Marijuana use during pregnancy is a topic of increasing discussion. Understanding the potential impacts of cannabis exposure on both the developing baby and the pregnant individual is important for informed health decisions. This article explores what happens when marijuana is used during pregnancy, detailing the pathways of exposure and the potential developmental, cognitive, and health outcomes that may arise.
How Cannabis Components Affect the Fetus
The primary psychoactive component in cannabis, delta-9-tetrahydrocannabinol (THC), is lipid-soluble, allowing it to readily cross the placental barrier. While the placenta serves as a protective filter, it does not prevent THC from reaching the developing fetus through the maternal bloodstream. This means that when a pregnant person uses cannabis, THC can enter the fetal circulatory system. The fetal brain possesses an endocannabinoid system (ECS), a complex network of receptors and signaling molecules naturally present in the body. This system plays a significant role in brain development, including the differentiation of neural progenitor cells, the guidance of axonal migration, and the formation of synapses. Exogenous cannabinoids, such as THC, can interact with and potentially disrupt this ECS signaling during these critical developmental stages.
Developmental Impacts on the Unborn Baby
Exposure to cannabis components during pregnancy can influence the developing brain and body of the fetus. Studies indicate that prenatal cannabis exposure may affect brain structure, with some research noting alterations in cortical thickness. Changes in gene regulation and expression within the fetal epigenome have also been observed, which align with patterns seen in some neurobehavioral conditions. THC’s interference with the fetal endocannabinoid system can lead to deficiencies in fatty acids like DHA and ARA, essential for neural signaling and the formation of synaptic membranes.
Maternal cannabis use has been associated with growth restriction, particularly in the mid- to late stages of pregnancy. This can manifest as a lower birth weight, with reductions averaging over 150 grams when exposure occurs in the first trimester. Continued cannabis use into the second trimester may lead to a smaller head circumference, potentially reduced by nearly 1 centimeter. A lower birth weight is a significant indicator for potential health and developmental challenges later in life.
Effects on the Child After Birth
The consequences of prenatal cannabis exposure can extend beyond birth, affecting a child’s cognitive and behavioral development into later childhood and adolescence. Children exposed to cannabis before birth may exhibit weaker thinking and planning skills. Specific cognitive abilities, such as attention and memory, can be negatively impacted, with some studies noting deficits in verbal and memory domains in preschool-aged children. While research does not consistently show a reduction in overall global intelligence scores, specific areas of cognitive function can be affected.
Behavioral challenges are also reported in children with prenatal cannabis exposure. These can include hyperactivity, impulsivity, and attention issues. Increased aggression has been observed in some infants, particularly girls. These behavioral patterns can persist into middle childhood and pre-adolescence. Some studies suggest that children exposed to cannabis in utero may show a reduced brain response during anticipation of rewards and could be more likely to report psychotic-like experiences during their adolescent years.
Potential Health Concerns for the Pregnant Person
Cannabis use during pregnancy can also present health considerations for the pregnant person. Studies have linked prenatal cannabis use to several pregnancy-related complications. These include gestational hypertension, preeclampsia, and placental abruption. An association with weight gain that falls outside recommended guidelines, whether too little or too much, has also been noted.
While some individuals may use cannabis to alleviate common pregnancy symptoms like nausea, insomnia, or pain, health organizations advise against this practice. There is no evidence supporting its safety or effectiveness for these purposes during pregnancy. Some research also points to an increased risk of premature birth in infants of cannabis-using mothers.
Guidance for Current and Former Users
Healthcare providers advise discontinuing cannabis use, ideally before conception or as soon as pregnancy is confirmed. There is no established safe amount of cannabis use during pregnancy; health organizations recommend complete abstinence. Maintaining open communication with healthcare providers is important; medical professionals aim to provide support and resources for cessation.
Support for stopping cannabis use can involve strategies like cognitive behavioral therapy (CBT) and motivational interviewing, which help individuals develop coping mechanisms for cravings and identify triggers. Addressing underlying reasons for cannabis use, such as anxiety, depression, or stress, is also beneficial. Healthcare providers can offer alternative treatments or refer individuals to specialists for support. For those who find it challenging to stop, discussing harm reduction strategies with a healthcare professional can be an option. It is also recommended to avoid cannabis use while breastfeeding, as THC can transfer into breast milk.