Arch Womens Ment Health DOI 10.1007/s00737-015-0534-z
Prevalence and risk factors for cannabis use in low-income pregnant women in São Paulo, Brazil Janet E. Shu 1,2 & Hsiang Huang 1,2,3 & Paulo R. Menezes 3 & Alexandre Faisal-Cury 3
Received: 29 December 2014 / Accepted: 22 April 2015 # Springer-Verlag Wien 2015
Abstract Cannabis is the most commonly used illicit drug during the perinatal period and has potential risks to the fetus. The purpose of this study is to estimate the 1-year prevalence of cannabis use and identify associated factors for a population of low-income pregnant women in Brazil. We performed a cross-sectional analysis of 831 women surveyed using a structured questionnaire to collect sociodemographic, clinical, and substance use history. The 1-year prevalence of antenatal cannabis use was 4.2 %; reported lifetime use was 9.6 %. The presence of a common mental disorder and active tobacco smoking were independently associated with cannabis use, OR=3.3 (95 % CI 1.65–6.59) and OR=6.89 (95 % CI 3.45– 13.8), respectively. Keywords Cannabis . Marijuana . Pregnancy . Pregnant women . Brazil . Mental disorder . Tobacco
Introduction The adverse effects and global burden of health related to cannabis use is significant with approximately 125–227 million who used cannabis in 2012 (UNODC 2014). Of great
* Janet E. Shu [email protected]
Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
Cambridge Health Alliance, 1493 Cambridge Street, Cambridge, MA 02139, USA
Department of Preventive Medicine, University of São Paulo, São Paulo, SP, Brazil
concern, cannabis is the most common illicit drug used during the perinatal period (Hayatbakhsh et al. 2011). The range of cannabis use in the past year varies by region, from virtually nonexistent in Asia, to as high as 42 % in the USA and New Zealand (Degenhardt and Hall 2012). In Brazil, reports of cannabis use within the past year range from 2.0 to 6.9 % (Jungerman et al. 2010). Since tetrahydrocannabinol (THC) has been shown to cross the human placenta and blood-brain barrier (Fride 2008), multiple studies have expressed concern regarding the risks of in utero cannabis exposure. While some studies have found no association with adverse fetal outcomes (Lester and Dreher 1989; English et al. 1997), many have found an association with negative outcomes from infancy into adulthood. These include lower birth weight, smaller head circumference, lower gestational age, neonatal withdrawal symptoms and autonomic changes, childhood and adult cognitive and/or behavioral issues, and increased risk for substance abuse in children in their teens to twenties (Fergusson et al. 2002). Despite these risks, cannabis continues to be prevalent, often with continued use during pregnancy and breastfeeding (Moore et al. 2010). Limited knowledge is available regarding what factors increase risk for cannabis use in pregnancy. Previous studies have found a variety of demographic and risk factors, including cannabis use by the biological father of the child, unmarried marital status, childhood trauma and delinquency, age, parity, education, and comorbid substance use (Fergusson et al. 2002; El Marroun et al. 2008). Few studies examine the prevalence of cannabis use in low-income pregnant women in Brazil. Several studies using the same dataset found 4 % prevalence of marijuana use (Mitsuhiro et al. 2006), an association with number of sexual partners and marijuana use (Bessa et al. 2010), and an association of black race with marijuana use during the third trimester of pregnancy in adolescent mothers (De Moraes Barros
J.E. Shu et al.
et al. 2006). The purpose of our study is to describe the 1-year prevalence of cannabis use and correlates of use among lowincome pregnant women living in Brazil.
Statistical analysis The prevalence of cannabis use was calculated. The unadjusted and adjusted odds ratios (OR) with confidence intervals (CI) for cannabis use in the past year were determined using logistic regression. Statistical analyses were performed using Stata version 11 (College Station, TX).
Study design and setting This is a cross-sectional study of 831 women receiving free antenatal care in public primary care clinics in São Paulo, Brazil. A detailed description of the study sample has been published elsewhere (Faisal-Cury et al. 2009). Eligible study participants were low-income pregnant women, aged 16 years or older, between the 20th and 30th weeks of a singleton pregnancy, and those who attended antenatal care appointments in the public primary care clinics of 10 chosen administrative districts, between May 2005 and March 2007. Eligible women were invited to participate in the study and informed consent was obtained during a private face-to-face interview. Exclusion criteria included history of psychosis and refusal to participate. A total of 831 out of 868 (95.7 %) pregnant women were included in the analysis. All procedures were approved by the ethics committees of the University Hospital and of the Health Secretariat of the city of São Paulo. Measurements A detailed structured questionnaire was used to collect information on sociodemographic characteristics of participants, including age, place of birth, marital status, ethnicity, education, religion, family income, and social support. Questions also asked about whether the pregnancy was planned, presence of complications, previous psychiatric treatment, and use of tobacco and cannabis. For the cannabis use question, participants were asked BHave you used cannabis in your life?^ Among those answering Byes,^ participants were then asked: BHave you used cannabis in the past 12 months?^ An answer of Bdaily use, 1–3 times weekly, less than once per week/more than once per month, and less than once a month^ counted as Byes^ for cannabis use. The Self-report questionnaire-20 (SRQ-20) was used to identify the presence of antenatal common mental disorder (CMD). The questions used to identify CMDs took into account overlapping symptomatology of different mood disorders by clustering depressive, anxious, and somatic symptoms in order to detect the presence of a clinically relevant psychiatric disorder. The cutoff point of the SRQ-20 for this study was set at 7/8. The SRQ-20 has been validated in primary care settings in Brazil, with 86 % sensitivity and 80 % specificity for the detection of CMDs (Mari and Williams 1985).
Results Table 1 shows the sociodemographic and clinical information of the study sample and the prevalence of cannabis use in unadjusted and fully adjusted populations. The mean age of the participants was 25 years (±6.0). Most participants were born outside São Paulo (54 %), married or living with a partner (75 %), and had completed 8 years of formal education (51 %). Participants reported their skin color/race as white (45 %) or black/ mixed/other (55 %). In the entire sample, the 1-year prevalence of antenatal cannabis use was 4.2 %, while reported lifetime use was 9.6 %. The presence of a CMD and active tobacco smoking significantly increased risk of cannabis use. Only 2.5 % of patients without a CMD used cannabis during the antenatal period, versus 7.8 % of patients with a CMD (p1200 Marital status Single Married or lives with partner Friends in the community No Yes Planned pregnancy No