Abstract Introduction In the past decade, hepatitis C virus (HCV) infections among pregnant women increased dramatically in the United States, rising in parallel with the opioid crisis and increasing the number of children at risk for HCV. People with HCV infection that remains untreated are also at increased risk of cirrhosis, liver cancer, and death. Objective To describe timing of HCV testing during pregnancy and postpartum HCV treatment among women with opioid use disorder (OUD). Methods This analysis draws from the MATernaL and Infant clinical NetworK (MAT‐LINK) surveillance system's cohort of women with OUD during pregnancy, which is collected from electronic health records of seven healthcare systems. Women were included if they had OUD during pregnancy and a known pregnancy outcome during January 1, 2014–August 31, 2021. Antenatal HCV testing was examined by characteristics of pregnant women (including age, race, ethnicity, insurance, urbanicity, parity, and medication for OUD) using multinomial regression. Hepatitis C diagnosis (positive antibody or nucleic acid test or diagnostic code) and postpartum treatment were also examined. Results Among the 5533 pregnancies in this cohort, 1506 (27.2%) had no testing or diagnostic code for hepatitis C including 1296 who received prenatal care. Among 910 pregnancies with no prenatal care, 700 (76.9%) had HCV testing or diagnostic codes. Among pregnancies with HCV testing or diagnostic codes, 55.8% had a hepatitis C diagnosis. Women were more likely to have HCV testing if they were White or Hispanic, had government‐funded insurance, or received medication for OUD during the pregnancy. From five clinical sites with prescription information available, 9.7% (n = 81/836) of those with a detectable viral load had a direct‐acting antiviral prescription in the first year postpartum. Conclusion Women with OUD during pregnancy have a high burden of hepatitis C. Despite national recommendations, gaps remain in HCV testing during pregnancy and HCV treatment postpartum. HCV testing among women with no prenatal care indicates that testing is occurring outside of traditional prenatal care settings. Receiving medication for OUD was associated with being tested for HCV during pregnancy. Improved HCV testing, treatment, and management for pregnant women with OUD represent opportunities for improving overall health and eliminating HCV infection.

Objective:To examine the likelihood of experiencing an overdose among women receiving any buprenorphine (with or without naloxone) compared to women receiving methadone during pregnancy. Methods:Data from the MATernaL and Infant clinical NetworK (MAT-LINK), a longitudinal surveillance system of pregnant woman-child dyads using electronic health records (EHRs), were analyzed. Women from geographically diverse US clinical sites who had a diagnosis of opioid use disorder (OUD) during pregnancy, were prescribed medication for opioid use disorder (MOUD), and had a known birth outcome occurring between January 1, 2014 and August 31, 2021 were included. The Andersen-Gill Cox regression model for recurrent events with robust standard errors was used to model the effect of MOUD type by trimester on time to overdose or date of pregnancy outcome and calculate adjusted hazard ratios (aHRs). Results:Among the 3682 pregnancies included in this analysis, 46 (1.2%) had at least one EHR-documented overdose. None of the overdoses were fatal. In adjusted models, no differences in overdose were observed between pregnancies in which buprenorphine was prescribed or administered compared to pregnancies in which methadone was prescribed or administered (any drug overdose: aHR, 0.62; 95% CI, 0.31-1.23; opioid-involved overdose: aHR, 0.49; 95% CI, 0.18-1.30). In a trimester-specific sub-analysis of pregnancies with at least two MOUD prescriptions or administrations, taking buprenorphine in the third trimester resulted in a decreased likelihood of any drug overdose (aHR, 0.43; 95% CI, 0.20-0.93) and opioid-involved overdose (aHR, 0.32; 95% CI, 0.11-0.92) compared with methadone. Conclusion:It is important that women with OUD are initiated on the medication that works best for them as early as possible during pregnancy and that reinforcement of the importance of MOUD occurs throughout pregnancy, paying special attention to disruptions in treatment during the third trimester that might increase risk for overdose.

