of Vitamin C May Trigger
Fetal Membrane Break
NEW YORK (Reuters Health) - Women who get little vitamin C both
before and during their pregnancies have an increased risk of
suffering a ruptured membrane and subsequently delivering prematurely,
according to research presented this week at the Society for Maternal-Fetal
Medicine's annual meeting in New Orleans, Louisiana.
``Vitamin C plays a role in the structure of collagen in the
fetal membrane, and when it's not there, it makes the membrane
weaker,'' lead author Dr. Anna Siega-Riz, an assistant professor
of maternal and child health and nutrition at the University of
North Carolina at Chapel Hill, told Reuters Health.
Women with a low vitamin C intake have been found to be more
susceptible to premature rupture of the membrane attached to the
placenta, leading to an increased risk of premature delivery.
To further investigate the relationship between intake of the
vitamin and membrane rupture, the researchers studied 2,247 pregnant
women enrolled in a study funded by the National Institute of
Child Health and Human Development. The women were given a questionnaire
asking them to detail their intake of various foods before their
pregnancy as well as during their second trimester of pregnancy.
The investigators found a strong relationship between a lack
of vitamin C in a woman's diet and a tendency toward rupturing
the placental membrane.
For example, the women who were in the bottom 10th percentile
of vitamin C consumers before pregnancy, meaning they took in
less than 21 milligrams (mg) of vitamin C daily, had twice the
risk of suffering a premature ruptured membrane during their pregnancy.
Similarly, women who were in the bottom 10th percentile of vitamin
C users during their second trimester of pregnancy, consuming
less than 65 mg of vitamin C daily, were at 70% increased risk
of suffering a premature ruptured membrane.
The researchers controlled for other factors that could contribute
to membrane rupture, such as cigarette smoking, age and race.
But other factors the researchers didn't account for could be
responsible for the association seen in the study, Siega-Riz noted.
For example, women with high vitamin C intake tend to be in better
health and have better overall nutritional habits.
``We can't say causality, because you can't base anything on
observational studies,'' she said. ``This is another study that
shows there is a potential for a causal pathway for vitamin C
leading to rupture of membranes, which needs to be verified with
randomized, clinical trials.''
The researchers found that only 28% of the women said they had
taken vitamin C supplements before pregnancy, while 80% reported
taking a multivitamin by the 30th week of pregnancy. The study's
results suggest that starting vitamins after becoming pregnant
is not enough to ward off rupture risk.
``The best advice we can give is for women to take a multivitamin
preconceptually and throughout pregnancy,'' Siega-Riz said. ``You
can't ignore the preconceptual period--women have to be in good
physical well-being when they become pregnant.''
Reference Source 89