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Debunking Pregnancy Myths with Dr Lara Friel

05/08/19 Lara A. Friel, MD, PhD, University of Texas Health Medical School at Houston, McGovern Medical School;

Season 1 | Episode 2


Description: When you're pregnant it seems like everyone you know has advice, and it can be overwhelming. You may expect some of the changes that occur during your pregnancy, but others may seem fascinating or even surprising. The internet is full of conflicting information about how to stay healthy during your pregnancy and today we invite Dr. Lara Friel to dispel some of the biggest pregnancy myths and help listeners have the healthiest possible experience for them and their future baby.






>> Dr. Friel: Women do have various cravings for certain food items like pickles or particular fruit like watermelon, but there are some stranger cravings when people want to eat non-food items. One of my patients wanted to eat toilet paper. Now the other patient that I had wanted to eat dirt. Sometimes women want to chew ice or eat ice, so that is a more healthy craving.


>> Narrator: Welcome to the Medical Myths podcast where we set the records straight on today’s most talked about medical topics and questions. On every episode, you’ll hear stories from the frontlines of medical care to help dispel common myths and answer some questions you’ve been itching to ask your doctor. And remember, you can always find more information on this week’s topic and hundreds of others on Now, here’s your host, editor in chief of the Merck Manuals, Dr. Robert Porter.


>> Dr. Robert Porter: Welcome to the Medical Myths podcast where we set the record straight on today’s most talked about medical topics and questions. I’m your host, Dr. Rob Porter editor in chief at the Merck Manuals one of the earth’s most trusted medical resources. On this episode, we welcome Dr. Lara Friel, associate professor of maternal-fetal medicine at the University of Texas at Houston. She’s the high-risk pregnancy specialist at Memorial Herman Texas Medical Center and also authors some of the pregnancy topics in the Merck Manual.


>> Dr. Lara Friel: Hi Rob, very happy to be here.


>> Dr. Porter: Well a lot happens during the 40 weeks of pregnancy, most of which is pretty normal and not distressing to many women but a lot of people worry about what they’re doing during pregnancy, what they’re eating, what their jobs are. Women have gotten advice for thousands of years from their family, from their friends, from their neighbors and now we have the Internet. The Internet has expanded all the conflicting information that women can get about how to stay healthy during pregnancy. So, we’ll have Dr. Friel try to dispel some of the biggest pregnancy myths and help our listeners have the healthiest possible experience for them and their future baby. Some of the bigger sets of myths seem to involve exercise. I remember when I was young they said pregnant women shouldn’t do heavy exercise, they shouldn’t lift heavy things, well now women are lifting weights and running marathons and doing all sorts of things! What’s the truth about this, Dr. Friel?


>> Dr. Friel: This is a great question and I think this is a big question for my patient population. Many women don’t realize that cardiac output increases during gestation and then increases again for labor and then finally one more time when she is pushing. And so really, we should not avoid exercise during pregnancy it may even be more important to exercise in pregnancy compared to than when you’re not pregnant because you are preparing for something that is physiologically difficult. We call it labor, it is not rest time, right? American College of Obstetrics and Gynecology recommends that pregnant women should have 30 minutes of moderate activity on most days of the week and in general, I consider that about five days so 150 minutes total in a week. There are common activities that women can do; walking is considered exercise, aerobics, swimming, some biking, dancing, yoga, weight training, gardening is considered exercise. Women should stay active. 


>> Dr. Porter:  So really if they’ve been doing something before pregnancy, they can pretty much continue it – is that right?


>> Dr. Friel: That’s right, so exercise is very individualized. Women who are more active in their pre-pregnancy state would expect to do more activity in pregnancy. I’ve had an aerobics instructor with a twin pregnancy ask me if she can continue instructing and I, of course, explained about the risks of twin pregnancy and the risk of preterm delivery, but I wanted her to continue at her normal exercise, pay attention to her body – stop exercising if she’s contracting and maintain hydration whenever she’s active, but she was able to maintain healthy exercising for the majority of her pregnancy.


>> Dr. Porter:  Is there a time when women need to cut back or stop, presumably right before delivery you might not want to be doing that kind of thing, is that true?