Introduction The importance of prenatal determination of chorionicity for the management of twin pregnancies is well recognized. However, research on the contribution of prenatal evaluation of zygosity to the management of twins is limited. We assessed the utility of adding SNP-based cell-free DNA (cfDNA) zygosity testing to ultrasound chorionicity assessment for the clinical management of twin pregnancies.Methods Prospective observational study involving 13 United States practices with proficiency in prenatal ultrasound. Patients diagnosed by ultrasound with twins in the first trimester were assessed with cfDNA screening for zygosity. Ultrasound assessment of chorionicity was performed prior to cfDNA results. Placental pathology was used as the gold standard for chorionicity assessment. Gestational age at delivery and standardized birthweights were compared, based on chorionicity and zygosity.Results 110 twin pregnancies were included. Among 79 dichorionic (DC) cases confirmed by placental pathology, one (1.3%) was misclassified as monochorionic (MC) by ultrasound, but was dizygous (DZ) by cfDNA, consistent with DC. Of 31 monozygotic (MZ) twins by cfDNA, confirmed as MC by pathology, ultrasound misclassified one (3.6%) as DC. Median gestational age at delivery was earlier for MZ twin pregnancies (35.0 weeks) compared to DZ (36.9 weeks, p = 0.02). After adjusting for fetal sex and gestational age at birth, MZDC twins had significantly lower birthweights (p = 0.006) and birthweight percentiles (p = 0.004) than DZDC twins.Conclusions Based on postpartum placental pathology as the reference standard for determining MC versus DC, cfDNA zygosity testing appears to aid in the prenatal assignment of chorionicity. Larger studies are needed to confirm the value of zygosity testing in the management of twin pregnancies.

OBJECTIVES:Opioid use disorder (OUD) and overdose among pregnant and postpartum women pose severe risks to maternal and infant health. Naloxone, a life-saving opioid antagonist, effectively reverses opioid overdoses but remains underutilized in this population. We examined naloxone prescription or receipt and administration during overdose events among perinatal women with OUD from the MATernaL and Infant Clinical NetworK (MAT-LINK). METHODS:We analyzed data collected through 7 MAT-LINK clinical sites from pregnant women with OUD and known pregnancy outcomes between January 1, 2014 and August 31, 2021. Outcomes included naloxone prescriptions and naloxone administration during overdose events during pregnancy or within 12 months postpartum (perinatal period). Weighted prevalence estimates and confidence intervals were calculated by demographic characteristics, substances involved in overdoses, and receipt of medications for opioid use disorder (MOUD). RESULTS:Only 3.1% of women received a naloxone prescription during the perinatal period; the percentage of women receiving naloxone from the clinic without a prescription was unknown and not systematically captured in the data. Women experiencing overdose events most commonly were non-Hispanic, white, had public health insurance, and lived in urban areas, reflecting the demographic composition of the MAT-LINK cohort, with high co-occurrence of tobacco/nicotine (80.5%) and stimulant use disorders (59.2%). Among women who experienced an opioid-involved overdose event, 23.4% were not administered naloxone. No significant demographic differences were observed by naloxone administration. CONCLUSIONS:These findings highlight the need for further investigation into barriers and facilitators to naloxone clinical documentation, access, and use during the perinatal period.

