nested or external controls. All metabolic syndrome components and HOMA-IR were significantly worse in cases as compared with both nested and external control groups (p < 0.05). There was no significant difference between the nested and external control groups for these variables. GDM prevalence was 39%, 0%, and 8%, across cases, nested control, and external control groups, respectively (chi-square p-value = 0.02). Conclusion: Results from this small case-control study identify class 2+ obesity and poor metabolic health as strong risk factors for severely low milk production. These findings should be further validated in larger prospective cohort studies designed to identify individuals at risk for metabolically driven low milk supply. In addition, clinical and qualitative research studies aimed at improving patient-centered approaches to the management of persistent low milk supply are needed.

Physiologically-Based Pharmacokinetic Modeling to Investigate the Effect of Maturation on Buprenorphine Pharmacokinetics in Newborns with Neonatal Opioid Withdrawal Syndrome.

Neonatal opioid withdrawal syndrome (NOWS) is a major public health concern whose incidence has paralleled the opioid epidemic in the United States. Sublingual buprenorphine is an emerging treatment for NOWS, but given concerns about long-term adverse effects of perinatal opioid exposure, precision dosing of buprenorphine is needed. Buprenorphine pharmacokinetics (PK) in newborns, however, is highly variable. To evaluate underlying sources of PK variability, a neonatal physiologically-based pharmacokinetic (PBPK) model of sublingual buprenorphine was developed using Simcyp (version 19.1). The PBPK model included metabolism by cytochrome P450 (CYP) 3A4, CYP2C8, UDP-glucuronosyltransferase (UGT) 1A1, UGT1A3, UGT2B7, and UGT2B17, with additional biliary excretion. Maturation of metabolizing enzymes was incorporated, and default CYP2C8 and UGT2B7 ontogeny profiles were updated according to recent literature. A biliary clearance developmental profile was outlined using clinical data from neonates receiving sublingual buprenorphine as NOWS treatment. Extensive PBPK model validation in adults demonstrated good predictability, with geometric mean (95% confidence interval (CI)) predicted/observed ratios (P/O ratios) of area under the curve from zero to infinity (AUC0-∞ ), peak concentration (Cmax ), and time to reach peak concentration (Tmax ) equaling 1.00 (0.74-1.33), 1.04 (0.84-1.29), and 0.95 (0.72-1.26), respectively. In neonates, the geometric mean (95% CI) P/O ratio of whole blood concentrations was 0.75 (95% CI 0.64-0.87). PBPK modeling and simulation demonstrated that variability in biliary clearance, sublingual absorption, and CYP3A4 abundance are likely important drivers of buprenorphine PK variability in neonates. The PBPK model could be used to guide development of improved buprenorphine starting dose regimens for the treatment of NOWS.

Predictors of the Provision of Mother's Milk Feedings in Newborns Admitted to the Neonatal Intensive Care Unit.

Background: Breast milk reduces morbidity and mortality in infants admitted to neonatal intensive care unit (NICU). Objectives: We determined predictors of procuring mother's own milk (MOM) among NICU-admitted newborn-mother dyads: (1) initiation of any milk expression; (2) initiation of milk expression within 6 hours of birth; (3) MOM as the first enteral feeding; (4) colostrum for oral care within 36 hours of birth if not yet orally fed; and (5) provision of MOM at 21 days of life or discharge, whichever occurred first. Methods: We performed a retrospective chart review of NICU-admitted newborn-mother dyads at an urban medical center from June 1, 2018-May 31, 2019. We excluded infants not directly admitted to the NICU, those never enterally fed, multiple gestations if not the first to be discharged, and infants discharged to a nonbiological caregiver. We used chi-square analysis to examine unadjusted associations between independent variables and MOM outcomes and then used logistic regression to determine the adjusted odds ratio and 95% confidence interval (AOR [95% CI]) for predictors of MOM outcomes. Results: There were 341 mother-infant dyads who met inclusion criteria and 71% of these mothers initiated milk expression. Smoking, multiparity, gestational diabetes, and Hepatitis C lowered the odds for at least one MOM outcome; whereas mothers who delivered at 28-32 weeks versus ≥33 weeks, and infants with birthweight <1,500 g versus 1,500-2,500 g had higher odds for at least one MOM outcome. Conclusion: Maternal/infant dyad characteristics may predict some, but not all NICU breastfeeding outcomes. This suggests that hospital practices may influence these outcomes and can inform future interventions.

