Pregnancy

Results
Rates of reported cannabis use in pregnancy increased from 1.3% to 7.5% over the study period with no appreciable change in slope after legalisation in 2018. Infants of mothers reporting cannabis use in pregnancy were more likely to have major anomalies and a 5-minute Apgar score ≤ 7, require NICU admission, and had lower birth weight, head circumference, and birth length than infants of mothers not reporting cannabis use. These associations did not differ before and after legalisation.

Conclusions
Reported cannabis use during pregnancy is associated with early postnatal complications and reduced fetal growth, even after taking into account a range of confounding factors. Rates of reported cannabis use during pregnancy increased over the past five years in Nova Scotia with no apparent additional effect of legalisation.

In human studies, the preponderance of evidence suggests that prenatal cannabinoid exposure is predictive of several adverse neonatal outcomes, most notably FGR Fetal growth restriction and LBW low birth weight.
There is thus an urgent need to better understand the mechanistic links between these prenatal developmental events, their impact upon neurodevelopmental pathology and risk factors and how exposure to cannabinoids might synergistically modulate these complex interrelationships.
 

Maternal cannabis use in pregnancy and child neurodevelopmental outcomes We link pregnancy and birth data to provincial health administrative databases to ascertain child neurodevelopmental outcomes. We use matching techniques to control for confounding and Cox proportional hazards regression models to examine associations between prenatal cannabis use and child neurodevelopment. 
 

Marijuana Use During Pregnancy Linked To Autism In Children: Study
 

“No amount of marijuana use during pregnancy or adolescence is safe,” said Surgeon General Jerome Adams at a press conference.

Significant effects of prenatal cannabis exposure have been found on children's sleep, cognitive functions (memory and scholastic skills), as well as on executive (frontal lobe) functions (reasoning, attention, impulsivity, and motivation), and affective (depression) and anxiety symptoms throughout the stages of development. Following the presentation of two case vignettes, we integrate the published information on outcomes of maternal use of cannabis during pregnancy on the developing fetus and the "soft" neurological deficits and neuro-behavioral disturbances manifested by them from early childhood and evolving to peaks in adolescence. Taken together, these data serve to define what we call a heretofore unspecified "fetal cannabis spectrum disorder".

Large-scale, longitudinal studies of humans whose mothers smoked marijuana once or more per week and experimental work on rodents exposed to cannabinoids in utero have yielded remarkably consistent intellectual and behavioral correlates of fetal exposure to this drug. Some exposed individuals exhibit deficits in memory, cognition, and measures of sociability. These aberrations appear during infancy and persist through adulthood and are tied to changes in the expression of multiple gene families, as well as more global measures of brain responsiveness and plasticity. Researchers currently consider these perturbations to be mediated by changes to the endocannabinoid system caused by the active compounds in cannabis. 

The importance of the published findings and the emerging research regarding the potential negative effects of marijuana on brain development are a cause for concern despite the limited research and are the basis for the following recommendations:

1. Women who are considering becoming pregnant or who are of reproductive age need to be informed about the lack of definitive research and counseled about the current concerns regarding potential adverse effects of THC use on the woman and on fetal, infant, and child development. Marijuana can be included as part of a discussion about the use of tobacco, alcohol, and other drugs and medications during pregnancy.
2. As part of routine anticipatory guidance and in addition to contraception counseling, it is important to advise all adolescents and young women that if they become pregnant, marijuana should not be used during pregnancy.
3. Pregnant women who are using marijuana or other cannabinoid-containing products to treat a medical condition or to treat nausea and vomiting during pregnancy should be counseled about the lack of safety data and the possible adverse effects of THC in these products on the developing fetus and referred to their health care provider for alternative treatments that have better pregnancy-specific safety data.
4. Women of reproductive age who are pregnant or planning to become pregnant and are identified through universal screening as using marijuana should be counseled and, as clinically indicated, receive brief intervention and be referred to treatment.
5. Although marijuana is legal in some states, pregnant women who use marijuana can be subject to child welfare investigations if they have a positive marijuana screen result. Health care providers should emphasize that the purpose of screening is to allow treatment of the woman’s substance use, not to punish or prosecute her.
6. Present data are insufficient to assess the effects of exposure of infants to maternal marijuana use during breastfeeding. As a result, maternal marijuana use while breastfeeding is discouraged. Because the potential risks of infant exposure to marijuana metabolites are unknown, women should be informed of the potential risk of exposure during lactation and encouraged to abstain from using any marijuana products while breastfeeding.
7. Pregnant or breastfeeding women should be cautioned about infant exposure to smoke from marijuana in the environment, given emerging data on the effects of passive marijuana smoke.
8. Women who have become abstinent from previous marijuana use should be encouraged to remain abstinent while pregnant and breastfeeding.
9. Further research regarding the use of and effects of marijuana during pregnancy and breastfeeding is needed.
10. Pediatricians are urged to work with their state and/or local health departments if legalization of marijuana is being considered or has occurred in their state to help with constructive, nonpunitive policy and education for families.

Researchers had two women conduct "mystery caller" phone conversations with employees at 400 dispensaries across the state, telling them that they were eight weeks pregnant and suffering from morning sickness. During the majority of those calls, the employees recommended the women use cannabis products.