OBJECTIVES:A recent case series suggested a possible syndrome associated with prenatal fentanyl exposure. We described, among a cohort of maternal-infant dyads affected by opioid use disorder (OUD), the prevalence of these observed infant features. METHODS:We used data from MAT-LINK, a surveillance system compiling electronic health record (EHR) information from 7 US clinical sites on pregnancies affected by OUD between 2014 and 2021. We described the prevalence of EHR-documented prenatal fentanyl exposure and infant features of interest (cleft palate, corpus callosum abnormality, foot positioning deformities, genital anomalies, microcephaly, micrognathia, toe syndactyly). RESULTS:Among 5053 maternal-infant dyads affected by OUD, 667 (13.5%; 95% CI: 13.0%-14.0%) had documented prenatal fentanyl exposure, including an over 20-fold increase from 2014 to 2021. Health insurance, prenatal care timing, and nonopioid substance exposures differed between dyads with and without documented prenatal fentanyl exposure. At least one feature of interest was documented for 406 (8.0%) infants, and at least 2 were documented for 0.7%. Among infants with at least one of these features, 18.9% (95% CI: 17.1%-20.8%) had documented prenatal fentanyl exposure, compared with 13.0% (95% CI: 12.5%-13.6%) of infants without any of these features. CONCLUSIONS:In this perinatal OUD cohort, prenatal fentanyl exposure was more commonly documented among infants with at least one compared with none of these infant features. However, features were rare and contextual factors differed among dyads by prenatal fentanyl exposure status. Further analyses examining these infant features, while considering multiple exposures, are needed before substantiating a fetal fentanyl syndrome.

OBJECTIVE:Maternal morbidity and mortality (MMM) rates from drug overdoses have increased, especially among pregnant and postpartum women aged 35-44. However, there is limited understanding of how current toxicology testing practices are implemented in hospital settings and how well they support, or undermine, linkage to care. The goal of the study is to understand variations in toxicology testing use among pregnant and postpartum women, explore hospital- and individual-level differences, and assess outcomes. METHODS:Using the Socio-cultural Framework for the Study of Health Service Disparities (SCF-HSD) we will perform a mixed-methods study to understand testing policies and practices in NY State. Aim 1 will employ multilevel statistical models using New York State Medicaid claims data (2021-2024) to identify predictors of perinatal toxicology testing and characterize hospital-level variation across hospitals. Aim 2 will involve one-on-one interviews with hospital administrators and clinical staff to document and analyze testing policies and practices, capturing diverse perspectives on testing rationales, attitudes, and adherence. Aim 3 will integrate quantitative and qualitative evidence through a mixed-methods design, incorporating perspectives of individuals with lived experience, via focus group sessions to inform and refine hospital policy recommendations. DISCUSSION:Our findings will inform how to improve disparities in toxicology testing for pregnant and postpartum women. Addressing these challenges requires shifting emphasis toward standardized, evidence-based toxicology testing protocols, strengthening pathways to supportive services, and advancing policy reforms that reduce stigma and inequities in care.

Prenatal diagnosis of chorionicity is critical for the management of twin pregnancies. Although ultrasound has been recommended for this, it has not been thoroughly validated. SNP-based cell-free DNA (cfDNA) can determine zygosity from 9 weeks’ gestation. Dizygotic cfDNA infers dichorionicity (DC). Monozygotic (MZ) cfDNA results may require managing the pregnancy as monochorionic (MC), regardless of chorionicity. The purpose of this study was to assess the accuracy of the diagnosis of chorionicity by ultrasound (C-US) prior to knowledge of cfDNA results. Prospective observational registry multi-institutional study (13 sites in the USA). Inclusion criteria were an ongoing twin pregnancy (< 20 weeks’ gestation) with C-US prior to cfDNA. Exclusion criteria were higher order multiples, contraindication for cfDNA, and twin to twin transfusion syndrome prior to enrollment. C-US, cfDNA results, perinatal outcome and placental pathology reports were collected. A total of 137 twin pregnancies were enrolled in the study. After exclusions for undetermined zygosity on cfDNA (1), missing placental pathology (15), incomplete follow-up (11), and unreported chorionicity on ultrasound (4), 106 pregnancies remained. Median gestation at C-US was 11 weeks. Two of 28 (7.1%) pregnancies reported to be MC on pathology were DC on C-US. All were monozygotic on cfDNA. One in 78 pregnancies (1.3%) reported to be DC on pathology was MC on C-US and was dizygotic on cfDNA. Overall, chorionicity was misdiagnosed by C-US in 2.8% (3/106) of twin pregnancies. Of the MZ-cfDNA twins (41.5%, 44/106), 36% were DC and 64% were MC on pathology. All DZ cfDNA twins (62/106, 58.5%) were DC on pathology. Surgical pathology confirmed the cfDNA zygosity diagnosis in all cases. Ultrasound assessment of chorionicity may be inaccurate in approximately 3% of twins. False negative MC diagnosis may preclude timely management of typical MC complications. False positive MC diagnosis may result in unnecessary surveillance or interventions. cfDNA screening for zygosity is essential in the management of twin pregnancies.

