22 Weeks Pregnant - ultrasounds in pregnancy: good or bad?
Weekly pregnancy updates from a childbirth educator, doula and mum to 2 little girls. Come and join me on my journey as I share how I’m feeling, how baby is developing, what I’m doing to prepare, and some favourite resources!
So! We had our anatomy/morphology ultrasound, and if you were following my Instagram stories you’ll know that our baby is... a boy!! I am so thrilled that my girls will have a brother, and for sure excited that he has such amazing big sisters 🥰
This feels like a good opportunity to chat a bit about ultrasounds in pregnancy. We’re so used to them, they’re completely the norm, but have you ever actually thought about the pros and cons?
The norm in Australia
Typically in Australia, the standard is one ultrasound around 12-14 weeks of pregnancy and one around 20-22 weeks, plus an optional extra around 8 weeks for dating/to confirm pregnancy. In a high-risk pregnancy, or even in a low-risk pregnancy if there seems to be a need, further ultrasounds will be recommended. Ultrasound is an amazing medical tool, but the problem is it hasn’t been researched in depth for use in pregnancy. We can say that there are no known long-term negative effects on baby, but if we’re being honest, it really hasn’t been around long enough to prove there aren’t any long-term negative effects either!
WHO research and recommendations
Research done by the World Health Organisation in 2009 says: “In the last four decades, ultrasound has become a valuable and increasingly popular tool in obstetrics. Since ultrasound is a form of energy, it has the potential to produce biological effects that can constitute a risk for health. Animal studies suggest that ultrasound may produce adverse effects in the neurological, immunological, hematological, developmental and genetic status of the exposed fetus. Thus there is a basis for concern about the safety of humans exposed to diagnostic ultrasound during fetal life. Because no clinically evident immediate adverse effects have been reported in humans, most health professionals and patients consider diagnostic ultrasound in pregnancy to be a safe procedure. However, as with any diagnostic test, there may be some risk.” (https://obgyn.onlinelibrary.wiley.com/doi/10.1002/uog.6328)
The World Health Organisation issued the following recommendation in 2022: “One ultrasound scan before 24 weeks of gestation is recommended for pregnant women to estimate gestational age, improve detection of fetal anomalies and multiple pregnancies, reduce induction of labour for post-term pregnancy, and improve a woman’s pregnancy experience.” (https://iris.who.int/server/api/core/bitstreams/6549aec3-998c-4410-9a5c-ef544a2049c7/content)
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As with so many other things, it comes down to weighing up the benefits and the risks. Are there risks to ultrasounds? Maybe. Are there benefits? There can be, in terms of directing care of mother and baby and improving outcomes in the case of anomalies. Clearly we could say that in a low-risk pregnancy ultrasound doesn’t provide any material benefit. So why do it if there are potentially unknown risks? But the fact is that when there are anomalies which would benefit from additional care throughout pregnancy (e.g. placenta previa) or indicate the possibility of immediate need for intervention after birth (e.g. baby with heart issues), they are often detected only through ultrasound. So once again it becomes a very real situation where as parents we need to weigh up the risks and benefits and make the decision we feel is best for us and our baby.
My experience with ultrasounds
We do know that the guidelines are for a relatively low level of energy to be used in pregnancy ultrasounds, to minimise any potential negative effects. We just still don’t know if that low is low enough! I remember my midwife with my first baby mentioning that while it was completely up to us to decide when we wanted a scan, she would recommend waiting till at least 12 weeks. Her reasoning was that whatever else it is or isn’t, ultrasound is certainly an intervention, and we don’t want to risk interrupting the delicate balance of growth and development in that first trimester earlier than we have to! I have always remembered this, and have never opted for an 8 week scan since (personal preference!). I’ve just had one around 12 weeks and one around 20-22 weeks. But I have to say, lying on the bed for the anatomy ultrasound the other day for a full hour while the sonographer looked at and measured EVERYTHING, I couldn’t help wondering... is this really all necessary to get a good idea of baby’s health? I mean, of course it makes sense to check that the heart is well-developed, the spine is looking good, head and abdomen are all measuring in proportion to each other and around the expected gestation... but is it essential to check how many fingers and toes there are? Yes, I loved seeing them, they’re so cute! But if my baby was born with all organs functioning perfectly but with one less toe, is that really something I need a scan to tell me before baby arrives? I just feel that it might be more helpful to focus on essentials and reduce the length of the scan as much as possible, to avoid exposing baby to that ultrasound energy for any longer than is necessary.
I was chatting with my midwife after the scan and brought this up. She said that most ultrasound providers offer all or nothing when it comes to the morphology scan. They’re just too worried about the possibility of litigation if something gets missed in the scan…
Plans for the future?
If we have another baby in the future I’m honestly in two minds as to what my decisions will be around ultrasounds. I’m potentially inclined to skip the first trimester ultrasound and just wait for the 20ish week scan (but it is so loooong?!). Though I do LOVE getting to see my baby at that first scan too, and I’m always dying to know whether it’s just one baby or twins! Oh man, such hard decisions!!
Growth scans are notoriously inaccurate!
Now... don’t get me started on growth scans!! Scans in third trimester (“just to check the baby’s growth”) are notorious for measuring inaccurately. The idea is that we’ll scan to check baby’s size, and if it looks like baby is big, we’ll recommend an early induction to avoid baby getting too big to be born safely. Firstly, “too big to be born safely” is a very, very subjective concept. My view is that your body is the right size to birth your baby. Yes, with a big baby there may be a higher risk of shoulder dystocia, but if the mother is allowed to labour actively and change positions as she feels the need, (rather than being kept on her back on a bed!!) the likelihood of baby getting stuck is extremely low. There are some very simple techniques for resolving shoulder dystocia. You might prefer to check that your provider is familiar with these techniques “just in case”, and then actually wait till your baby is ready to be born rather than inducing. Because secondly, studies show that approximately 50% of babies induced early because they were suspected to be “big babies” are actually average size or smaller than average. The crazy thing is that even though these growth scans have a 50% fail rate, they’re still being used as a basis for recommending that babies be born before they’re ready! I am not saying don’t have growth scans. In some higher-risk pregnancies there might be a need to check that baby is growing at a good consistent rate. But just be aware of the pitfalls here too!
What symptoms am I feeling?
I’ve had a few more aches and pains some nights lately with sleeping positions. I mentioned way back in week 16 that I’d started using a pillow between my knees and ankles, but that ended up only being a few days and I haven’t needed it since. That was until this week... but even now it seems I need it some nights and not others. Overall I’m still sleeping quite well though, thankfully!
I am also super excited that I’m able to eat meat at breakfast again and still feel like a normal person! I actually hadn’t tried it for a good month or more, since the last attempts hadn’t gone well, but this week I gave it a go and it was fine!
How has baby been developing this week?
At approximately 29cm and 480g, baby’s nervous system has matured and the links between brain, spinal cord and nerves are established, enabling them to recognise light, warmth and sound. So cool!!
What am I doing to prepare?
I am loving being into the rhythm of birth prep exercises: the stretches and releases, the breath work, the mental prep. This week I also managed to add in a few walks which will hopefully become very regular now. With all the travelling, things have been a bit hit and miss!
And that’s it for this week! 🌿💛
[Image: our baby at 21 weeks]