Learning disabilities, behavioral and cognitive problems, brain damage, premature birth, low birth weight, miscarriage, and stillbirth -- just some of the potential side effects of smoking marijuana during pregnancy. Is it really worth it?
Pot Smoking in Pregnancy Tied to Increased Risk of Stillborn
Columbus OBGYN advises that expectant mothers who smoke marijuana may actually by tripling their risk for a stillbirth (fetal death after 20 weeks of pregnancy).
This risk is also reported to be increased by smoking cigarettes, using other legal and illegal drugs and being subjected to secondhand smoke. Stillbirth risk is heightened whether moms are exposed to just pot or in combination with other substances.
In fact, studies have revealed that 94 percent of mothers who had stillborn babies consumed one or more of these substances. Even when findings are regulated for cigarette smoking, marijuana use is associated with an increased risk of stillbirth.
Among drugs, signs of marijuana use were most often discovered in the umbilical cord blood from stillborn babies. And because marijuana use may be increasing with increased legalization, the relevance of these findings may increase as well.
Your Columbus OBGYN feels that both obstetric care providers and the public should be aware of the connection between both cigarette smoking, including passive exposure, and recreational/illicit drug use, and stillbirth. And although the numbers were lesser related to prescription narcotics, there appears to be an association between exposure to these drugs and stillbirth as well.
It’s clear that there is an increased risk of stillbirth with women who are smoking marijuana. Some of it is overlapping with smoking cigarettes, and we know that cigarette use is also associated with stillbirth. So the more a woman smokes, the higher the risk.
Studies found that in 94 percent of the stillbirths tested, results were positive for an illegal drug, and the most common drug discovered was marijuana, which was associated with a 2.8-fold increase for stillbirth.
How strong the association is between all these different drugs and stillbirth isn’t easy to pin down. In pregnancy it’s sometimes difficult to determine the exact cause of things, but there is clearly some connection there.
Although all the evidence isn’t in, your Columbus OBGYN advises women not to smoke, use drugs or drink when planning to become pregnant or when expecting. The same is true for secondhand smoke; it’s probably best not to be around it, but if you’re married to a partner who smokes or you’re in a family of smokers, it’s going to be difficult to manage.
Effects of Marijuana Use During Pregnancy
During pregnancy, women who smoke marijuana expose their developing fetuses to the drug when it passes to the fetal bloodstream inside the placenta. There is considerable disagreement among medical professionals about the impact of marijuana on fetal development, in part because women who use the drug also commonly use other substances that can alter the development process. Still, current evidence indicates that use of marijuana during pregnancy can potentially produce negative effects on the viability of that pregnancy, as well as negative effects on the long-term learning capabilities of children exposed to the drug in the womb.
An expectant mother’s bloodstream does not connect directly to the bloodstream of her developing fetus. Instead, both of these bloodstreams flow through opposite sides of the placental barrier, a grouping of tiny blood vessels inside the placenta. Oxygen, nutrients, and a variety of other substances pass from the mother’s blood through the placental barrier, and then into the fetal bloodstream. At the same time, carbon dioxide and other waste products pass from the fetus’s blood through the placental barrier, and then into the maternal bloodstream. When an expectant mother uses marijuana, the drug’s active ingredient (called tetrahydrocannabinol or THC) passes through the placental barrier along with various other materials, and thereby enters the fetal circulation.
Potential for Pregnancy Complications and Premature Birth
Just like cigarette smoking, marijuana smoking elevates the amount of carbon dioxide and carbon monoxide circulating in a pregnant woman’s bloodstream. Elevations in these substances lead to a reduction in the blood’s oxygen content; in practical terms, this means that there will be less oxygen available to pass through the placental barrier and enter the system of a developing fetus. One potential consequence of this oxygen depletion is an increased risk for a miscarriage in the first 20 weeks of pregnancy. According to a study published in 2012 in the Journal of Biological Chemistry, marijuana use can also potentially trigger changes inside the placenta that contribute to the onset of preeclampsia, a dangerous pregnancy complication involving high blood pressure (hypertension) and the abnormal presence of protein in an expectant mother’s urine.
