Analysis of umbilical cord tissue as an indicator of in utero exposure to toxic adulterating substances

Implications of xylazine exposure in pregnancy: a narrative review

The rise in pregnancy-related overdose deaths has been driven by the use of high-potency illicitly-manufactured synthetic opioids including fentanyl. Xylazine, a veterinary sedative, is increasingly noted as a common adulterant in the United States illicit opioid supply. Exposure to the xylazine-fentanyl combination has been associated with severe harms including sedation, necrotic wounds, and symptoms of xylazine withdrawal. Due to limited data that directly addresses the risks of xylazine exposure during human pregnancy, we conducted a narrative review to summarize the available evidence about the clinical implications of xylazine exposure in pregnancy drawing from evidence from animal models, the general adult population, and the authors' clinical experiences. Because xylazine exposure presents unique risks to pregnant persons, management of xylazine exposure and related clinical sequelae in pregnant persons warrants nuanced clinical management. Further, additional research is critically needed to develop best practice guidelines related to the management of co-occurring xylazine-opioid exposure during pregnancy including harm reduction strategies to reduce exposure risk during pregnancy.

Prevalence of Psychoactive Substance Use During Pregnancy in Argentine Women: A Pilot Study Testing Maternal Hair

BACKGROUND

The use of psychoactive substances (PSs) during pregnancy is a major public health concern because of their increasing prevalence worldwide. This study examined the understudied issue of gestational PS consumption in a cohort of Argentine delivering mothers.

METHODS

A cross-sectional pilot study involving 51 women receiving delivery care was conducted at the Santa Rosa Hospital in La Pampa, Argentina. Information on maternal sociodemographic characteristics, pregnancy history, and drug use was obtained through standardized interviews. Maternal hair samples were analyzed for alcohol, tobacco, licit, illicit, and prescription substance biomarkers using ultra-high-performance liquid chromatography high-resolution mass spectrometry and gas chromatography mass spectrometry.

RESULTS

During pregnancy, 49.0% of participants reported alcohol consumption, 25.5% reported tobacco use, and 23.5% reported cannabis use. Hair samples from 56.9% of the women were positive for illicit PSs, with the most frequent being cocaine (41.2%) and cannabis (15.7%). Among the women, 47.1% consumed alcohol during pregnancy. Of the 24 women with hair ethyl glucuronide ≥5 pg/mg, 33.3% drank until the end of gestation and 58.3% started a social drinking habit in the second half. The analysis also detected prescription substances (anticonvulsants, antidepressants, methadone, opioids, antihistamines, antiemetics, and analgesics), caffeine (70.6%), lidocaine, and levamisole, some of which were cocaine or opioid adulterants.

CONCLUSIONS

This is the first study to objectively assess the consumption of licit and illicit PSs during pregnancy in Argentina. In contrast to most nearby countries, cocaine was the most detected illicit PS in this cohort of Argentine delivering women. This finding highlights the importance of regular monitoring of local trends in PS use during pregnancy.

Biological Testing and Interpretation of Laboratory Results Associated with Detecting Newborns with Substance Exposure

BACKGROUND

Substance use during pregnancy is common, as is biological testing that is intended to help identify prenatal exposures. However, there is no standardized requirement for biological testing with either maternal or newborn specimens, nor is there standardization related to when testing occurs, how frequently testing occurs, what specimen(s) to test, what substances to test for, or how to perform testing.

CONTENT

We review common specimen types tested to detect maternal and newborn substance exposure with a focus on urine, meconium, and umbilical cord tissue. We also review common analytical methods used to perform testing, including immunoassay, and mass spectrometry platforms. Considerations regarding the utilization of testing relative to the purpose of testing, the drug analyte(s) of interest, the specific testing employed, and the interpretation of results are emphasized to help guide decisions about clinical utilization of testing. We also highlight specific examples of unexpected results that can be used to guide interpretation and appropriate next steps.

SUMMARY

There are strengths and limitations associated with all approaches to detecting substance exposure in pregnant persons as well as biological testing to evaluate a newborn with possible substance exposure. Standardization is needed to better inform decisions surrounding evaluation of substance exposures in pregnant people and newborns. If biological sampling is pursued, testing options and results must be reviewed in clinical context, acknowledging that false-positive and -negative results can and do occur.

Umbilical Cord Tissue: From Antemortem Monitoring to Postmortem Possibilities

ABSTRACT

Umbilical cord tissue (UCT) traditionally has been used as an antemortem matrix for identifying and monitoring fetal exposure to drugs suspected to have been used during pregnancy. The specimen offers several advantages as a testable tissue, including accessibility and ease of collection, ample sample volume, a long window of detection, and ability to detect for a wide range of drugs. Despite these advantages, little to no research exists on the use of UCT as a postmortem forensic toxicology specimen. This article aims to provide insights into UCT toxicological testing and infer potential applications for postmortem use, such as investigations into stillbirths and infant abandonment. Umbilical cord tissue offers several benefits as a postmortem toxicological specimen. Importantly, it can be collected with or without an autopsy being performed and may help explain factors that contribute to the underdevelopment and death of the neonate. With the limited sample volumes present in infant investigations, toxicological analysis of UCT could become a valuable tool for neonatal medicolegal death investigations.

Xylazine Use in Pregnancy: The Effects of the Fentanyl Adulterant Xylazine on Pregnant Patients and the Developing Fetus

Objective

A literature review was completed to outline the effects of xylazine on the pregnant patient while raising awareness of the increasing prevalence of opioid use disorder in pregnancy and the increase in adulterants in non-prescribed controlled substances.

Data Sources

PubMed and Google Scholar were searched using the key words "xylazine, adulterant," "xylazine, humans," "xylazine, pregnancy," and "xylazine, placenta" to identify the studies evaluating xylazine's effects on humans and the pregnant patient.

Study Selection

Studies were included if they provided information on symptoms of xylazine exposure, the prevalence of xylazine in pregnant humans and the hemodynamic effects of xylazine on both human and animal pregnant populations. Animal studies were included given the limited data on xylazine in pregnant humans. Four studies were utilized for background data and five studies were included in the final review of the effects of xylazine on pregnancy.

Results

Studies involving humans show that xylazine toxicity can cause respiratory depression, bradycardia, and central nervous system depression. There is evidence of xylazine in human umbilical cord tissue, showing that the fetus is exposed to xylazine. Animal studies show decreased uterine blood flow, increased uterine vascular resistance, and decreased fetal growth in response to xylazine.

Conclusions

Due to the limited studies on the effects of xylazine on pregnant populations, providers rely on animal studies for knowledge on xylazine's effects throughout pregnancy. Animal studies suggest an increased risk of adverse effects during pregnancy in response to xylazine. Future studies should focus on the pregnancy outcomes in patients exposed to xylazine to create more robust recommendations for treatment and pregnancy surveillance.