First-Day Use of the Newborn Weight Loss Tool to Predict Excess Weight Loss in Breastfeeding Newborns.

Background and Objectives: Exclusive breastfeeding is recommended for most newborns. However, exclusively breastfed newborns sometimes experience excess weight loss (EWL, loss ≥10% of birth weight) while lactation is being established. Our primary objective was to evaluate the sensitivity and specificity of the Newborn Weight Loss Tool (NEWT) in early identification of exclusively breastfed newborns who develop EWL; and secondarily, identify breastfeeding variables associated with an at-risk NEWT trajectory. Materials and Methods: We conducted a secondary analysis of prospective data from mother-infant dyads screened for inclusion in the U.S. site of the WHO Growth Reference Study. We excluded records if: NEWT-specific criteria not met, missing key data, or >60 mL formula consumed. We defined NEWT "test-positive" based on an in-hospital weight at about 24 hours falling within the NEWT trajectory consistent with eventual EWL. We defined cases as true EWL based on weight measured at home on day of life 4 (DoL4). Results: Of 280 original records, 60 were excluded (n = 27, NEWT-specific exclusion; n = 15, missing data; n = 18, >60 mL formula), resulting in 220 paired newborn weights measured in-hospital (17 ± 8 hours), and at DoL4 (84 ± 8 hours). NEWT status correctly identified 6/28 EWL cases (21% sensitivity [95% confidence interval, CI, 8-34%]), and 158/192 noncases (82% specificity [95% CI, 75-89%]). NEWT test-positive status was associated with greater weight loss, lower perceived breastfeeding support, and infant less often showing feeding cues on DoL4 (p < 0.05). Conclusion: Sensitivity in predicting EWL is low when applying NEWT at about 24 hours of life; however, early test-positive status is associated with indicators of breastfeeding difficulties on DoL4.

Impact of Institutional Breastfeeding Support in Very Low-Birth Weight Infants.

Background and Objectives: Feeding of human milk is associated with improved health outcomes in preterm infants. Mothers of preterm infants have difficulty establishing and maintaining an adequate milk supply. Our institution participated in Best Fed Beginnings (BFB), a national breastfeeding quality improvement collaborative, in 2012. Although most practice changes targeted healthy term infants, we hypothesized that mother's milk feeding (MMF) to preterm infants would also improve. Our objective was to compare MMF in very low-birth weight (VLBW) infants at discharge before and after our participation in BFB. Materials and Methods: We completed a retrospective chart review of VLBW infants born between January 2006 and June 2016. The primary outcome measure was the percentage of VLBW infants receiving MMF at hospital discharge. We used Fisher's exact test to determine the difference before and after 2012 and performed the Kruskal-Wallis test to determine changes in median time to pump initiation in mothers of VLBW infants. Multiple logistic regression was used to determine variables associated with the primary outcome. Results: A total of 1,077 VLBW infants were eligible. After launching BFB, MMF at discharge increased in VLBW infants, from 35.2% to 46.0%, p < 0.001. Median time to pump initiation decreased from 11 to 5 hours after 2012, p = 0.0001. Factors significantly associated with receiving MMF at discharge included birth post-BFB; private insurance; non-Black race; shorter length of stay; older maternal age; and mother's milk as first feeding. Conclusions: Hospital culture supportive of breastfeeding impacts not only healthy term infants but also VLBW infants. Earlier initiation of milk expression significantly improves provision of MMF to preterm infants at discharge.

Buprenorphine pharmacotherapy for the management of neonatal abstinence syndrome in methadone-exposed neonates.

