I just found out yesterday I am 4 weeks pregnant, I am a regular weed smoker I usually smoke once a day at night right before bed just a couple hits out of my pipe so I basically smoked every night for the first 4 weeks of my pregnancy because I did not know. I'm just wondering how much it would have hurt the fetus? I'm really freaking out.. I feel so guilty. Please help.

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    I might suggest calling your doctor about this.
    – Taryn
    Commented Jan 15, 2015 at 21:32
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    If you read the Tour then you may realize that Parenting SE isn't about giving "negative answers". If you don't like the types of answers your question may illicit, then you may want to have your answer be less personal. For instance, your entire question could (and should?) be: What are the known effects, if any, of smoking marijuana during early pregnancy? Your personal details, in this case, don't affect the answer, and removing them will preclude you from having to preemptively accuse of judgmental responses.
    – user11394
    Commented Jan 16, 2015 at 2:20
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    First of all, stop smoking. Then call your doctor. Probably there'll be no damage as you don't smoke much. Congratulation for the good news :)
    – algiogia
    Commented Jan 16, 2015 at 9:24
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    I've known plenty of people who've smoked various substances (some very heavily) and all had perfectly healthy children. And honestly, a doctor can't do anything apart from offer you advice. His advice will be "stop smoking it now". That's all. Don't worry, everything will be fine.
    – Octopus
    Commented Jan 17, 2015 at 1:23

5 Answers 5


First off, congrats :)

Go to the doctor and be honest! My wife and I did the same thing during her first pregnancy. Our daughter, now 5, is as bright and cheery and happy and healthy as any other kid in her class.

Additional stress isn't good for either your or your baby. So calm down first. Only then can you make rational adult decisions.

Just make sure you stop smoking now. The longer you continue to put weed in your system, the more damaging it becomes.

  • Comments are not for extended discussion; this conversation has been moved to chat. Commented Apr 12, 2018 at 1:23

Quit freaking out. That's the first thing to do.

People get pregnant, they have kids. This is normal. It may not be normal for you, but, it is, in general, a fact of life.

So, you can do it. The challenge is to be the best mother you can be, and that means starting now to make choices that are good choices for both you, and the baby.

Once you start making choices that are positive, the freaking out will diminish, and the control will return. So, make a good decision, and a good candidate for a good decision, is to visit your doctor, speak to your close family, or friends.

After that, it's all just a sequence of making informed, controlled, and planned decisions.

Sure, there will be more occasions to freak out in the future... but action and good decisions are what cure that.


One thing to consider is that usually "4 weeks pregnant" counts two weeks before you actually ovulated. The next five days (well, possibly more, depending on when you ovulated, but average is 5 - 6), the fertilized egg (now called a zygote) will travel from the Fallopian tube down to the uterus, where the now multicellular blastocyst will attach itself to the lining of your uterus and will get nourishment from the blood built up there. So, really, there may have been some amount of THC in that blood-rich lining, but it's not exactly like the baby's blood supply was directly linked to yours until approximately the 17th day following conception, when both fetal and maternal blood vessels are functioning, and true placental circulation is established.

So, if you were told you were 4 weeks pregnant (though I don't know how you determined that), remember that usually pregnancy is measured by the first day of the last period, thus giving you two "empty" weeks, and from there, it takes about 17 days to start truly exchanging blood drugs with the fetus.

From the day of fertilization, the beginnings of the brain start to form on day 22, so about a week after you first miss your period.

Please take this into consideration when you consider the effect of smoking a "couple of hits" from your pipe every night. And please consider that this very thing has probably happened to hundreds of thousands of women over the past four and a half decades.

Embryology Week 4


One of the more recent studies of fetal development in mothers using marijuana does suggest that it not only affects fetal growth and brain development in the short term, but may cause changes in the brain that last a lifetime.

Comparing it to fetal alcohol syndrome, though, shows that it is significantly less severe.

This article summarizing the results provides the following information:

Children whose mothers use marijuana during pregnancy have a higher risk of stunted growth and of developing ADHD, anxiety, and depression later in life.


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.


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.


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.”

Unfortunately there's little data that would be able to provide insight into how much damage your drug use may have caused, but given that you've stopped, and given other's experiences, chances are good you will have a happy, healthy baby.

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    When downvoting, please consider posting a comment on how this answer is "not useful" so I can improve it. Thanks!
    – Adam Davis
    Commented Jan 16, 2015 at 22:48
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    I suspect that any downvotes (I don't have enough rep on this stack to tell how many you have received) is just based on a heartfelt desire to put the OP's mind to rest. A wee bit of weed during the "Oops, I didn't know" phase is so unlikely to be actually problematic, that those studies strike me (and maybe us) as being alarmist. Commented Jan 17, 2015 at 12:17
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    I'd love to upvote this, simply because you actually cite evidence, unlike the other higher-voted answers. Unfortunately, the papers you cited don't necessarily seem applicable to the first few weeks of pregnancy, and instead seem generalized throughout the whole pregnancy. Definitely doesn't deserve a downvote, imo, though.
    – user420
    Commented Jan 18, 2015 at 18:35

In addition to "go to the doctor", instead of just stopping the use of marijuana, ask the doctor whether stopping abruptly might be damaging, and if so, what is the best way to stop the use slowly.

I'm quite sure that abruptly stopping cigarette smoking is not recommended because it upsets your body which affects the child, so I would think that marijuana might be the same - but your doctor should know.

  • Going cold turkey on cigarettes is physically upsetting if you smoke a lot - chain smoking for example. If OP really used to smoke a small amount, this should not apply.
    – Stephie
    Commented Jan 17, 2015 at 16:51

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