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call OTIS Information at (866) 626-6847 or visit us online at:www.OTISpregnancy.org.
Glucophage (metformin) and Pregnancy
The information below will help you determine if metformin use during pregnancy represents an increased fetal risk.
With every pregnancy, all women have a 3 to 5 percent chance to have a baby with a birth defect. The information
contained in this factsheet should not be used as a substitute for the medical care and advice of your health care
provider.
What is metformin?
Does metformin cause birth defects?
Metformin is an oral medication used to
Metformin use during pregnancy has been
lower blood sugar (glucose). It has been used for
evaluated in a number of small studies and has
the treatment of type II diabetes (non-insulin
not been shown to increase the risk of birth
dependent diabetes) and insulin resistance, which
defects. While these studies are reassuring,
is common in polycystic ovarian syndrome
further studies are needed to confirm that
(PCOS). Other names for this medication
metformin does not cause a small increase in the
include Glucophage, Diformin and Glycon.
risk for birth defects.
Metformin can be found in combination with
other medications to lower blood sugar.
If I use metformin throughout pregnancy will it
affect the baby?
I use metformin for the treatment of type II
diabetes. What should I do during pregnancy?
One study reported that treatment of
diabetic women with metformin during
Metformin has been prescribed to some
pregnancy was associated with an increased
women with type II diabetes for use during
chance of developing serious pregnancy
pregnancy. Oral drugs, however, do not control
complications including pre-eclampsia (which
blood sugar levels well enough in some women
includes dangerously high blood pressure) and
during pregnancy. When this occurs, insulin is
stillbirth. More studies are needed to determine
usually the medication of choice. Consult your
if there is a cause-and-effect relationship between
physician about which medication is appropriate
metformin and these outcomes. This same study
for you.
did not find an increased risk of other pregnancy
complications such as pregnancy-induced high
I use metformin to treat PCOS. Should I stop
blood pressure, fetal growth retardation, early
taking the medication before or after I get
placenta detachment or C-section.
pregnant?
Some infants have been reported to have
jaundice because of exposure to metformin
Recent studies suggest that women with
during pregnancy. In addition, infants exposed at
PCOS who are treated with metformin have a
the end of the pregnancy to oral medications that
higher chance of getting pregnant. Other studies
lower blood sugar, such as metformin, may have
have suggested that continuing metformin after
low blood sugar in the newborn period. Some
becoming pregnant may decrease the chance of
authors suggest that this complication may be
first-trimester miscarriage when compared to
avoided by switching to insulin for the 24 hours
women with PCOS who did not take metformin.
prior to a planned delivery. Consult your doctor
Women with PCOS who are planning a
before making any changes to your medications.
pregnancy or who become pregnant should not
One study reported the outcome of
discontinue metformin unless directed to do so
pregnancies after treatment of PCOS with
by a doctor.
metformin during pregnancy. Infants were found
to have normal birth weigh and height. In
References:
addition, at 6 months of age, the infants had
normal weight, height, and social and motor
Briggs GG, Ambrose PJ, Nageotte MP,
development.
Padilla G, Wan S (2005) Excretion of metformin into
The reason a woman has been prescribed
breastmilk and the effect on nursing infants. Obstet
metformin may also pose risks to a pregnancy
Gynecol 105(6):1437-41.
Coetzee EJ, Jackson WP (1980) Pregnancy in
unrelated to this medication.
established non- insulin-dependent diabetics. A five-
and-a-half year study at Groote Schuur Hospital. S
The baby's father uses metformin to control
Afr Med J 58:795-802.
diabetes. Will that harm the baby?
Coetzee EJ, Jackson WP (1984) Oral
hypoglycaemics in the first trimester and fetal
There have been no reproductive studies
outcome. S Afr Med J 65:635-7.
that have looked at the use of metformin in men.
Coetzee EJ, Jackson WP (1986) The
Typically, medications that a father takes are not
management of non-insulin-dependent diabetes
thought to increase the chance of birth defects or
during pregnancy. Diabetes Res Clin Pract 1:281-7.
other problems related to pregnancy.
De Leo V, la Marca A, Ditto A, Morgante G,
Cianci A (1999) Effects of metformin on
gonadotropin-induced ovulation in women with
Is it OK for me to breast feed while I use
polycystic ovary syndrome. Ferl Steril 72:282-5.
metformin?
Glueck CJ, Phillips H, Cameron D, Sieve-
Smith L, Wang P (2001) Continuing metformin
Metformin is transferred into breast milk,
throughout pregnancy in women with polycystic
however, it is found in milk at lower
ovary syndrome appears to safely reduce first-
concentrations than in the mother's blood.
trimester spontaneous abortion: a pilot study. Fertil
Although the infant may receive small amounts
Steril 75:46-52.
of metformin in the milk, the acids in the baby's
Glueck CJ, Wang P, Goldberg N, Sieve-
stomach break down much of the drug before the
Smith L (2002) Pregnancy outcomes among women
infant can absorb it. In two recent studies, none
with polycystic ovary syndrome treated with
of the breastfed infants had any side effects. The
metformin. Hum Reprod 17:2858-2864.
Hale TW, Kristensen JH, Hackett LP, Kohan
infant's pediatrician should be told of any
R, Ilett KF (2002) Transfer of metformin into human
medications the mother takes during breast-
milk. Diabetologia 45(11):1509-14.
feeding.
Hellmuth E, Damm P, Molsted-Pedersen L
(2000) Oral hypoglycaemic agents in 118 diabetic
pregnancies. Diabet Med 17:507-11.
Langer O, Conway D, Berkus M, Xenakis
EM (1999) There is no association between oral
August 2005.
hypoglycemic use and fetal anomalies. Am J Obstet
Copyright by OTIS.
Gynecol 180:S38 (Abstract).
Reproduced by permission.
McCarthy EA, Walker SP, McLachlan K,
Boyle J, Permezel M (2004) Metformin in Obstetric
and Gynecologic Practice: A Review. Obstet Gynecol
Surv 59(2):118-27.
Taylor, AE (2000) Insulin-lowering
medications in polycystic ovary syndrome. Obstet
For information on a related topic see the fact
Gynecol Clin North Am 27:583-595.
sheet for Diabetes and Pregnancy at
Vel_zquez E, Acosta A, Mendoza SG (1997)
http://otispregnancy.org/otis_fact_sheets.asp
Menstrual cyclicity after metformin therapy in
polycystic ovary syndrome. Obstetrics & Gynecology
90:392-395.