To evaluate outcomes in twin pregnancies stratified by zygosity based on SNP-based cell-free DNA screening (cfDNA). Prospective study of twin pregnancies undergoing SNP-based cfDNA following prenatal ultrasound (< 20 weeks’ gestation) at 13 US sites (Oct 2021-March 2023). Pregnancies with twin-to-twin transfusion syndrome (TTTS) prior to enrollment or a contraindication to cfDNA screening were excluded. cfDNA results, ultrasound findings, placental pathology, and maternal and newborn outcomes were collected. Dizygotic twins (DZ) on cfDNA were classified as dichorionic (DC). Monozygotic (MZ) twins on cfDNA were classified as monochorionic (MC) or DC based on placental pathology. Odds ratios (95% confidence intervals) were calculated to compare the pregnancy outcomes for MZ MC and MZ DC twins with those of DZ twins. 137 patients enrolled in the study. After exclusions for undetermined cfDNA (1), incomplete follow-up (11), and MZ twins with no placental pathology (2), 123 patients remained in the cohort: 76 DZ, 31 MZ MC, and 16 MZ DC. Placental pathology was available for 63/76 (82.9%) DZ twins and was DC in all. Median gestation at cfDNA was 12+5 weeks. Pregnancy outcomes by zygosity and chorionicity are shown in Table 1. TTTS occurred in 3.2%, selective intrauterine growth restriction (SIUGR) in 22.6%, and twin-anemia-polycythemia sequence (TAPS) in 9.7% of MC twins. MZ MC twins had the highest incidence of pregnancy complications including preterm birth and NICU admission. The incidence of small-for-gestational age (SGA) (birth weight < 10th percentile) was higher in the MZ DC group compared to the DZ group (OR=2.51; 95% CI 1.08,5.87). SNP-based cfDNA in twin pregnancies can be used to determine the rate of complications by zygosity. This may help establish the actual rates of specific complications of MC twins, such as TTTS, SIUGR, and TAPS. The finding of a high incidence of SGA in MZ DC vs DZ DC twins may have important research and clinical implications, particularly on the frequency of growth surveillance.

ObjectivesTo describe patterns of medication for opioid use disorder (MOUD) during pregnancies in the opioid use disorder (OUD) cohort of MAT-LINK, a sentinel surveillance network of pregnancies at US clinical sites.MethodsSeven clinical sites providing care for pregnant people with OUD collected electronic health record data. Pregnancies were included in this analysis if (1) the pregnancy outcome occurred between January 2014 and August 2021, (2) the person had OUD, and (3) there was any electronic health record-documented MOUD during pregnancy. Analyses describing MOUD type, demographic characteristics, and timing during pregnancy were performed.ResultsAmong 3911 pregnancies with any documented MOUD, more than 90% of pregnancies with methadone were to publicly insured people, which was greater than percentages for pregnancies with other MOUD. Buprenorphine with naloxone and naltrexone were two MOUD types that were increasingly common among pregnant people in recent years. In most pregnancies, prenatal care and MOUD were first documented in the same trimester. During the first, second, and third trimesters, there were 37%, 61%, and 91% of pregnancies with MOUD, respectively. Approximately 87% (n = 3412) had only 1 documented MOUD type, versus 2 or 3 types. However, discontinuity in MOUD across trimesters was still observed.ConclusionsIn MAT-LINK's OUD cohort, the overall frequency of MOUD improved over the course of pregnancy. Contextual factors, such as insurance status and year of pregnancy outcome, might influence MOUD type. Prenatal care and MOUD might be facilitators for one another; however, there are still opportunities to improve early linkage and continuous access to both prenatal care and MOUD during pregnancy.

