Science You Can Use: Is it a good idea for diabetic moms to express colostrum prenatally? A new study investigates.

For a while I’ve been hearing about a novel way to help moms of diabetics avoid supplementing their newborns with formula:  prenatal colostrum expression.

It seems like a kind of elegant solution to a complicated problem, in ways I’ll explain below.  But there have been lingering questions about whether or not it’s safe, and a study from the U.K. out last week took a look at some of those concerns.

Some background:  Babies of diabetic moms are at higher risk of becoming hypoglycemic in their early hours and days.  If their mothers are Type 1 diabetics, they are also 10 to 20 times more likely to develop Type 1 diabetes than the general population.  There is an association between not breastfeeding (and perhaps in particular with exposure to cow’s milk formula) and the development of diabetes, so exclusive breastfeeding appears to be very important in reducing risk.

But diabetes causes mothers’ mature milk to arrive later, and they are also more likely to have cesarean deliveries, which is another risk factor for a delay in mature milk production.  So the baby of diabetic mother is both at higher risk of being supplemented with formula, and also at higher risk of the complications of it.

In recent years, some providers have begun experimenting with having diabetic moms express and store some colostrum during pregnancy so that it would be available in case supplementation was necessary.  A 2011 Australian study pilot study of a small group of women (43) suggested that this practice is effective at reducing supplementation and supporting exclusive breastfeeding, though more infants of mothers who expressed required nursery care.  The practice of prenatal expression appears to be growing in popularity.

But the authors of last week’s study say that “the acceptability, risks and benefits of this practice have not been evaluated.”  Of particular concern is whether or not expressing colostrum might make women more likely to go into labor too early, since nipple stimulation is a commonly employed means of inducing labor.  And to their credit, the authors of the Australian study made clear that their sample “was not an adequate number to examine safety or efficacy, but this study does provide evidence that it would be feasible and desirable to conduct a randomised controlled trial.”

So, on to last week’s study from the U.K.  It was a two year retrospective cohort study of 94 pregnant women with diabetes (type 1, 2 and gestational diabetes) who gave birth during 2001–2003.  The information was collected through self-administered  questionnaires and by examining maternity records.

Thirty-seven percent of women recalled being advised to express prenatally,
and 17% did.  They were encouraged to begin expression at 36 weeks gestation (do you see one issue coming already?).  The total number of mothers in the intervention group was 16 (see another one?), and the comparison group had 69.  Higher educated women were more likely to express than less educated women.  Otherwise they looked about the same.

The results:  Mean weeks gestation at birth was a full week earlier, roughly 37 weeks vs. 38 weeks (which is rather early either way, don’t you think?).   They were less likely to be induced, and more likely to deliver by cesarean section, though these differences weren’t statistically significant.  They were more likely to breastfeed at birth, but ended up breastfeeding for slightly fewer weeks (18.5 weeks. vs. 19.9 weeks) in total.  33% of the babies in the expression group were admitted to the special care nursery, compared to 12% in the non-expression group.  As far as I can tell, no information was gathered on in-hospital supplementation rates or exclusive breastfeeding on discharge or later postpartum.

So the story for this small group of mothers, compared to their peers, was:  Expression starting at 36 weeks, earlier term birth, breastfeeding initiation, baby admitted to nursery, little difference in breastfeeding duration.  (No information about exclusivity.)

This sounds, on the face of it, like an early term/late preterm pattern, sometimes called the “impostor baby” syndrome because these early babies often look like full term babies but are immature in a variety of ways that negatively affect breastfeeding.  It also looks like the pattern seen in early elective induction, which increases the risk of NICU admission, and breastfeeding difficulty, among others problems.

In short, this doesn’t look so good.

There are many questions to ask here, but I think that the first should be:  What would this look like if moms weren’t expressing until, say 39 weeks, which is the earliest recommended elective induction cut off (something avidly promoted by the March of Dimes)?  Yes, these babies might be bigger (as they’re already at risk of being large because of diabetes), but wouldn’t they be 1) more ready to be born from a labor and birth standpoint and probably would be more likely to be born vaginally, and 2) have significantly better self regulation which would make them less likely to need nursery care and better at breastfeeding, among other things.  Would that change the outcome?

I also wonder why this pattern isn’t seen in tandem breastfeeding (breastfeeding during pregnancy), which the American Academy of Family Physicians supports “if the pregnancy is normal and the mother is healthy.”  Are mothers at higher risk if they have diabetes?

And finally, if prenatal colostrum expression isn’t an option, should diabetic moms get priority for donor milk to avoid supplementation with formula while waiting for their milk to come in?

