Excerpts From the World Medical Literature: Obstetrics.

Abstract

Summary: This was a cross-sectional study among pregnant women admitted for delivery at two urban hospitals in a state with legalized marijuana use. Singleton, viable pregnancies at 24 weeks gestation or more were eligible for the study. The principal goal of the study was to compare subjective reporting of marijuana use with quantitative biological samples from the umbilical cord for the most stable marijuana metabolite, 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). A secondary objective was to correlate the reported frequency of use in the month before delivery with the amount of drug detected in the umbilical cord. Patients were asked to complete an anonymous survey designed by the authors of the study, addressing the frequency and recency of marijuana use in pregnancy. Study identification numbers linked the patients’ survey to their self-report of past or current prenatal marijuana use to a health care provider during the admission history and physical examination. Umbilical cord segments were collected at delivery and tested for the metabolite by liquid chromatography–tandem mass spectrometry only as a batched analysis at the end of study enrolment, in order not to link cord test results to individual patients. The study participants were not informed of the biological testing component of the umbilical cord. The authors note that waiver of consent was granted by the institutional review board for collection of the biological sample; the study could not practicably occur without this waiver, and samples are routinely collected for cord gas analysis and subsequently discarded, thereby ensuring no to minimal risk to the patients. The limit of detection in the cord assay was 100pg/g, and the limit of quantification was 200pg/g. Data analyses were based on 116 patients with both survey and cord data. Gestational ages at delivery were categorized as preterm, less than 37 weeks, and term; term gestational ages were categorized into three groups. More women admitted to past-month use on their self-reported survey compared with when asked by the health care provider (6% vs. 2.6%, respectively). Among cord assays, 22.4% had THC-COOH values above the detection limit (research test threshold), and 10.3% were above the limit of quantification (clinical test threshold). The studyfound poor agreement between self-reported measures of marijuana consumption and objective samples. Many women who reported no consumption in the past 30days actually had positive cord samples for the drug's metabolite.