Organ-level models are used to describe how cellular and tissue-level contractions coalesce into clinically observable uterine contractions. More importantly, these models provide a framework for evaluating the many different contraction patterns observed in laboring patients, ideally offering insight into the pitfalls of currently available recording modalities and suggesting new directions for improving recording and interpretation of uterine contractions. Early models proposed wave-like propagation of bioelectrical activity as the sole mechanism for recruiting the myometrium to participate in the contraction and increase contraction strength. However, as these models were tested, the results consistently revealed that sequentially propagating waves do not travel long distances and do not encompass the gravid uterus. To resolve this discrepancy, a model using 2 mechanisms, or a "dual model," for organ-level signaling has been proposed. In the dual model, the myometrium is recruited by action potentials that propagate wave-like as far as 10 cm. At longer distances, the myometrium is recruited by a mechanotransduction mechanism that is triggered by rising intrauterine pressure. In this review, we present the influential models of uterine function, highlighting their main features and inconsistencies, and detail the role of intrauterine pressure in signaling and cervical dilation. Clinical correlations demonstrate the application of organ-level models. The potential to improve the recording and clinical interpretation of uterine contractions when evaluating labor is discussed, with emphasis on uterine electromyography. Finally, 7 questions are posed to help guide future investigations on organ-level signaling mechanisms.

BACKGROUND: Beta-lactam antibiotics (eg, penicillins, cephalosporins, and carbapenems) are preferred for group B streptococcus prophylaxis, intra-amniotic infection, and cesarean surgical site infection prophylaxis. Non-beta-lactam alternatives are associated with inferior efficacy and contribute to higher rates of surgical site infection and longer lengths of stay. Most patients who report a penicillin allergy can tolerate penicillins without any adverse reaction. There are low rates of cross -reac-tivity between penicillins and other beta-lactams, including cephalosporins and carbapenems. Efforts to evaluate penicillin allergy and promote the use of beta-lactams are needed.OBJECTIVE: This study aimed to evaluate whether an antimicrobial stewardship intervention improved the use of first-line antibiotics for peri-partum indications in patients with a reported penicillin allergy, following updates to institutional guidelines.STUDY DESIGN: This was a retrospective study of adult patients presenting for vaginal or cesarean delivery at 2 hospitals within a healthcare system. Patients received at least 1 dose of antibiotics for a peripartum indication between May 1, 2018, and October 31, 2018 (preintervention group) and May 1, 2020, to October 31, 2020 (postintervention group). The stewardship intervention bundle, which was implemented between March 2019 and April 2020, included updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of obstetrical prophylaxis and treatment order sets, promotion of allergy referral services, and establishment of a physician champion. The primary outcome was the composite rates of patients with reported penicillin allergy who received a preferred antibiotic for a peripartum indication. The secondary measures included maternal and neonatal outcomes.RESULTS: A total of 192 patients with a history of documented penicillin allergy were evaluated (96 patients in the preintervention group and 96 patients in the postintervention group). Hives were the most commonly reported index symptom in both groups (40/96 [41.7%] vs 39/96 [40.6%]; P=.883). After stewardship interventions, there was a significant increase in the rate of preferred antibiotic use (33/96 [34.3%] vs 81/96 [84.3%]; P<.001). The effect was the greatest in patients with nonsevere allergy (14/76 [18.4%] vs 68/82 [82.9%]; P<.001). There was no differ-ence in the rates of postpartum endometritis, 30-day readmission, 90-day surgical site infection, or neonatal early-onset sepsis between the pre -and postintervention groups. Of note, 1 patient in the postintervention group experienced itching, and another patient developed a rash, both of which resolved with medical management.CONCLUSION: A comprehensive antibiotic stewardship intervention was associated with a 50% increase in the use of preferred antibiotics for peripartum indications in patients with penicillin allergy. Allergic reactions with first-line beta-lactams were minimal and manageable.

