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