This study, and the Australian pilot study which preceded it, are raising some important questions about the practice of prenatal expression for women with diabetes, and we can only hope that larger and more controlled studies of will provide better answers soon.

Did you express colostrum prenatally?  Were you able to avoid your baby being supplemented with formula?  Did your baby arrive early?

Image credit: Wikimedia Commons

4 thoughts on “Science You Can Use: Is it a good idea for diabetic moms to express colostrum prenatally? A new study investigates.

  1. One factor that needs to be considered is that, in many (perhaps even most) hospital settings, type 1 diabetic mothers are automatically induced (or given a c-section) at 38 weeks. So any recommendation for expressing at 39 weeks is a moot point for them.

    I don’t have the medical expertise to say how necessary this 38 weeks cut off date is (I’ve seen it challenged in some recommendations). It certainly comes with all the issues you describe (especially since, although they are bigger, babies of diabetic mothers tend to be slightly delayed developmentally). But these babies are also at increased risk of being stillborn compared to other babies–hence the idea of not allowing the pregnancy to go passed 38 weeks.


  2. I am a type 1 diabetic mother of 2 boys. I don’t think I would ever pump before hand but I wish I had aquired donor milk before both births. I will say that the practices of birthing diabetics early is an old dated practice which is no longer needed and therefore I would never reccomend a mother pump at 36weeks. If a diabetic keeps their blood sugars in good control, the birth should be treated like any other birth. My first son was born via csection after an unneeded induction at 39weeks. I was treated as high risk but there were absolutely no signs this was needed. My second son was a vbac. My doctor didn’t treat me as high risk since I had great control of my blood sugars. My second son was born at 38weeks and 2 days although my doctor was fine with me going to 42 weeks. Both boys had blood sugar drops. my first was rushed to the nicu and since he was on an iv, it took 4 days for his blood sugar to level out. My second son was given small amounts of formula through a curved syringe while I breastfed him. He came home with me a day after he was born with no need for more formula. My first son did successfully nurse till he was 20months even though he got primarily formula during the first 2 weeks of life (we dropped all formula 3 days after he came home). My second son is 8 months and we have no end of nursing in sight. Though I strongly dislike formula, I personaly wouldn’t risk having an early birth caused by pumping. I don’t feel bad I gave my second son the small amounts of formula during the first 24hours since his blood sugar was truely low. Oh, and neither of my boys were big, first was 7pounds 9oz and second was 7pounds 11oz.


  3. Tania,
    Thank you for posting this.
    The new article from the UK also has a very small number of mothers who expressed and so the larger randomized controlled trial which is being undertaken in Australia will give us more meaningful information.
    One of the things that concerns most people is the likelihood that nipple stimulation will induce labor so you may like to read this: Oxytocin receptors need to be in the uterus before labor will start – that’s why all the old wives tales to induce labor do not work.
    Most of the studies of nipple stimulation during the 1980s did not show any change in the Bishop Score unless the woman was at term.
    Another thing you mentioned was breastfeeding during pregnancy and this is a very good article on it: Moscone ST & Moore MJ,1993, Breastfeeding during pregnancy. J Hum Lact 9(2):83-8. Abstract:
    The most important thing in any study is for the authors to tell us how long the babies had in uninterrupted skin-to-skin contact where they can thermoregulate and remain euglycaemia. Abstract: while in skin-to-skin babies at term are able to use their brown fat for heat and energy and have ketones and lactate to maintain euglycaemia.
    The other thing that happens is that unless the blood glucose is not done within a few minutes of birth then it will be below normal as it normally falls to a nadir at about 1 hour after birth. This means that to be accurate blood glucose levels need to be done right within a few minutes of birth or 90 minutes after birth.
    As Kim says donor milk would be wonderful but most of the world does not have milk banks.
    Thank you for the opportunity to comment


    1. Sue,

      Thank you so much for taking the time to comment and clear these things up!

      I’m excited to see the results from the randomized controlled trial. This study was so small, and there were some pieces of information left out which would have been good to know.

      One question: I’m curious about expression starting at 36 weeks. Is the idea to start expression at 36 weeks because it takes some time to build up enough colostrum? If nipple stimulation works at term (37 weeks) are babies more likely to be born early term (as found in this study)? As you know, from a breastfeeding point of view many 37 week babies act a lot more like 36 week babies than 40 week babies. In the RCT is expression starting at 36 weeks? Do you have similar problems in Australia with high rates of late preterm/early term births?

      Thanks also for the blood sugar information!



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