Marijuana use may also increase a woman’s risks for premature labor and birth of a child before a pregnancy reaches its 37th week. Children born prematurely have heightened risks for a variety of serious problems, including vision difficulties, hearing difficulties, jaundice, bleeding in the brain, unusual susceptibility to infection, cerebral palsy, decreased or delayed development of mental function, and a form of interrupted breathing called apnea.
Potential for Low Birth Weight
Along with the potential for premature birth, children born to marijuana-smoking mothers may have increased risks for being born at a weight of less than five pounds, eight ounces. By standard medical definition, doctors consider children born below this limit to have an unusually low birth weight, whether or not they are born prematurely. When viewed from a long-term perspective, children born below the low birth weight threshold have increased risks of developing heart disease, hypertension, and type 2 diabetes, a condition characterized by the onset of blood glucose control problems in later life.
Potential for Learning Impairment
Children born to marijuana-smoking mothers apparently have increased risks for developing learning problems, the American Pregnancy Association reports. Specific problems that may occur include delayed development of age-appropriate skills and a disruption of executive function, a term doctors use to describe the exercise of diverse mental abilities such as problem solving, planning, maintaining concentration, effectively using memory, switching between tasks, controlling impulsive behavior, engaging in verbal reasoning, and monitoring one’s actions over time. Impairments in executive function may manifest in ways that are relatively subtle.
As indicated previously, pregnant women who use marijuana also frequently use other substances—such as tobacco and alcohol—that are capable of producing damaging changes in fetal development or the overall course of a pregnancy. For this reason, doctors and researchers have considerable difficulty isolating the pregnancy-related effects of marijuana from the effects of other harmful influences. In addition, even when it does cause problems, marijuana use apparently does not cause them as consistently as, for example, heavy alcohol consumption would. Because of these considerations, pregnant women may sometimes view marijuana use as a relatively “harmless” endeavor. However, from a medical standpoint, it’s unwise to dismiss the potential impact of the drug, especially when it’s used in combination with other harmful substances.
Cannabis during pregnancy endangers fetal brain development
The consumption of Cannabis during pregnancy can impair the development of the fetus' brain with long-lasting effects after birth. Cannabis is particularly powerful to derail how nerve cells form connections, potentially limiting the amount of information the affected brain can process, new research shows.
An increasing number of children suffer from the consequences of maternal drug exposure during pregnancy, and Cannabis is one of the most frequently used substances. This motivated the study, published in the EMBO Journal, conducted in mice and human brain tissue, to decipher the molecular basis of how the major psychoactive component from Cannabis called delta-9-tetrahydrocannabinol or THC affects brain development of the unborn fetus.
The study highlights that consuming Cannabis during pregnancy clearly results in defective development of nerve cells of the cerebral cortex, the part of the brain that orchestrates higher cognitive functions and drives memory formation. In particular, THC negatively impacts if and how the structural platform and conduit for communication between nerve cells, the synapses and axons, will develop and function. Researchers also identified Stathmin-2 as a key protein target for THC action, and its loss is characterized as a reason for erroneous nerve growth. It is stressed that Cannabis exposure in experimental models precisely coincided with the fetal period when nerve cells form connections amongst each other.
According to study leader Professor Tibor Harkany, who shares his time between Karolinska Institutet and the Medical University Vienna in Austria, these developmental deficits may evoke life-long modifications to the brain function of those affected. Even though not all children who have been exposed to Cannabis will suffer immediate and obvious deficits, Professor Harkany warns that relatively subtle damage can significantly increase the risk of delayed neuropsychiatric diseases.
"Even if THC only would cause small changes its effect may well be sufficient to sensitize the brain to later stressors or diseases to provoke neuropsychiatric illnesses in those affected in the future," says Professor Harkany. "This concerns also the medical use of Cannabis, which should be avoided during pregnancy."
The above story is based on materials provided by Karolinska Institutet. Note: Materials may be edited for content and length.
