sMater | Dr Jinwen He | Obesity in Pregnancy

On this episode of sMater, we discuss obesity in pregnancy with Dr Jinwen He, an obstetric medicine fellow at Mater Mothers’ Hospital.

Jin provides advice on treating pregnant patients who are overweight or obese, and explores the increased risks during conception, pregnancy and the post-partum period for women with high BMIs. She also delves into the impacts of bariatric surgery on women who are trying to conceive as well as the risks associated with Ozempic and other weight loss remedies.

Resources: Guideline: Obesity and pregnancy (including post bariatric surgery)

GP Education activity log:

•  Podcast title - sMater: Obesity in Pregnancy
•  Provider - Mater Misericordiae Ltd
•  Date published - December 13, 2024
•  Certificate of completion - click here

To learn more about Mater, visit https://www.mater.org.au/

Transcript

Hello and welcome to this episode of sMater. A podcast by clinicians for clinicians brought to you by Mater, an Australian leader in healthcare for more than a century. My name is Jillian Whiting and we're coming to you from Meanjin the land on which this podcast is being recorded. Hello I'm Maggie Robin, Community GP rural GP obstetrician at Beaudesert Hospital and coordinator of Mater's GP shared care education program.

In this episode we're talking about obesity during pregnancy with Dr Jinwen He. Jin is an obstetric medicine fellow at Mater Mother's hospital. She's joining us to talk about dealing with risks posed by obesity during pregnancy.

We are Mater. We are Mater. We are Mater. This is sMater.

Hello Jin. Welcome to sMater. 

Thank you for having me. Now obesity we know is increasing worldwide and is the leading risk factor associated with disease in Australia. Why does it matter in pregnancy so obesity definitely matters in pregnancy because we're now finding that 50% of our obstetric population are either overweight or obese and obesity increases the risk of all of the pregnancy complications so this includes things like gestational diabetes, hypertension preeclampsia and even increasing the risk of still birth. With every increment in BMI there is an increased risk of needing instrumental delivery, increased risk of shoulder dystocia and also increasing the risk of needing a cesarian section. If you have a cesarian section and you're overweight or obese there's a higher risk of poor wound healing and all of the anesthetic risks are also higher with obesity. There is a higher chance of a failed epidural or spinal anesthetic and a higher chance of you know airway issues if a general anesthetic is required.

What about postnatal risks?
So postnatally we definitely want to be thinking about the risk of venus thromboembolism which is pretty high in both during pregnancy and the six weeks postpartum. 
Obesity does carry extra risks for thrombosis. We also want to be thinking about wound healing especially in ladies who've had an episiotomy or who've had a caesarian section because there's a higher risk of wound dehiscence and in addition to that there's also an increased risk of breastfeeding issues so thinking about consulting the lactation consultant if needed and also a higher rate of postnatal depression so being aware for that.
Jin, what about risks for the baby during the pregnancy and the postnatal period and and long term?
So we definitely do need to think about risks to the baby. For ladies who have a BMI of above 30, we want to be thinking about the higher dose folate supplementation in the 3 months preconception and in the first trimester because the risk of neural tube defects is higher in the babies. We also have an increased risk of large for gestational age babies so the early screening for gestational diabetes is important as well as growth scans for the baby and then in the longer term there is risk of childhood obesity, infant weight gain so the lifestyle for the child is also really important. 

So if a woman comes in to see us at our GP clinic with a high BMI and she says that she wants to start a family, what screening and testing should be a priority at that point?

So I think it's definitely important to talk to the lady before she falls pregnant educating them about the risks of obesity and pregnancy and trying to optimize their lifestyle before they fall pregnant. In terms of screening we should think about screening for underlying diabetes - type 2 diabetes - so with HbA1c and ideally the HbA1c should be less than 6.5% if they have pre-existing diabetes before they should attempt a pregnancy. Those with pre-existing diabetes also need the high dose folate supplementation preconception. They should have screening for renal disease so ELFTs and a urine protein 

because you can have obesity related FSGS
which can lead to kidney disease and in addition screening for symptoms of sleep apnea and considering a sleep study if there are lots of symptoms and treating that before they fall pregnant. We should get the patient to see a dietician and hopefully lose some weight before they embark on their pregnancy journey.

