If you’re trying to get pregnant, or intend to start trying, being overweight can affect your chances of conceiving and having a healthy baby.
Interestingly, being underweight can also reduce a woman’s fertility. If you're planning to get pregnant in the next year or so, healthy eating and regular exercise can help boost your fertility.
Listen in as Dr. William Ziegler how your weight can affect your ability to get pregnant.
How Weight Can Affect Fertility
William Ziegler, MD, FACOG
William Ziegler, DO., is a specialist in Reproductive Endocrinology and Infertility and is the Medical Director of the Reproductive Science Center of New Jersey. Dr. Ziegler completed a three-year fellowship specializing in reproductive medicine and surgery at the University of Vermont in Burlington. While in Vermont, he had the opportunity to work with nationally known specialists in IVF and ICSI.
Learn more about Dr. William Ziegler
How Weight Can Affect Fertility
Melanie Cole (Host): Does being underweight or overweight affect your fertility? My guest today is Dr. William Ziegler. He’s a board certified specialist in reproductive endocrinology and infertility at the Reproductive Science Center of New Jersey. Welcome to the show, Dr. Ziegler. So, let’s talk first about weight and pregnancy and how are they related? Do you check a woman or a man’s BMI before they start getting pregnant? How is that related?
Dr. William Ziegler (Guest): We look at the partners and, if either one of them are overweight--and we basically go by the BMI when we do calculate that--and either one of them are overweight, we really do address that issue. We go to both the type of activity in which they participate in. In many cases, we have them see or we recommend them seeing a nutritionist.
Melanie: So, how does weight affect fertility?
Dr. Ziegler: Well, we know that within our country, 50% of all Americans are overweight and 30% are basically designated as being obese. We do know from recent studies that obesity accounts for approximately 6% of all primary infertility. And, it’s surprising that even low birth weight women, weight accounts for, again, 6% of damage fertility. So, basically, we’re looking at 12% of the population that have primary infertility from a weigh related etiology. And, the weight itself has to do with the processing of hormones. It can throw off a woman’s cycle--in which we do know that obesity brings to mind hypertension as well as diabetes as well as heart disease. And, it’s very surprising when we approach a patient, and we start to discuss with them the association between obesity or underweight situations and infertility. It’s kind of surprising to them.
Melanie: Does being underweight or overweight affect not only chance of getting pregnant but having a healthy baby?
Dr. Ziegler: Yes, it does. We do know that even with in vitro fertilization, we know that body mass index does play a big role. There was a recent study out that showed that in women who are less than 35 years old, their having a body mass index of less than 30 gave a pregnancy rate of 54%, and if they were over that, that was 40%. This was more dramatic in women who have body mass indexes even higher than 30%. Within pregnancy itself, we do know there is a higher instance for C-section, for hypertension in pregnancy, as well as diabetes. So, looking at these women and getting their body mass index close to what their ideal body weight is or even that our target for those that are obese to be around 110% of their ideal body weight. That is what we shoot for is that helps them help throughout the gestation itself and to help them have a healthy baby.
Melanie: So, do you recommend that women try and lower their BMI if they’re in the obese category before they starting fertility treatments?
Dr. Ziegler: Yes, definitely. And, for those that are underweight, we like for them to even try to attain a 100% of what their ideal body weight should be. So, it helps improve the success rate of any fertility treatment and decreases the risk for the patient as well as the baby throughout pregnancy.
Melanie: We’ve heard about the risks for an obese pregnant woman. What about for an underweight woman? Are there risks to her baby? People don’t think about being underweight as a health hazard.
Dr. Ziegler: Well, being underweight in those individuals, we do know that estrogen level is lower. And, from our menopause patients, we know that with low estrogen, it does affect the bone integrity. So, even in women who are underweight and they want to get pregnant, especially those that have had eating disorders such as anorexia nervosa or even bulimia, those who are very athletic and they’ve been a long-distance runner for a long time or they’re just very aggressive exercisers, that we actually would like to get a bone density scan on them to make sure that their bone integrity is there. If they have osteopenia or if they have osteoporosis, again, that’s something that we need to address because that could affect the way that they carry a pregnancy and their health throughout the pregnancy. Now, when you take a look at the effects of the infant, again, if this is from a malnourished situation, then we have to be concerned about the growth of the baby, if the baby is going to be getting enough nutrients to grow normally.