>> Dr. Friel: There really is no time that she should stop unless there is a complication occuring in her pregnancy. We have people um decrease some activity when they’re having elevated blood pressure, but it is more so if they’re having a complication in pregnancy, not a routine pregnancy.


>> Dr. Porter: Are there any exercise at all then that women should avoid?


>> Dr. Friel: Yes. So, we want to avoid high impact exercises, things that are excessively jarring or can lead to a fall risk. So more of your contact sports like basketball, um, horseback riding, skiing, vigorous racket sports. But, when I was in Detroit, we had a professional women’s basketball team there, it has left us since, but in general contact sports including basketball would be discouraged, but professional athletes do push these limits to some extent and many of the professional basketball players were playing until about 20 weeks of pregnancy.


>> Dr. Porter:  How about Scuba Diving?


>> Dr. Friel: We do not have enough information about pregnant women scuba diving, and that should be avoided as well.


>> Dr. Porter:  And very heavy lifting, I know I’ve seen on television some women competing who are power lifters that are stronger than most men out there, is heavy lifting alright?


>> Dr. Friel: So, women are allowed some light weight training, but yes, heavy weight lifting that requires straining would be discouraged.


>> Dr. Porter:  Still that leaves a whole lot of exercise open to women, and I suspect that the problem is more that women aren’t doing enough than that they’re doing too much.


>> Dr. Friel:     That’s right. I don’t think women are doing enough in the pre-pregnancy state and therefore they are questioning whether they should in pregnancy but they should.


>> Dr. Porter:  And of course, we are not talking about women with medical conditions in which case I presume they should check with their doctor before starting, if they have heart disease, high blood pressure – any other contidtions that any adult would get a check up for before starting an exercise program.


>> Dr. Friel: That’s right; they should always check with their doctor.


>> Dr. Porter:  So how about diet, that seems to be something that is the subject of myths. What are some of the strangest diet recommendations that your patients have mentioned to you?


>> Dr. Friel: I think people have a lot of anxiety about some of the more antigenic foods like peanuts and dairy, and there are some questions about whether they should be eating those during pregnancy and lactation, breast feeding, and actually there is no evidence that they should avoid antigenic foods while they are pregnant or breast feeding.


>> Dr. Porter:  So, if you’re worried about your child developing a peanut allergy there is no point in not eating peanuts is that right?


>> Dr. Friel:That is right, the American Academy of Pediatrics, for approximately a decade, was recommending that we delay giving allergenic foods to children, but now they’ve reversed their opinion and recommend early introduction of allergenic foods to prevent food allergies in children.


>> Dr. Porter:  So, there is certainly no point in the mother avoiding these foods?


>> Dr. Friel: That is correct.


>> Dr. Porter:  How about the amount of food? Should pregnant women be eating for two or should they be worried about gaining too much weight?


>> Dr. Friel:     Most women should be worried about gaining too much weight. 2/3 of the American population is overweight or obese so their pre-pregnancy weight is starting off higher than it should be, and therefore we are not eating for two. Even a normal weight woman should be eating 300 calories more a day, not twice as much in a day. Three hundred calories is not even an extra meal. That would be a snack such as a sandwich, apples and peanut butter or half of a fast food hamburger without any fries or a drink.


>> Dr. Porter:  And wshat kind of food should they be eating?


>> Dr. Friel: In general, I tell my patients that a healthy diet is good for pregnancy as well as pre-pregnancy so we are talking about fruits and vegetables – all the colors of the rainbow to get all the different nutrients from the different colors, lean meats beans, nuts, and seeds.


>> Dr. Porter:  What food should they avoid if any?


>> Dr. Friel: We do have to pay attention to the amount of caffeine we’re ingesting in pregnancy. The American Institute of Gynecology recommends less than 200 mg of caffeine in a day, that is approximately a 12-ounce cup of coffee. We have to be very careful about the kind of coffee we are drinking, going to one of these coffee shops and getting extra espresso shots - we would want to avoid. And we also have to pay attention to how we are getting caffeine in other ways. I think women pay attention to coffee, but they don’t realize that caffeine is also in migraine medications and some desserts including chocolate.