Multichannel uterine electromyography (uEMG) during pregnancy is traditionally performed with electrocardiography (ECG) sensors. Similar signals are often observed in two or more channels, suggesting the ECG sensors report activities originating from the same location on the uterus. To improve signal source localization, we designed a directional sensor or “Area Sensor”. Here we compare Area Sensors with ECG sensors for source localization. Subjects were ≥ 38 wks experiencing regular contractions. 6 Area Sensors (n = 8) or 6 to 7 ECG sensors (n = 7) were used to record multichannel uEMG for 60 min. For each sensor type, the similarity of signals observed in pairs of channels during contractions was assessed by quantifying channel crosstalk. Since crosstalk depends on the separation between sensors, analyses were performed within distance groups: A 9–12 cm; B 13–16 cm; C 17–20 cm; D 21–24 cm; E ≥ 25 cm. For ECG sensors, crosstalk was 67.9 ± 14.4

This case presents a novel occurrence of a de novo BRCA1 gene deletion in a fetus with a cystic hygroma. Chorionic villus sampling (CVS) was performed for chromosome G-banding analysis, demonstrating a normal karyotype: 46, XX. Chromosome microarray analysis performed as a reflex test revealed an 80 kb deletion on 17q21.31, encompassing the BRCA1 gene. Follow-up FISH analysis performed on parental blood samples yielded negative results, confirming that the deletion was de novo in the fetus. Subsequent anatomic ultrasound evaluation showed no identifiable structural defects, and it was concluded that the microdeletion was unlikely to be the cause of the cystic hygroma. Regardless, it will be imperative that the patient’s daughter be appropriately counseled regarding the implications of carrying a BRCA1 deletion and the need for heightened surveillance in adulthood. As BRCA1 genetic testing is traditionally performed on adult patients with informed consent, this case report highlights the need for ongoing conversations and research in the management of incidental fetal diagnosis discovered during routine prenatal testing, as well as the care and counseling of these patients and their families.

Background: Women with short cervix and a prior history of spontaneous preterm birth (PTB) and who are currently pregnant with a singleton gestation are considered high-risk for recurrent PTB. Serial cervical length screening can be used to identify high-risk women; those who are positively identified can be treated with either cerclage or vaginal progesterone.Objective: To evaluate the cost and effectiveness of serial cervical length screening strategies versus no screening in preventing preterm birth among women in the United States with a singleton gestation and history of preterm birth. Study Design: We developed a decision analytic model comparing serial cervical length screening plus either one of two treatment for confirmed short cervix (1. vaginal progesterone, 2. cerclage plus 17-alpha-hydroxy-progesterone caproate) compared with no screening. Costs included procedures, medications, and direct healthcare costs of delivery plus material and neonatal costs for one-year post delivery. Effectiveness was defined as the probability of successfully preventing one preterm birth at a threshold of 37 and 35 weeks. The main outcome was the difference in cost and effectiveness between the two screening methods versus no screening.Results: The cost of screening plus vaginal progesterone ($54,686) was less than the cerclage ($59,032) and no screening ($58,895) arms. At 37 weeks, the incremental effectiveness of the cerclage versus no screening arms (0.0257) was higher than the progesterone versus no screening arms (0.0063). At week 35, compared with the no screening, vaginal progesterone was less effective (-0.0036) while screening plus cerclage was slightly more effective (0.0066). Our model is most sensitive to variation in delivery and hydroxyprogesterone costs. Probabilistic sensitivity analysis indicates that VP is less costly than no screening 79.4% of the time, and cerclage is less costly than no screening 30.5% of the time.Conclusions: While serial screening with vaginal progesterone was a more cost-saving strategy, the cerclage strategy prevented more preterm births at a marginal additional cost compared to no screening.

