What Determines Egg Quality With Female Fertility? | Dr. Natalie Crawford & Dr. Andrew Huberman
00:00:00.000 | I'm curious whether or not we can just touch on a few of the things that a lot of people
00:00:07.040 | wonder about in terms of egg quality.
00:00:10.040 | And if they touch on sperm quality, maybe we can also just mention that.
00:00:14.080 | But for instance, does cannabis, either by edible or by smoking cannabis, impact egg
00:00:24.100 | quality in either direction?
00:00:27.040 | Alcohol would be the next.
00:00:28.520 | And then I'm going to assume, and I have to do this strictly because of what I understand
00:00:33.660 | about drugs of abuse like cocaine and amphetamine, methamphetamine, that none of those can be
00:00:38.840 | good for systems of the body because they create so much stress for the body.
00:00:43.680 | But let's just say alcohol and cannabis.
00:00:46.500 | I read a statistic when researching the episode on cannabis that shocked me, which is that
00:00:51.240 | 15%, 1.5%, not 1.5, 15% of American women, at least in this one study, survey, reported
00:01:02.140 | having consumed or smoked cannabis during known pregnancy, which is wild.
00:01:09.000 | Wild.
00:01:10.000 | Unless, of course, I'm just naive and THC is not harmful to the fetus, but I have a
00:01:16.640 | hard time believing that.
00:01:18.400 | So what gives?
00:01:19.960 | And there, I actually just threw in fetal development.
00:01:23.760 | So is cannabis, is alcohol bad for egg quality?
00:01:29.140 | So they're different things and they're the same thing in one.
00:01:30.920 | So let's answer them each individually.
00:01:32.400 | So we'll go with the one that everybody knows and has accepted now that they wouldn't have
00:01:35.760 | accepted 40 years ago, right?
00:01:37.440 | Smoking cigarettes.
00:01:38.440 | So that's obviously bad.
00:01:40.480 | Decreases the number of eggs you have in the vault.
00:01:42.560 | Smoking cigarettes actually gets into your vault, decreases the number that you have.
00:01:45.160 | You have a higher chance of going into menopause earlier, and it increases the risk of having
00:01:50.880 | abnormal chromosomes, which is what we really think about when we think about egg quality,
00:01:55.120 | right?
00:01:56.120 | Impacting those meiotic spindles inside the eggs, which hold the chromosomes in their
00:01:59.760 | perfect position.
00:02:01.480 | They are associated, they get wear and tear from things that cause inflammation or are
00:02:06.840 | toxic.
00:02:07.840 | So cigarette smoke, we know, decreases egg quality, egg quantity, increases miscarriage,
00:02:12.800 | and then, of course, has fetal impacts.
00:02:14.960 | Could I just ask you, because when we talk about – there's nicotine, which itself
00:02:19.760 | is not carcinogenic, and then there's the smoking process, which brings in a bunch of
00:02:23.040 | other things.
00:02:24.440 | The question I know is burning in everybody's mind is vaping, right?
00:02:28.600 | Because vaping is – I'm very bullish on this.
00:02:32.000 | I mean, it's very clear that the chemicals associated with vaping are just oh so bad
00:02:35.400 | for everybody's health, but it's distinctly different from saying that nicotine is bad
00:02:41.520 | for one's health.
00:02:42.520 | I mean, it can be, but without doing too much of a deep dive, are there any data that show
00:02:47.720 | that vaping is bad for egg quality?
00:02:49.840 | Of course, there's not as much data because it just hasn't been around as long, but yes,
00:02:54.840 | vaping definitely has chemicals that looks like it's associated with poor success rates
00:03:00.080 | in IVF cycles.
00:03:01.200 | And that's really kind of one of the most finite measures of egg quality we can see
00:03:04.800 | because we're really testing the egg at a level in a lab versus just are you getting
00:03:10.360 | pregnant naturally.
00:03:11.360 | And sorry to interject again, but any time a conversation like this comes up, especially
00:03:14.880 | between two people in the health science space, there are these shouts because I hear them
00:03:20.080 | literally, where people say, "Well, listen, I vaped every day and I've had three healthy
00:03:26.520 | babies."
00:03:27.520 | And I think my response is always, okay, there's going to be a distribution of responses.
00:03:30.840 | And then, of course, how much healthier could your babies have been had you not vaped during
00:03:35.560 | pregnancy or vaped prior to pregnancy or – I mean, I think these are the key issues that
00:03:39.840 | like you can't rewind the clock as far as I know, right, in the absence of a time machine.
