In this rather weird, but interesting study from Italy, 10 mothers of preterm babies (less than 32 weeks or less than 1500 grams) without ultrasound brain injury or severe retinopathy, and 11 mothers of full term babies were shown photos of their own baby or photos of an unknown baby (from one of the other mothers) while they had their head in an MRI magnet. (Montirosso R, et al. Greater brain response to emotional expressions of their own children in mothers of preterm infants: an fMRI study. J Perinatol. 2017). The photos were of their baby’s face while happy, neutral, or crying. Using functional MRI the researchers determined the activation of several different brain areas, at 3 months corrected age.
All the mothers had more activation in several areas when looking at their own baby’s face than when looking at the unknown baby.
When they compared the responses between the groups, the preterm mothers had greater activation in several areas both when looking at their own baby’s face, and also when looking at the unknown baby’s face, than the term mothers, and when viewing their own infant’s face they showed increased activation in an emotion processing area (i.e., inferior frontal gyrus) and areas for social cognition (i.e., supramarginal gyrus) and affiliative behavior (i.e., insula). The mothers were reasonably well matched, and not suffering from postnatal depression or anxiety.
The weeks of stress in an NICU watching their baby and being able to do little to protect them look like they change a mother’s brain function.
Now what about the dads?
Another article (Paules C, et al. Threatened preterm labor is a risk factor for impaired cognitive development in early childhood. Am J Obstet Gynecol. 2017;216(2):157 e1- e7). and a very interesting editorial, compared 3 groups of children at 2 years corrected age. Babies born late preterm and infants who had been born at term, after an episode of preterm labour. And a group born at term, without a history of preterm labour. The groups were fairly small, (22, 23 and 42 respectively). The episode of threatened preterm labour occurred between 25 and 36 weeks gestation, and isn’t described in this paper, in terms of actual gestational age or other complications associated, except that the membranes were not ruptured. Some of the mothers received steroids, and that was different between the late preterm born babies (55%) and the term delivering babies (100%).
The babies born after threatened preterm labour, whether they delivered at term or late preterm had scores on the developmental/cognitive/motor function screening test which were very similar to each other in almost all domains, and also lower in almost all domains than the controls. Overall, the Odds Ratio for what they call “mild delays in development” (more than 1 standard deviation below the mean, which is really in the lower part of the normal distribution), at 2 years was about 2.0, after an episode of preterm labour.
A very interesting editorial confirms that this is probably the first study to have published such outcomes, although previous studies have shown an increase in SGA after threatened preterm labour. In this new study, also, the threatened preterm labour babies born at term weighed 200 grams on average less than the controls despite being born only 1 day earlier. If this finding is true (and in such a small study we should be careful about relying on it too much) then the big question is: why? Why should an episode of threatened preterm labour, which resolves with eventual delivery at term have an effect on cerebral development? Is it an antenatal influence of perhaps increased intra-amniotic inflammation? Does such an episode affect the home environment? Is it related to the somewhat higher educational level of the control mothers? (Although this was included in the logistic regression model, the differences are quite large, 30% of term delivering babies after preterm labour only had primary education, compared to 14% of controls).
If this finding is confirmed it might lead the way to further research studying the mechanisms, and help us get a handle on the impacts of preterm birth after preterm labour also.