Problem: Medication for opioid use disorder (MOUD) is recommended for persons with opioid use disorder (OUD) during pregnancy. However, knowledge gaps exist about best practices for management of OUD during pregnancy and these data are needed to guide clinical care. Period Covered: 2014-2021. Description of the System: Established in 2019, the Maternal and Infant Network to Understand Outcomes Associated with Medication for Opioid Use Disorder During Pregnancy (MAT-LINK) is a surveillance network of seven clinical sites in the United States. Boston Medical Center, Kaiser Permanente Northwest, The Ohio State University, and the University of Utah were the initial clinical sites in 2019. In 2021, three clinical sites were added to the network (the University of New Mexico, the University of Rochester, and the University of South Florida). Persons receiving care at the seven clinical sites are diverse in terms of geography, urbanicity, race and ethnicity, insurance coverage, and type of MOUD received. The goal of MAT-LINK is to capture demographic and clinical information about persons with OUD during pregnancy to better understand the effect of MOUD on outcomes and, ultimately, provide information for clinical care and public health interventions for this population. MAT-LINK maintains strict confidentiality through robust information technology architecture. MAT-LINK surveillance methods, population characteristics, and evaluation findings are described in this inaugural surveillance report. This report is the first to describe the system, presenting detailed information on funding, structure, data elements, and methods as well as findings from a surveillance evaluation. The findings presented in this report are limited to selected demographic characteristics of pregnant persons overall and by MOUD treatment status. Clinical and outcome data are not included because data collection and cleaning have not been completed; initial analyses of clinical and outcome data will begin in 2023. Results: The MAT-LINK surveillance network gathered data on 5,541 reported pregnancies with a known pregnancy outcome during 2014-2021 among persons with OUD from seven clinical sites. The mean maternal age was 29.7 (SD = +/- 5.1) years. By race and ethnicity, 86.3% of pregnant persons were identified as White, 25.4% as Hispanic or Latino, and 5.8% as Black or African American. Among pregnant persons, 81.6% had public insurance, and 84.4% lived in urban areas. Compared with persons not receiving MOUD during pregnancy, those receiving MOUD during pregnancy were more likely to be older and White and to have public insurance. The evaluation of the surveillance system found that the initial four clinical sites were not representative of demographics of the South or Southwest regions of the United States and had low representation from certain racial and ethnic groups compared with the overall U.S. population; however, the addition of three clinical sites in 2021 made the surveillance network more representative. Automated extraction and processing improved the speed of data collection and analysis. The ability to add new clinical sites and variables demonstrated the flexibility of MAT-LINK. Interpretation: MAT-LINK is the first surveillance system to collect comprehensive, longitudinal data on pregnant person-infant dyads with perinatal outcomes associated with MOUD during pregnancy from multiple clinical sites. Analyses of clinical site data demonstrated different sociodemographic characteristics between the MOUD and non-MOUD treatment groups. Public Health Actions: MAT-LINK is a timely and flexible surveillance system with data on approximately 5,500 pregnancies. Ongoing data collection and analyses of these data will provide information to support clinical and public health guidance to improve health outcomes among pregnant persons with OUD and their children.

OBJECTIVE: To characterize clinical management of deliveries resulting in neonatal hypoxic ischemic encephalopathy. DESIGN: Retrospective case series SETTING: Three academic referral medical centers in the United States POPULATION: All neonates ≥35 weeks’ gestation with HIE based on cord blood pH<7.0, base deficit of ≥12.0mmol/L, along with relevant radiological, laboratory, and clinical findings. METHODS: Clinical management was characterized based on whether (i)delivery occurred within 120 minutes of presentation, (ii)delivery occurred due to a sentinel event such as cord prolapse or uterine rupture, and (iii)the fetal heart rate tracing(FHR) demonstrated variability, accelerations, or both upon presentation and in the half hour before delivery. MAIN OUTCOME MEASURES: Relationship of mode of delivery to FHR tracing characteristics at delivery. Obstetric outcomes, labour course and management were analysed. RESULTS: Of 144,904 deliveries, 102 maternal-newborn dyads met criteria. Of these, 19 delivered within 120 of minutes of presentation and four further women experienced a sentinel event. Of the remaining 79, 66(84%) had a FHR tracing on presentation that demonstrated variability, accelerations or both. Of these 66 cases, 27 had a fetal heart tracing that demonstrated variability, accelerations or both in the 30 minutes preceding delivery. CONCLUSION: Approximately two-thirds of cases of HIE occurred in cases where the FHR tracing initially demonstrated variability, accelerations, or both, without a sentinel event and without a condition requiring delivery within 120 minutes of presentation. Of these >40% had variability, accelerations, or both in the half hour before delivery. This suggests additional insights are required to prevent some cases of HIE.