>> Dr. Porter:  And many soda beverages have caffeine in them as well.


>> Dr. Friel: Absolutely, and of course the energy drinks are considered energy drinks beacuase they have extra caffeine.


>> Dr. Porter:  Yes, they are quite caffeinated, you need the energy drink after you have the baby when you’re chasing them around the house.


>> Dr. Friel: And you’re not sleeping well.


>> Dr. Porter: So, Dr. Friel, we’ve heard that mercury in fish is an issue; what do you tell your patients about that?


>> Dr. Friel:Yes, actually, mercury in fish is an issue. We want to eat fish that are lower down on the food chain. Because fish that eat a lot of other fish, that’s where the mercury gets more and more concentrated in their tissues. And so lower mercury fish include salmon, catfish, light tuna, shrimp and we want to avoid shark, swordfish, tilefish, and mackerel because they are eating more other little fish and that mercury gets more concentrated in their bodies.


>> Dr. Porter:  Is there a limit on how much fish that you generally tell your patients, let’s say the safe ones of course not the ones to avoid.


>> Dr. Friel:     With the safe fish it is approximately 12 oz of fish so maybe like two cans of tuna fish in a week.


>> Dr. Porter:  And of course, alcohol, we all know to avoid alcohol, I did look in an old book of old medical remedies and noticed that for vomiting of pregnancy, champagne was one of the recommendations.


>> Dr. Friel: Well that would no longer be a recommendation; there is no safe amount of alcohol in pregnancy.


>> Dr. Porter:  Again, maybe for after the pregnancy. Let’s take a quick break and we’ll be back with more shortly.



Commercial: With a library of calculators, conversion tables, 3D models, and case studies to explore, there’s so much to learn and do on Now back to the Medical Myths Podcast with Dr. Porter. 



>> Dr. Porter:  We are back with Dr. Lara Friel. Now how about cravings, I remember when I was a kid, the joke was always that pregnant women wanted pickles – pickles and ice cream. What is the strangest craving you’ve ever heard from one of your patients?


>> Dr. Friel: I think women do have various cravings and they can be for certain food items like pickles or particular fruits like watermelon those are cravings that I would support in general, there are some stranger cravings when people want to eat non-food items. I’ve had a couple of patients with an eating disorder called Pica, and they were eating things that do not have nutritional value. One of my patients wanted to eat toilet paper. Toilet paper is cellulose material and if it were to be eaten in high volumes, that can get stuck in the intestinal tract and actually block it. It is very hard to get them to not eat these items like this toilet paper overall, but we kept her to just one roll of toilet paper a day, and we wanted to make sure that she was eating food as well, and getting a nutritional diet otherwise. And she did well in the pregnancy.


>> Dr. Porter:  But it is not a recommended source of fiber then?


>> Dr. Friel: [laughter] No it is not. Now the other patient that I had wanted to eat dirt. And unfortunately, a lot of the paint of the paths had lead in it, and dirt in industrial cities can have high levels of lead. She was collecting lead in her body, and this can go to her joints and the fetus. Fortunately, her lead levels did not get so high that we needed to remove the lead during the pregnancy because there is not a lot of data about removing lead during pregnancy.


>> Dr. Porter:  So, we have to discourage any Pica like that?


>> Dr. Friel: That’s right, sometimes women want to chew ice or eat ice, it is hard to eat too much ice or drink too much water in general, although there are diseases where that does happen. So that is a more healthy craving.


>> Dr. Porter:  Now, we’ve talked about diet and exercise; let’s look at the last component of lifestyle – how about sleeping. Is there a specific position women should be sleeping in or should avoid sleeping in for the baby’s safety?


>> Dr. Friel: Actually there is. As pregnancy advances, when a woman is laying on her back the uterus can put quite a bit of pressure on the major blood vessels of the body and prevent return of blood to the heart. And so that would make her feel bad or nauseous and sometimes happens even in the ultrasound unit and many women have to turn slightly. So, many women find that its more comfortable to turn to the left or the right but just not flat on the back.