00:03:44.480 | You can't rewind the clock.
00:03:45.480 | So I mean, basically everything you're saying is that smoking cigarettes or vaping nicotine
00:03:51.800 | just can't be good for egg quality.
00:03:53.840 | We know that.
00:03:54.840 | We know that it's not good for getting pregnant.
00:03:57.040 | We know that it's not good for sperm.
00:03:59.400 | And therefore, we also know it's going to impact pregnancy rates.
00:04:04.000 | Things like cannabis, right, decreases sperm production, decreases sperm motility, changes
00:04:09.040 | sperm morphology, the shape of it, changes the DNA, increases the fragmentation of the
00:04:13.880 | DNA.
00:04:14.880 | If your partner uses cannabis and you get pregnant, you have a higher chance of miscarriage
00:04:20.520 | because of the sperm association with the cannabis.
00:04:23.720 | Now –
00:04:24.720 | Edible cannabis as well as smoked cannabis.
00:04:25.720 | I don't know, right, because you can't study something that's illegal.
00:04:27.920 | So a lot of this data is just more new and a lot of it's going to be observational.
00:04:32.760 | Even in states like Colorado and California where cannabis is essentially legal, I'm
00:04:39.380 | assuming there are more data.
00:04:40.760 | But okay, so smoking and/or vaping nicotine, cannabis, either edible or smoked, very likely
00:04:52.500 | detrimental to egg quality and sperm quality, which is not to say that one can't conceive.
00:04:57.600 | It just means that the quality of your baby, your child, will not be as high as the quality
00:05:04.480 | of that baby if you didn't do that.
00:05:06.680 | Is that right?
00:05:07.680 | And I'm not trying to demonize anyone that did do this during pregnancy.
00:05:11.000 | A lot of people didn't know.
00:05:12.360 | But this is really about people trying to make choices in anticipation of future pregnancy.
00:05:17.000 | Yeah.
00:05:18.000 | And when you're trying to set yourself up for success, because we know infertility is becoming
00:05:22.320 | more common.
00:05:23.320 | We don't always know who is going to have it.
00:05:25.800 | And when you find yourself in that position specifically, you now want to optimize everything
00:05:31.200 | you can.
00:05:32.200 | So if there's something that is going to make the sperm quality worse and the egg quality
00:05:36.360 | worse and your success with treatment lower and your miscarriage rate higher, we're going
00:05:41.640 | to recommend that you not do it.
00:05:43.580 | If you're trying to get pregnant naturally, all these things correlate over.
00:05:46.920 | But of course, there's always going to be outliers and exceptions.
00:05:50.360 | I'm going to sit here and tell you that the odds of getting pregnant at age 43 are less
00:05:54.340 | than 3% per month.
00:05:56.160 | And every single person is going to be like, "But my Aunt Barbara or I know this person
00:05:59.880 | who did," because 3% is not zero.
00:06:02.560 | And you're talking about natural pregnancy there by intercourse.
00:06:05.840 | Old-fashioned way, yes.
00:06:07.440 | Right.
00:06:08.440 | But yes, so people will get pregnant.
00:06:10.160 | People will have healthy children who do have exposures to nicotine, to cannabis, even to
00:06:15.240 | alcohol.
00:06:16.240 | Even though we know that alcohol can cause fetal alcohol syndrome, 0% of alcohol should
00:06:20.980 | be the acceptable level in pregnancy.
00:06:24.720 | And then does alcohol impact fertility?
00:06:27.040 | Such a complicated question, and this is probably due to the amount you consume and the frequency
00:06:32.680 | of which you consume it.
00:06:34.760 | Alcohol is a toxin that your liver must filter out, and we know it causes inflammation.
00:06:39.600 | Anybody who's had a fun night with alcohol knows they can wake up the next day and they
00:06:43.200 | feel different.
00:06:44.840 | Their body is processing that alcohol.
00:06:47.720 | And that inflammation, especially if it's chronic, chronic exposure, we know chronic
00:06:53.480 | inflammation is one of the things that we see impacting egg quality and sperm quality.
00:06:58.560 | So certainly if you enjoy alcohol, it should be something that is done in moderation, one
00:07:03.740 | or two drinks a week at the most, and you should not do it at all once you find out
00:07:08.520 | you're pregnant.
00:07:09.300 | [MUSIC]