Giuseppe Tortoriello, Claudia V Morris, Alan Alpar, Janos Fuzik, Sally L Shirran, Daniela Calvigioni, Erik Keimpema, Catherine H Botting, Kirstin Reinecke, Thomas Herdegen, Michael Courtney, Yasmin L Hurd, Tibor Harkany. Miswiring the brain: Δ9‐tetrahydrocannabinol disrupts cortical development by inducing an SCG10/stathmin‐2 degradation pathway. EMBO Journal, January 2014
Karolinska Institutet. "Cannabis during pregnancy endangers fetal brain development." ScienceDaily. ScienceDaily, 27 January 2014.
Marijuana Use Causes Early Pregnancy Failure
Marijuana use at the time of conception and early in pregnancy prevents embryos' safe passage from the ovary to the uterus, resulting in early pregnancy failure, suggests a new study in mice. The study appears in the August issue of the Journal of Clinical Investigation.
Marijuana, the most widely used illegal drug among women of reproductive age, binds to 2 receptors -- cannabinoid receptors 1 and 2 (CB1, CB2) -- which are found in the brain and other organs including sperm, eggs, and newly formed embryos. Normally, these 2 receptors are activated by the naturally occurring signaling molecule anandamide. Anandamide formation by the enzyme NAPE-PLD is carefully balanced with its degradation by the enzyme FAAH, resulting in a finely tuned local "anandamide tone" in embryos and the oviduct. This balance is required for normal embryonic development, transport along the oviduct, implantation in the uterus, and full-term pregnancy.
In the current study, Sudhansu Dey and colleagues from Vanderbilt University show that suppression of FAAH activity in the embryos and oviduct elevates anandamide levels, which inhibits embryonic development and prevents embryos from completing their passage to the uterus, causing impaired fertility. They went on to show that administration to the mice of tetrahydrocannabinol (THC), the major psychoactive component of marijuana that like anandamide also binds to CB1, swamps normal anandamide tone, causing implantation of the embryo in the earliest stages of pregnancy to fail. The results of the study show that drugs such as THC persist and swamp these finely tuned signaling systems and as such the use of THC-containing drugs such as marijuana may lead to ectopic pregnancy and/or impaired fertility in women.
In an accompanying commentary Herbert Schuel from the State University of New York discusses the sobering results of this study regarding marijuana's effects on pregnancy outcome and goes on to stress that a number of drugs currently in development or in use to suppress appetite or trigger weight-loss are also known modulators of anandamide signaling and given the results presented in the current study "such drugs need to be carefully evaluated to judge their effects on women of reproductive age and those that are pregnant."
The above story is based on materials provided by Journal of Clinical Investigation. Note: Materials may be edited for content and length.
Journal of Clinical Investigation. "Marijuana Use Causes Early Pregnancy Failure." ScienceDaily. ScienceDaily, 4 August 2006.
Illegal Drug Use and Pregnancy - The risks involved with illegal drug use during pregnancy
The effects of illegal drugs, such as cocaine, can be devastating on a fetus. Unfortunately, many women of childbearing age in the U.S. use some form of illegal drug.
A mother taking illegal drugs during pregnancy increases her risk for anemia, blood and heart infections, skin infections, hepatitis, and other infectious diseases. She also is at greater risk for sexually transmitted diseases. Almost every drug passes from the mother's bloodstream through the placenta to the fetus. Illicit substances that cause drug dependence and addiction in the mother also cause the fetus to become addicted.
A chromatography is a laboratory test performed on a woman's urine that can detect many illegal drugs, including marijuana and cocaine. Both marijuana and cocaine, as well as other illegal drugs, can cross the placenta. Marijuana use during pregnancy may be linked to cognitive and behavioral problems in the baby. Cocaine use can lead to miscarriage, preterm delivery of the fetus, premature detachment of the placenta, high blood pressure, and stillbirth. Infants born to cocaine-using mothers are more likely to have low birth weight and may have an increased risk of sudden infant death syndrome (SIDS). The effects of cocaine on the baby may include, but are not limited to:
Using dextroamphetamine and methamphetamine can cause miscarriage and preterm birth. Newborns exposed to these drugs in pregnancy often have signs of withdrawal, such as jitteriness, trouble sleeping and feeding, as well as later problems with tremors and muscle tone. They may also be at higher risk for SIDS.