>> Dr. Porter: I’ve heard that some pregnant women want to avoid getting their hair done because of concerns about the chemicals in hair treatments, is that actually an issue?


>> Dr. Friel:     Most of the time that is not an issue, so there are quite harsh chemicals and solvents used in hair products and nail treatments, but women are not getting a big exposure to those products, they aren’t getting those chemicals into their bodies systemically because it is a short exposure time. So there have been experimental animal studies that show that some of these chemicals were toxic at high levels but these are not the levels that women are getting exposed to in pregnancy.


>> Dr. Porter:  And I suppose that if the chemicals were really that harmful they wouldn’t be put into materials designed to be rubbed into your scalp. Now, what about other chemicals, say women are working in an industry where they might be exposed to chemicals. Are there jobs or are there chemicals where you advise the woman to work in a different department or do a different task?


>> Dr. Friel: Certainly. So, in terms of occupational exposure for the people who are actually doing the hair treatment or nail treatments that exposure is more prolonged because they might even be having daily exposure. Those people would want to wear gloves during the treatments and make sure they are working in a well-ventilated area, so they don’t have the fumes from the solvents.


>> Dr. Porter:  What about women who are radiologists or radiology techs, do they have limits when they’re pregnant that are different otherwise?


>> Dr. Friel: So, there are very strict limits to their exposure even outside pregnancy; they are often wearing wings or badges that are calculating their exposure. And so in general they want to use the precautions that are already set in place; and make sure they have that badge or ring on them at all times so that the exposure is well-known.


>> Dr. Porter:  Are there other lifestyle issues that we haven’t covered so far, how about flying?


>> Dr. Friel: So, there is no evidence that flying is a particular risk in pregnancy. Most women stop flying late into the third trimester, and some airlines say 34 weeks some say 35 weeks, but that’s more because the risk of going into labor is increasing as gestation is advancing.


>> Dr. Porter:  So, not because they are flying, but just because their pregnancy is coming along, they could deliver at any time, and they should really be at their home facility with their doctor rather than travelling in Nepal when they deliver.


>> Dr. Friel:That’s right. I think women don’t realize that all the data that is compiled throughout the pregnancy is useful at the time of delivery, and so, if they are caught away from home it might be important to have a set of their prenatal records, their pre-natal labs, maybe even an ultrasound report in case they are away from their doctors. A new doctor would have none of those records.


>> Dr. Porter:  Of course, and we don’t want to imply there aren’t exceptionally competent doctors in other parts of the world, it’s just that they just don’t have access to the particular patients’ records, which are very helpful.


>> Dr. Friel:That’s right, and I’m not even talking about international travel, even within Texas the various medical centers don’t communicate all of their data to eachother, and so  being out of town wherever you are, can be a disadvantage if something happens to you during the pregnancy of course.


>> Dr. Porter:  Now to wrap up, Dr. Friel, can you tell us the top 3 or 4 things you would like your patients to remember about staying safe and healthy during pregnancy?


>> Dr. Friel: I want women to remain active in pregnancy. If they were not active at all pre-pregnancy they can work up to some exercise slowly, although the 30-minute rule is ideal – a woman could start with 10 minutes of walking in a day and work her way up to 30 over time. I want her to eat a healthy diet. This should include plenty of veggies and fruits. She can eat beans, nuts, and seeds, all the colors or the rainbow, lean protein. And she should be well hydrated. I think many women are not drinking enough water on a daily basis, but we want her to be drinking more water, at least eight glasses a day.


>> Dr. Porter:  Thank you so much, Dr. Friel, where can you advise our listeners to go who want to learn a little more about staying healthy during pregnancy?


>> Dr. Friel: The American College of Obstetrics and Gynecology website has a lot of patient education materials, and they can read more about any of these topics, nutrition, exercise, etc. on that website.


>> Dr. Porter:  And of course, your excellent chapters on the Merck Manual. Well thank you, Dr. Friel, for your time and expertise I think that we have armed our listeners with many tips and tools to experience a healthy pregnancy. So, for more information on these and hundreds of other t medical topics, please visit And remember, as we say at the Merck Manuals


>> Dr. Friel: Medical knowledge is power, pass it on.