Melanie: What about men, Dr. Ziegler? Is there any risk with fertility if a man is obese or underweight?
Dr. Ziegler: Well, mainly with obesity--is what the studies have basically looked at, and studies have shown that obese men have around a 42% chance and are more likely to have a low sperm count than of men of normal weight. There are many obese men that have actually been shown to be sterile because of the weight issue. If a man does gain weight, for every 20 pounds a man gains above their ideal body weight, there is a 10% decrease in their fertility. So, even in that situation, we do recommend weight loss for men because it does improve the sperm sample which we have to work with.
Melanie: So, what do you tell couples when they come in to see you if one or both of them happen to be overweight? How do you counsel them? Do you encounter resistance to the weight issue?
Dr. Ziegler: Well, we stress to them that body fat plays a critical role in their reproduction. Again, we stress to them, the type of foods in which they do eat. We also stress to them that exercise is important. The problem that we run into is that patients who come to our office, they’ve been trying to get pregnant for a while and if we forego fertility treatment waiting for them to lose weight, in many cases, we lose those patients. They either stop treatment altogether or they seek treatment from another practice. So, what we try to do is, we say during the time in which we’re doing their workup--usually we have around four weeks to maybe eight weeks until we start treatment--if we can get them on a regime in which they’re able to maybe lose a pound a week, then that’s beneficial because then we have now decreased their body fat. Again, that has also been shown to help us achieve our objective.
Melanie: Then, if they get pregnant, do weight loss efforts then cease? How does that work?
Dr. Ziegler: Yes. At that point in time, since you don’t want to deprive the gestation, or the baby, of nutrients, we would then recommend stop trying to lose weight because at that point of time it’s going to be detrimental to the mother as well as to the infant. For those that are overweight or those who are obese, we don’t encourage a drastic weight gain in pregnancy because, again, that can come with it a lot of medical complications.
Melanie: So, in just the last few minutes, Dr. Ziegler, give your best advice for the risks and the health hazards and the link between weight and fertility and why patients should come to the Reproductive Science Center of New Jersey for their care?
Dr. Ziegler: Well, our practice is looking at the couple as a whole. This is a partnership between us--both the physician and the medical staff--and the couple or the patient. We want this treatment that we provide to be as successful as possible, yet we don’t want to encourage a lot of frustration. We need for patients to understand that it’s not just a sperm and egg issue. There are more variables to take into account. So, when we talk about the full picture, besides talking about ovarian reserve and besides talking about sperm motility and morphology, which is all part of the situation and the things we have to address, we do need to address social habits. Besides weight, there’s smoking, there’s drinking, there’s recreational drug use. We also have to look at where they work also because they could be around chemicals that could be affecting their fertility. So, it’s not as easy as just come to the office, we give you a pill; we’ll do an insemination and things will be fine. It’s, more or less, we have to take a look at the whole picture and weight is a big part of that, especially with women who have an ovulatory dysfunction because they are overweight. We need to address that. It could be a medical condition, such as insulin resistance that’s causing their weight gain that by treating that, besides helping them from a health maintenance standpoint, that also helps improve their ovulation .Sometimes with that that, they don’t even need any fertility treatment. Just adjusting the medication in which they could be on or adding some medications or having them just lose 20% body fat, really does help. So, it’s a way of looking at the whole picture and not just prescribing medication and just jumping right into treatment. Whether or not a patient desires to follow those recommendations, we give them the pros and cons and how it’s going to help them in the short-term as well as in the long-term.
Melanie: Thank you so much, Dr. Ziegler, for such great and so important information. You’re listening to Fertility Talk with RSCNJ. For more information, you can go to FertilityNJ.com. That’s FertilityNJ.com. This is Melanie Cole. Thanks so much for listening.