In the search for all the factors that may affect in some way the health of the fetus during pregnancy, and the added risks of fetal mortality, researchers from the University of Auckland, in New Zealand, have seen in a study that lying on your back in the third trimester of pregnancy could be more dangerous for the fetus.
The study has been published in the journal The Journal of Physiology and they conclude that the supine position, especially (because they compared it with other positions), modifies the baby's heart rate and activity status to the point that he spends more time in a state known as 1F (the baby barely reacts), as if was adapting to a less favorable situation by spending less oxygen.
To do the study, as we read on ABC, the heart rate of 29 pregnant women and their respective babies was monitored during the third trimester of pregnancy, while changing position to keep each of them for 30 minutes. During these time periods, they recorded the behavior of the babies to assess their status and, consequently, the risks of each posture.
Being on your back adds stress to the baby
After the study, the researchers followed all the women until the time of delivery and all had healthy babies. But that does not mean that they found significant data collected when the woman was lying on her back. In the words of Peter stone, Professor of Fetal Maternal Medicine at the University of Auckland and author of the study:
Our controlled study found that lying on your back can add additional stress to the baby, contributing to the risk of stillbirth in women with underlying disorders.
That is, it is very likely that in healthy women with healthy babies, the mother's posture has no major impact on the health of the fetus, since all women are changing their position throughout the day and even at night. However, in women with risky pregnancies, spending more time lying on their backs could increase the likelihood of fetal death, as the researchers explain.
But ... they only controlled half an hour
That's right, and that's why it is explained conditionally at all times ("could increase", which is not the same as "increases"). The same authors see that the study has limitations in stating the following:
We have only observed the effect of maternal positions for a short period of time while the mother is awake and more research is needed to see the effect of remaining in certain positions during maternal sleep throughout the night.
By this they mean that the next step would be to do studies with more women, evaluating the position they adopt when sleeping (in which they spend more time), to see if it affects the baby's health in any significant way.
Meanwhile, they leave us with another interesting conclusion: the maternal position in which the fetus was less changed was lying on the left side.