We aimed to compare the outcomes of pharmacotherapy with either buprenorphine or methadone in infants treated for neonatal abstinence syndrome (NAS) secondary to intrauterine exposure to methadone. This is a multi-center, retrospective cohort study to assess length of treatment (LOT), hospital length of stay (LOS), and cumulative opioid exposure between infants treated with either methadone or buprenorphine for NAS secondary to in utero exposure to methadone. Infants delivered at a gestational age ≥35 weeks and a maternal history of opioid-use disorder and/or urine drug screen positive for methadone, and postnatal pharmacotherapy for NAS with either buprenorphine or methadone as first-line opioid replacement therapy, were eligible. Median LOT, LOS, and cumulative opioid exposure were compared between buprenorphine- and methadone-treated infants. A total of 156 infants (48 treated with buprenorphine and 108 with methadone) were identified. The median LOT and LOS for buprenorphine-treated infants was 8 and 13 days compared with 15 and 20 days for methadone-treated infants, respectively, P < .001 for both outcomes. Median cumulative opioid dose in morphine equivalents was 0.6 mg/kg for buprenorphine-treated infants vs 1.05 mg/kg for methadone-treated infants, P < .001. No adverse effects were noted among either group. Of infants treated with buprenorphine, 34 (71%) required the addition of adjunctive pharmacotherapy during the NICU stay, compared with 31 (32%) in the methadone-treated group, P = .0008. However, significantly fewer infants treated with buprenorphine required continuation of therapy beyond discharge as compared with those treated with methadone. The difference is most likely a reflection of the protocols used by the sites. In infants that required pharmacotherapy for NAS secondary to intrauterine exposure to methadone, treatment with buprenorphine, compared with methadone therapy, was associated with better outcomes. If confirmed with prospective data, buprenorphine could be considered first-line therapy for the two medication-assisted treatment regimens recommended by the American College of Obstetricians and Gynecologists.

Improving Exclusive Breastfeeding in an Urban Academic Hospital.

BACKGROUND AND OBJECTIVE: Breastfeeding has many well-established health benefits for infants and mothers. There is greater risk reduction in health outcomes with exclusive breastfeeding (EBF). Our urban academic facility has had long-standing low EBF rates, serving a population with breastfeeding disparities. We sought to improve EBF rates through a Learning Collaborative model by participating in the Best Fed Beginnings project. METHODS: Formal improvement science methods were used, including the development of a key driver diagram and plan-do-study-act cycles. Improvement activities followed the Ten Steps to Successful Breastfeeding. RESULTS: We demonstrated significant improvement in the median adherence to 2 process measures, rooming in and skin-to-skin after delivery. Subsequently, the proportion of infants exclusively breastfed at hospital discharge in our facility increased from 37% to 59%. We demonstrated an increase in sustained breastfeeding in a subset of patients at a postpartum follow-up visit. These improvements led to Baby-Friendly designation at our facility. CONCLUSIONS: This quality improvement initiative resulted in a higher number of infants exclusively breastfed in our patient population at "high risk not to breastfeed." Other hospitals can use these described methods and techniques to improve their EBF rates.

Pharmacokinetics of Oral Methadone in the Treatment of Neonatal Abstinence Syndrome: A Pilot Study.

OBJECTIVE: To characterize the population pharmacokinetics of oral methadone in neonates requiring pharmacologic treatment of neonatal abstinence syndrome and to develop a pharmacokinetic (PK) model toward an evidence-based treatment protocol. STUDY DESIGN: Based on a methadone dosing protocol, serum concentrations of methadone and its metabolites were assessed by high performance liquid chromatography-tandem mass spectrometry from dried blood spots. Population PK analysis was performed to determine the volume of distribution and clearance of oral methadone. Methadone plasma concentration-time profiles were simulated from the deduced PK model to optimize the dosing regimen. RESULTS: There was substantial interindividual variability in methadone concentrations. Blood concentrations of methadone were best described by a 1-compartment model with first-order absorption. The population mean estimates (coefficient of variation percentage) for oral clearance and volume of distribution were 8.94 (103%) L/h/70 kg and 177 (133%) L/70 kg, respectively. Optimized dosing strategies were developed based on the simulated PK profiles. We suggest a starting dose of 0.1 mg/kg per dose every 6 hours for most patients requiring pharmacologic treatment of neonatal abstinence syndrome followed by an expedited weaning phase. CONCLUSIONS: The proposed dosing regimen may reduce the cumulative dose of opioid and shorten the length of hospitalization. Future studies should aim to validate the simulated dosing schemes with clinical data and expand our understanding of the between-patient PK variability. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01754324.

Universal maternal drug testing in a high-prevalence region of prescription opiate abuse.