The global contractions of "true" labor result from synchronization of multiple regional contractions each constituting an area of myometrium ∼10cm. To assess whether there is global synchronization with uterine electromyography (uEMG) requires sensors with directional characteristics sufficient to resolve these individual regions. We previously showed that open area sensors localize signal origin better than traditional pads (Fig 1) in normal/overweight patients. The objective was to determine if area sensors provide the signal independence needed to measure individual regional activity in obese patients. Secondary analysis of a prospective cohort study of singletons >30wks GA presenting for evaluation of self-reported, regular contractions. 60 minute uEMG recordings were obtained. 6 abdominal sensors were placed at least 8cm (center-center) and distances between sensor pairs was recorded. Three groups of 4 patients each were created based on body mass index (BMI) as follows: 20-29.9, 30-34.9, and ≥35kg/m2. Primary outcome was presence of signal independence. Sensor dependence was calculated using root mean squared (RMS) of the voltage difference (dV) between sensor pairs. If dV was ≥50% of the RMS of the larger channel, the sensors were recording different signals (Fig 2). Pairs of sensors recording the same signal were defined as dependent and those recording different signals were defined as independent. At distances < 14cm dependence can be due to chance location; >14cm indicates poor directional characteristics. 16 contractions from 4 patients were analyzed for a total of 144dV per group. The number of independent signals (n=131, 134, 125) and dependent signals (n=13, 10, 19) were similar in the 20-29.9, 30-34.9, and ≥35 BMI groups respectively. Of the dependent signals, each BMI group showed 2 (1.4%) signals at a sensor distance of >14cm. The signal independence of directional uEMG sensors is not affected by obesity. Obesity is increasingly common in OB patients; technology aimed at assessing "true" from false labor will need to be available to all patients.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Opioid use disorder (OUD) is a known risk factor for pregnancy-related maternal deaths and greatly contributes to other obstetrical and neonatal complications. Physicians are urged to obtain a US Drug Enforcement Administration (DEA) waiver (x-waiver) to reduce use associated risks through prescribing buprenorphine. This study aims to observe the number and geographic distribution of x-waivered physicians in New York (NY), with a focus on OB/GYN providers. Waivered physicians in NY were identified using the Substance Abuse and Mental Health Services Administration (SAMHSA) Buprenorphine Practitioner Locator from June 2021. Provider specialty was then determined through linking the SAMHSA locator and external datasets (ie. Centers for Medicare and Medicaid Services Physician Compare and the NY State Department of Health Individual Provider Network Data). Geographic distribution of waivered physicians was mapped on a county level and descriptive statistics were performed. In NY, 2965 x-waivered physicians were identified practicing in 59 of the 62 counties with 2.6% (n=76) of the practitioners working in 2 or more counties. The figure shows the distribution of waivered providers relative to opioid burden per county (Figure). Of the total providers, 1.5% (n=46) identified as OB/GYN (includes MFM) with at least one OB/GYN practicing in 20 counties. None of these OB/GYN are located in a county where need exceeds 90% of treatment capacity. Relative to county neonatal abstinence syndrome (NAS) rates, most counties (n=14/23; 60%) with above median NAS rates have no waivered OB/GYN whereas 52% of counties with below median NAS rates have at least 1 waivered OB/GYN. In nearly all counties with above median NAS rates (n=22/23; 96%), there is sufficient capacity to treat. OB/GYNs constitute only a small percentage of x-waivered providers in NY and are typically located in counties where there is sufficient capacity to treat OUD and with below median NAS rates. Future efforts should target increasing the number of waivered OB/GYNs in counties with the greatest need.