NEW YORK (Reuters) -- If a pregnant woman is easily forgetful or has difficulty concentrating, British researchers think they know the reason why -- the brain has a tendency to shrink late in pregnancy, suggests a report in New Scientist. And a second report has found that pregnancy may also increase the risk of rejection in women who have had an organ transplant.
It may take up to six months for women to regain the loss in brain size, according to Anita Holdcroft, an anesthetist at the Royal Postgraduate Medical School in London.
Holdcroft and colleagues compared magnetic resonance images (MRI) of 10 healthy women at the end of pregnancy, 6 to 8 weeks after birth, and six months after birth. They observed a "significant" increase in brain size in each case in the period following delivery, according to the article.
The researchers believe the phenomenon may be due to a loss of volume in individual brain cells, rather than in overall number of cells, and it may explain why some women report difficulty concentrating late in pregnancy.
"These are very early findings, but it may be that the two features are linked," Holdcroft said in the article.
The study was a follow-up to one completed last year involving women with pre-eclampsia -- a potentially life-threatening condition in which the face and body swells and blood pressure increases. In that study, researchers assumed that the women's brains would swell in size, but found just the opposite: the tissue was shrinking.
The new research on healthy women suggests that brain shrinkage may be a normal feature of pregnancy.
A second report in ObGyn News found that a 25-year-old woman who underwent a double-lung transplant suffered a severe reaction when she became pregnant 25 months later.
The woman lost 58% of her lung function and was diagnosed with chronic lung rejection. Pregnancy-related nausea and vomiting stopped the woman from taking enough of the medication that prevents rejection.
And the fetus's tissue may have triggered an immune reaction that causes rejection, according to Dr. Scott Donaldson of the University of North Carolina. Ultimately the woman had to undergo a surgical abortion because of the complications.
SOURCE: New Scientist (January 11, 1997); ObGyn News (January 1, 1997)