According to the Royal Women's Hospital in Victoria Australia, 52% of Australian women are overweight or obese including 35% of women aged 25 to 35. As a result of the increase in obesity in these reproductive years, the prevalence of obesity in pregnancy is also rising which can increase complications of labor and delivery.
Maternal obesity has been found to slow cervical

dilation and increase the risk of prolonged labor. Obese pregnant women have higher rates of medical interventions around labor and birth including higher rates of induction for prolonged pregnancy and higher rates of cesarian section as a result of failure to progress in labor. So say someone presents to us already pregnant with an elevated BMI and they perhaps have chronic conditions or we know they're at increased risk of chronic conditions, what should be our approach if they're seeing us for the very first time in in early pregnancy?
So when we see the lady in early pregnancy we should still emphasize healthy lifestyle. Refer them to a dietician and you know talk about moderate degree of exercise like 30 minutes a day for 5 days a week. Because healthy lifestyle does reduce the risk of developing gestational diabetes and it's also the cornerstone for managing gestational diabetes. I think we should talk about the appropriate gestational weight gain to expect and we can print the patient out the charts

for gestational weight gain depending on their BMI. So we do not recommend patients to try to lose weight in pregnancy even if they are obese and overweight and but their gestational weight gain if they if their BMI is high should be lower so for normal BMI maybe it's you know 11 to 16 kilos whereas if their BMI is above 30 it would be closer to 5 to 9 kilos gestational weight gain. The other things we should do would be doing their usual antenatal bloods but including checking their renal function, checking a baseline urine PCR and consider screening for nutritional deficiencies especially if they've had bariatric surgery but even if they haven't had bariatric surgery a lot of these patients are higher risk of vitamin D deficiency so that should be screened for and I think we should check their blood pressure. If they have high blood pressure in the first trimester it's probably chronic hypertension. We should think about screening for other causes of chronic hypertension and also putting them on medications to optimize the blood pressure and we should think about their risk for both preeclampsia as well as venus thromboembolism and think about whether they need preventative medications. 
In terms of preeclampsia if they have other risk factors then we should think about aspirin - low dose aspirin 100 to 150 milligram at night daily from 12 weeks gestation - and in terms of the venus thromboembolism risk if they have other additive risk factors then we have to think about do they need an antenatal clexane or postpartum clexane.

Jen these are such critical conversations that need to happen 
between GPs and their patients about their health and contraception and weight management and that all should be happening before pregnancy as you mentioned but it doesn't always go to plan though. It doesn't, but I think this is why the GPs are so important because they see the patients much more frequently than we do in the hospital and when the patient comes in for other things even if it's unrelated to family planning it's always good to opportunistically raise these issues and talk to the ladies about whether they're planning a pregnancy, do they want to talk talk about contraception, it is really really important and I think that's where our GPs have a such a big role to play.

Bariatric surgery rates are also increasing rapidly it's definitely becoming more common in that women of childbearing age. What should we as GPs be talking about with our patients who have had this surgery or are contemplating having this surgery and also thinking about becoming pregnant? 

So I think, let's start with ladies who are contemplating having the surgery because I think the first thing for them to be aware of is that after having the surgery they should not fall pregnant for at least 12 to 18 months until their weight has stabilized and this is because this is a time where it's the highest risk for small for gestational age babies and highest risk of nutritional deficiencies so talking to them about you know a reliable form of contraception that is not an oral contraceptive while they're embarking on that journey. For those ladies who have already had bariatric surgery and their weight has stabilized and it's been over 12 to 18 months post surgery and they're contemplating pregnancy we should think about checking all of their nutritional panel before they fall pregnant and just making sure that they're linked up with ideally a bariatric dietitian and that they are nutritionally replete and I think you know just also screening for whether they have any have any other complications from the bariatric surgery. So for example for the bypass surgery a lot of ladies can have the Late Dumping Syndrome where they feel quite unwell, get quite hypoglycemic after big meals so just screening for whether they've had any issues post bariatric surgery.

Important micronutrients such as iron, calcium, vitamin B12 and folate can be affected by bariatric procedures due to the changes in secretion of hydrochloric acid and reduced surface area for absorption. These micronutrients are essential during pregnancy and severe deficiency can lead to adverse pregnancy outcomes. As Dr Jinwen suggests, a blood test to screen the patients levels prior to conception is vital.
Is there any particular kind of bariatric surgery which is better than the others for women who intend on falling pregnant?
So there's two most commonly performed procedures in Australia and they are the sleeve gastrectomy and Roux-en-Y bypass and

I think the choice is dependent on the patient how much weight they have to lose and their conversation with the surgeons.

So you would probably have more weight loss with Roux-en-Y bypass than sleeve gastrectomy so that would be chosen for people of higher BMI. I think out of the two the gastric bypass is much more likely to cause nutritional deficiencies compared to and also you know higher risk of getting Delayed Dumping Syndrome compared to the gastric sleeve but I think even the sleeve carries risk of nutritional deficiencies. 

Speaking of nutritional deficiencies and you mentioned before doing extra nutritional panels or screening in patients who've had bariatric surgery, is there a particular list that GPs should test for or a place we can access resources that tell us which extra nutrients to test for?

