The more fetuses a woman is carrying at once, the greater her risk. As the number of fetuses
increase (twins, triplets, quadruplets, etc.), the risk of premature birth x and birth weight y. -
Answers increases, decreases
What are some common complications of multiple pregnancies? - Answers premature birth,
LBW, twin-to-twin transfusion syndrome, gestational hypertension/ preeclampsia, gestational
diabetes
How is multiple gestation related to prematurity? - Answers About 60% of twins, more than 90%
of triplets, and virtually all quadruplets and higher-order multiples are born premature.
The length of pregnancy decreases with each additional baby. On average, most singleton
pregnancies last 39 weeks; for twins, 35 weeks; for triplets, 32 weeks; and for quadruplets, 29
weeks.
How is multiple gestation related to LBW? - Answers More than half of twins and almost all
higher-order multiples are born with low birth weight (LBW).
LBW can result from premature birth and/or poor fetal growth. Both are common in multiple
pregnancies.
How is multiple gestation related to TTTS? - Answers About 10% of identical twins who share a
placenta develop this complication. TTTS occurs when a connection between the two babies'
blood vessels in the placenta causes one baby to get too much blood flow and the other too
little. TTTS can be treated with laser surgery to seal off the connection between the babies'
blood vessels.
How is multiple gestation related to gestational hypertension/ preeclampsia? - Answers Women
expecting twins are more than twice as likely as women with a singleton pregnancy to develop
this complication, characterized by high blood pressure, protein in the urine, and generalized
edema. Severe cases can be dangerous for mother and baby. In some cases, the baby must be
delivered early to prevent serious complications.
How is multiple gestation related to gestational diabetes? - Answers Women carrying multiples
are at increased risk of this pregnancy-related form of diabetes. This condition can cause the
baby to grow especially large, increasing the risk of injuries to mother and baby during vaginal
birth. Babies born to women with gestational diabetes also may have breathing and other
problems during the newborn period.
There are two types of twins: x and y. - Answers identical, fraternal
, What are monozygotic twins? - Answers Identical: One egg is fertilized and splits to form two
embryos. The fetuses share the same genetic material. When the split occurs will determines if
the twins will share a placenta, with either one or two amnions, or if they each develop their own
placenta. In general, the later the split occurs, the more likely that the twins will share one
placenta.
What are dizygotic twins? - Answers Fraternal: Two separate eggs are fertilized by two separate
sperm to form two separate embryos. Fraternal twins are more common because each baby
develops from a separate egg and sperm. Since each has a different egg and a different sperm,
it is like siblings being born at the same time.
What are characteristics of monochorionic diamniotic twins? (5) - Answers -Fetuses share a
single placenta.
-They are always identical twins.
-They have a higher risk for complications because two fetuses have to grow on a single
placenta.
-The placenta is not always equally divided between the fetuses.
-Each fetus's blood circulation is connected through blood vessels in the common placenta, and
blood may pass disproportionately from one baby to the other, leading to the twin-to-twin
transfusion syndrome. (TTTS).
What are characteristics of dichorionic diamniotic twins? (2) - Answers -Fetuses each have their
own placenta with its own chorion and amnion.
-Most of these twins are fraternal; only a minority of these twins will be identical.
What function does the ductus arteriosus have in normal circulation? - Answers The ductus
arteriosus is a normal pathway in the fetal circulatory system that allows blood to bypass the
lungs and flow into the descending aorta to ultimately return to the placenta for oxygenation.
How does the flow of blood in the aorta change after birth and when does the ductus arteriosus
close? - Answers After birth, as a result of decreasing pressure in the lungs and increased
pressure in the aorta, the blood flow changes direction and flows from the aorta to the
pulmonary artery (left-to-right shunt). Functional closure of the ductus normally occurs within
the first few hours to several days after birth.
What is an echocardiogram and what does it provide us with? - Answers A non-invasive
procedure that uses high-frequency sound waves to generate a visual picture of the heart. The
examination allows for evaluation of anatomic structures, including valves, chambers, and
vessels, and gives information about the structure and function of the heart, as well as the
direction of blood flow through the heart.