1. Legalizing cannabis has been shown to increase the rates of motor vehicle accidents.
2. Cannabis use is a risk factor for mental illness.
3. Inhaled Cannabis use is a risk factor for respiratory infections.
4. Cannabis use increases the rate of vascular disease. Cannabis is the third most often identified drug of abuse
5. Cannabis use during pregnancy has been associated with increased risk of adverse birth outcomes
6. Legalization of cannabis has been shown to increase cannabis exposure in the pediatric population.
7. Heavy cannabis use is associated with diminished lifetime achievements.
Doctors must educate the public about the potential harm cannabis causes with heavy, and possibly moderate, widespread use just as they do about the dangers of tobacco use. Tobacco use has declined in the United States in large part because of the knowledge the public now holds about its adverse effects, as opposed to legislative action.

In a new study, researchers in London, Ontario found that women who used marijuana while pregnant were almost three times more likely to have an infant with low birth weight than women who did not use marijuana.

Here are just a few of the health effects you may want to know:

• Marijuana use directly affects the brain—specifically the parts of the brain responsible for memory, learning, and attention.
• The compounds in marijuana can affect the circulatory system and may increase the risk of heart attacks and strokes.
• Smoking marijuana can lead to a greater risk of bronchitis, cough, and phlegm production.
• Marijuana users are significantly more likely than nonusers to develop chronic mental disorders, including schizophrenia. Schizophrenia is a type of mental illness where people might see or hear things that aren't really there (hallucinations).
• Eating foods or drinking beverages that contain marijuana have some different risks than smoking marijuana, including a greater risk of poisoning.
• About 1 in 10 marijuana users will become addicted. For people who begin using before the age of 18, that number rises to 1 in 6.
• Some research shows that using marijuana while you are pregnant[288 KB] can cause health problems in newborns—including low birth weight and developmental problems.
• Marijuana use can slow your reaction time and ability to make decisions when driving[271 KB].

Alcohol use during pregnancy can cause fetal alcohol spectrum disorders (FASDs), which are physical, behavioral, and intellectual disabilities that last a lifetime. FASD is 100% preventable.

For the researchers of the study, the results present a “a major public health concern” as a number of pregnant women would report taking marijuana to alleviate morning sickness or nausea – without knowing of the adverse side-effects.

http://www.sciencedirect.com/science/article/pii/S0890623816300715#    

Highlights

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Marijuana increases the risk of spontaneous preterm birth independent of cigarette smoking status and socio-economic status.

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Women who continue to use marijuana at 20 weeks’ gestation are five times more likely to deliver preterm than those who do not.

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The rate of early SPTB is higher amongst women who continue to use marijuana at 20 weeks’ gestation.

 But at a bare minimum, these findings suggest we should be avoiding recreational cannabis use during pregnancy. 

Given these statistics.... is legalization worth the consequences....
Cannabis has been found to be the most frequently used drug in the U.S. after alcohol, tobacco and caffeine. 
The risk of developing addiction associated with cannabis use has been reported to increase to about 17% among those who start using marijuana in adolescence, and to 25-50% among those who smoke marijuana daily.
The long-term effects of marijuana use include altered brain development and cognitive impairment, including impaired neural connectivity in specific brain regions, decreased activity in prefrontal regions, and reduced volumes in the hippocampus.
Cannabis is most commonly consumed through smoking, a route of drug delivery that predictably has a variety of negative effects on pulmonary function. Smoke from marijuana combustion has been shown to contain a number of carcinogens and cocarcinogens, as well as many of the toxins, irritants, and carcinogens as tobacco smoke.  Additionally, marijuana smokers tend to inhale more deeply and hold their breath longer than cigarette smokers, which leads to a greater exposure per breath to “tar” (the carcinogenic solids in smoke). Regular smoking of marijuana, in the absence of tobacco, produces visible and microscopic injury to the large airways
http://www.asam.org/docs/default-source/publicy-policy-statements/mariju...

"We found moderate evidence that maternal use of marijuana during pregnancy is associated with negative effects on exposed offspring, including decreased academic ability, cognitive function and attention. Importantly, these effects may not appear until adolescence.

State of the Science   190 resources
Several problems are associated with marijuana use during pregnancy, because prenatal exposure influences brain development and can result in permanent cognitive impairment. [35] Cognitive deficits resulting from prenatal exposure include inattention; impulsivity; and impairment in learning, memory, and certain aspects of executive functioning. [36] In addition, prenatal exposure to cannabis has been associated with reduction of fetal growth. [37]
For many years, the myth of smoked cannabis being "healthier" or "no worse" than smoked tobacco was perpetuated by pro­marijuana groups. Both smoked cannabis and tobacco contain approximately 4000 chemicals and that these chemicals are essentially identical in both plants.In another recent review, [23] the authors concluded that "smoking of cannabis is not medically recommended due to the potential respiratory tract, dangers of noxious compounds such as polycyclic aromatic hydrocarbons, tar and carbon monoxide."
 
 

Appendix

Changes in Marijuana Use Patterns, Systematic Literature Review, and Possible Marijuana-Related Health Effects

Recent attention has been focused on the long-term impact of cannabis exposure, for which experimental animal studies have validated causal relationships between neurobiological and behavioral alterations during the individual's lifetime.