OBJECTIVE: To evaluate the efficacy of a universal maternal drug testing protocol for all mothers in a community hospital setting that experienced a 3-fold increase in neonatal abstinence syndrome (NAS) over the previous 5 years. STUDY DESIGN: We conducted a retrospective cohort study between May 2012 and November 2013 after the implementation of universal maternal urine drug testing. All subjects with positive urine tests were reviewed to identify a history or suspicion of drug use, insufficient prenatal care, placental abruption, sexually transmitted disease, or admission from a justice center, which would have prompted urine testing using our previous risk-based screening guidelines. We also reviewed the records of infants born to mothers with a positive toxicology for opioids to determine whether admission to the special care nursery was required. RESULTS: Out of the 2956 maternal specimens, 159 (5.4%) positive results were recorded. Of these, 96 were positive for opioids, representing 3.2% of all maternity admissions. Nineteen of the 96 (20%) opioid-positive urine tests were recorded in mothers without screening risk factors. Seven of these 19 infants (37%) required admission to the special care nursery for worsening signs of NAS, and 1 of these 7 required pharmacologic treatment. CONCLUSION: Universal maternal drug testing improves the identification of infants at risk for the development of NAS. Traditional screening methods underestimate in utero opioid exposure.

Factors associated with readmission in late-preterm infants: a matched case-control study.

OBJECTIVE: The goal of this study was to evaluate risk factors for readmission among late-preterm (34-36 weeks' gestation) infants in clinical practice. METHODS: This was a retrospective, matched case-control study of late-preterm infants receiving care across 8 regional hospitals in 2009 in the United States. Those readmitted within 28 days of birth were matched to non-readmitted infants at a ratio of 1:3 according to birth hospital, birth month, and gestational age. Step-wise modeling with likelihood ratio tests were used to develop a multivariable logistic regression model. A subgroup analysis of hyperbilirubinemia readmissions was also performed. RESULTS: Of 1861 late-preterm infants delivered during the study period, 67 (3.6%) were readmitted within 28 days of birth. These were matched to 201 control infants, for a final sample of 268 infants. In multivariable regression, each additional day in length of stay was associated with a significantly reduced odds ratio (OR) for readmission (0.57, P = .004); however, for those infants delivered vaginally, there was no significant association between length of stay and readmission (adjusted OR: 1.08, P = .16). A stronger inverse relationship was observed in subgroup analysis for hyperbilirubinemia readmissions, with the adjusted OR associated with increased length of stay 0.40 (P = .002) for infants born by cesarean delivery but 1.14 (P = .27) for those delivered vaginally. CONCLUSIONS: Infants born via cesarean delivery with longer length of hospital stay have a decreased risk for readmission. As hospitals implement protocols to standardize length of stay, mode of delivery may be a useful factor to identify late-preterm infants at higher risk for readmission.

Alpha-2A adrenergic receptor subtype gene expression in the intestines of cocaine-exposed rat embryos.

Cocaine has become a popular illicit drug in our society, and pregnant women are not immune from this epidemic. Recently, there have been several references in the literature describing an association between prenatal cocaine exposure and the subsequent development of necrotizing enterocolitis in the neonate, but the mechanism underlying this relationship remains speculative. Because alpha-2 adrenergic receptors are thought to play a role in the autoregulatory mechanism in the newborn intestine that responds to hypoxia and ischemia, we examined the expression of this receptor in the intestine of embryonic rats exposed to low- and high-dose cocaine in utero. Pregnant Sprague Dawley rats were injected daily with either saline, low-dose cocaine, or high-dose cocaine beginning on embryonic d 5 (E 5) and continuing to E 20. Mothers were killed on E 16, E 17, E 18, E 19, and E 20. Embryos were frozen and stored at -80 degrees C. In situ hybridization was performed on 20- micro m sections with 35S-labeled oligonucleotide probes specific for the alpha-2A adrenergic receptor subtype. Densitometric analysis revealed a significant decrease in the alpha-2A receptor expression in the intestine of both the low-dose and high-dose cocaine-exposed animals compared with controls. This down-regulation was demonstrated by E 17, and continued through the remainder of gestation. These changes may limit the normal adaptation to vasoconstriction, thus exacerbating the already insufficient compensatory mechanisms for responding to ischemic injury, and thus may be one of the important factors predisposing cocaine-exposed infants to necrotizing enterocolitis.