Yeah it's all in a nice table summarized on the Queensland Health Obesity and Pregnancy guidelines and these tests should be done preconception ideally but if you meet the lady first you know when they fall pregnant then to do it in the first, second and third trimesters and to make sure that they are seeing a dietitian.
Most women with obesity already have dietitians I would imagine is that enough? 
I think it's really important for the ladies who are pregnant to see a dietician with expertise in pregnancy and in those who've had previous bariatric surgery to see a dietician with expertise in bariatric surgery patients and this is because especially in those who've had bariatric surgery they could have unusual nutritional deficiencies that we don't see often things like vitamin A deficiency that you know it's quite tricky to replace so they need to see someone with expertise in that field which we have available at the hospital.

Jin you mentioned earlier the dumping syndrome that some patients can have after bariatric surgery does that have implications for oral glucose tolerance testing for screening for gestational diabetes in pregnancy?
Yes definitely so we do not recommend an oral glucose tolerance test in anyone who has had bariatric surgery both gastric sleeve and bypass and this is because a lot of patients after having a 75 gram glucose load will become hypoglycemic and they will feel unwell and they often don't tolerate this test so the alternatives would be doing a first trimester HbA1c as a screening test so if the you know HbA1c is above 5.9% then that's very suggestive of gestational diabetes and they should be linked up to the diabetes service and be given a glucometer in do doing monitoring. If the first trimester HbA1c is normal then they should at 26 to 28 weeks have a fasting glucose if the fasting glucose is borderline or abnormal they should be provided a glucometer to do four times a day glucose monitoring to see if the blood sugars are inconsistently abnormal in the gestational diabetes range.

Why is it so important for GPs to flag previous bariatric surgery on the referral.

It's very important for us to know because patients who are pregnant often present to hospital with symptoms of nausea or abdominal pain which is often put down to their pregnancy but sometimes bariatric surgery complications such as an internal hernia or bowel obstruction can also present with those symptoms so we would be thinking about that if we knew that they had previous bariatric surgery and if they had very serious symptoms then thinking about imaging and calling their bariatric surgeon so that's really important for us to know and also all the other things we discussed before about you know doing the nutritional screening early, GDM monitoring and growth scans for the baby because there is a higher risk of small for gestational age babies in people who have had bariatric surgery.
I personally have found working in general practice that sometimes patients will not voluntarily tell you about bariatric surgery either because they don't regard it as a surgical procedure or they sometimes have a sense of shame around it they want to move on from it they don't want to talk about it. How critical is it that we know about it and that we remember to ask about it?

I think you're entirely right. We definitely need to sometimes specifically ask the question have you ever had bariatric surgery before
because there could be a sense of shame around obesity and there could be weight stigma but it is very important for us medically to know and we should of course approach this conversation very respectfully with the patient. 

What about Ozempic or Semaglutide and the other medications in that family we're seeing more and more people using these for weight loss. What implications do they have for people who are planning a pregnancy?

Yeah so the GLP-1 receptor agonists are excellent. They really help with the management of type 2 diabetes and obesity and of course we're seeing an increased use of these medications so in terms of women who are planning a pregnancy we still have to advise them that at this stage we do not have the data to confirm that these medications are safe to use in pregnancy or in the breastfeeding phase and all of the data we have come from small case series which so far do not show a link between semaglutide and the related medications with congenital malformations but really we need studies of much bigger numbers to confirm their safety so I would suggest if again talking to the patients preconception if they're not planning a pregnancy currently but want to optimize their weight or diabetes and this is a great medication but once they're actively trying to conceive they should stop the medication if they find out that they are pregnant first trimester and they're on this medication they should definitely stop it but if they are on it for say type 2 diabetes and we stop it in the first trimester then we do need to think about do we need to put them on insulin because their blood sugars could go up after stopping this medication. We need more research in this area don't we?
Yes we definitely do yeah.
Jin thank you so much for coming in today and sharing your expertise with us. Before you go though we'd like to introduce you to a little segment we call The Checkup. We want to know more about you as a person and as a medical professional and Maggie has five quick questions for you. Nothing tricky. Are you ready to go. Okay. Jin how would you describe your handwriting?

I think my handwriting is definitely legible so 
I think that's required for clinical documentation. What was your first ever part-time job? My first ever part-time job was at a Chinese restaurant when I was in high school.

That kind of flows onto my question which is tell me about your favorite meal? Dumplings or any kind of dessert.

What do you do to unwind? I like to watch tv, listen to a bit of music.

And then my final question, do you have any pets and if so tell me about them and if you don't what would be your dream pet if you could have one? So we are actually getting a puppy in 3 weeks but I don't have a pet at the moment but he is a mini groodle and he will be 12 weeks when we get him. Have you got a name for him? His name is Rocky.

Rocky gorgeous. Thanks Jin.
Thank you guys.
For our listeners at home or in the car or having a well-deserved break between patients thanks for tuning in. See you next time on sMater.