Heroin and other opiates, including methadone, can cause significant withdrawal in the baby, with some symptoms lasting several weeks. Babies born to opiate-addicted mothers are at higher risk for apnea (stopping breathing) and SIDS. These babies also have feeding difficulties.
If a woman stops taking illegal drugs during her first trimester, she increases her chances of having a healthy baby.
Cannabis During Pregnancy Impairs Baby's Brain Development
A new study sheds light on how THC causes damage to cells in the growing brain.
Although it doesn’t compare to fetal alcohol syndrome, cannabis exposure in the womb can cause any number of problems.
Children whose mothers use marijuana during pregnancy have a higher risk of stunted growth and of developing ADHD, anxiety, and depression later in life.
According to the Substance Abuse and Mental Health Services Administration (SAMHSA), more than 10 percent of unborn children in the U.S. and Europe have been exposed to cannabis.
Cannabis is one of the oldest domestic crops known to man, having co-evolved with humans for millennia, and it’s probable that many ancient cultures used the drug. However, modern breeding and cultivation techniques have dramatically boosted the plant’s levels of the psychoactive chemical Tetrahydrocannabinol (THC). THC crosses the placenta very easily, so when a pregnant mother uses the drug, so does her child.
Learn About Marijuana Abuse & Addiction »
The effects that THC can have on a developing fetus are highlighted in a research study published yesterday in The EMBO Journal. The study was conducted by a team from Sweden, Austria, Germany, Finland, the UK, and the U.S., and led by Professor Tibor Harkany at the Karolinka Institutet (KI) in Sweden.
The Devil Is in the Details
Growing a baby from a single cell is an astonishingly complex task. As the fetal brain develops, each cell must grow, migrate to the correct place, form into the correct shape, and successfully make as many as 10,000 connections with other cells. To reach other cells, each nerve cell grows a long, thin stalk called an axon, the end of which fans out to form many links.
This process requires a carefully-timed, intricate cascade of chemical signals. And it turns out that endocannabinoid, a signaling chemical in the body that THC mimics, is one of these. When THC enters the body, it interferes with endocannabinoid’s actions, competing with it for binding sites on target cells and generally getting its way.
To test THC’s effects on the developing brain, Harkany started by exposing pregnant mice to low doses of THC and then examining the brains of their pups.
“The way axons form, bundle, and grow towards their target is impaired,” he told Healthline. Taking a closer look, he found that the number of binding sites for endocannabinoid had increased, and that axons were more likely to clump together. “The growth cones—the motile end tips that guide directional growth—look...different,” Harkany said.
Mice aren’t a perfect model for humans, and we still don't know how different their endocannabinoid system is from that of humans. To confirm his findings, Harkany would have to look at people.
Harkany gathered human fetuses that had been donated to science and tested them to see if they had been exposed to THC. The THC-exposed fetuses had lower body weights and smaller foot length. When he looked inside their brains, he found reduced levels of stathmin-2, a protein involved in learning and memory formation.
Cannabis 'Should Be Avoided' During Pregnancy
Although the brain differences caused by THC exposure are fairly subtle, Harkany warns that their minds' inherent instability is what leaves children at greater risk for developing certain psychiatric conditions later in life.
“Abnormal [axon] organization, even if remaining latent for long periods, might be prone to ‘circuit failure’ if provoked,” he explained. “A ‘double hit’ scenario of failure, when a network advances into a runaway cascade upon a secondary insult, therefore might account for the increased incidence of schizophrenia, depression, and addiction in offspring prenatally exposed to cannabis.”
The take-home message, Harkany feels, is clear. “Cannabis should be avoided during pregnancy. And, if there is a medical indication for the mother then careful cost/benefit analysis should be conducted by medical professionals," he said. "I appreciate the use of medical cannabis, but it should certainly be analyzed whether maternal benefits outweigh potential risk for the baby.”