Posts Tagged ‘placenta’

When your baby is overdue

Monday, September 30th, 2013

bellyThe average healthy pregnancy is around 40 weeks. Some babies come earlier and others run later. A pregnancy that lasts longer than 42 weeks is called a post-term pregnancy.

Dr. Siobhan Dolan discusses overdue pregnancies in the book Healthy Mom Healthy Baby. Here is an excerpt from the book.

“Although many post-term babies are healthy, some risks do start to increase after 41 to 42 weeks. An overdue pregnancy takes a toll on the placenta, amniotic fluid, and umbilical cord. As the baby grows larger, the chances of stillbirth and delivery injuries go up, and there is a greater likelihood that the baby will experience meconium aspiration (inhaling stool from the amniotic fluid into the lungs) or a condition called dysmaturity syndrome (in which the baby is no longer getting enough nourishment because the placenta is aging and becoming calcified).

“When a baby is overdue, the provider may do some tests to check on the baby’s health. They include:
– Ultrasound exam
– Kick count, which is a count of how many times your baby moves or kicks you during a certain period of time
– Nonstress test, in which a fetal monitor measures your baby’s heart rate for a certain amount of time
– Biophysical profile, which uses a fetal monitor and an ultrasound to score a baby on each of five factors (nonstress test, body movements, breathing movements, muscle tone, and the amount of amniotic fluid)
– Contraction stress test, which compares your baby’s heart rate at rest with the heart rate during contractions induced by a shot of oxytocin or nipple stimulation

“If these tests suggest that your baby is in good condition, you can continue to wait for labor to begin naturally. If they raise concerns, your provider may wish to induce labor or perform a c-section. Providers rarely allow a pregnancy to go beyond 42 weeks.”

What is amniotic band syndrome?

Thursday, January 17th, 2013

Amniotic band syndrome is a well-know condition that can include a variety of different birth defects, usually affecting an arm or leg, fingers or toes. No two cases are alike – some are just a single malformation while others can include many disfiguring complications.

The upper body is involved more often than the legs or toes. (If you’re watching the current season of “The Bachelor” on TV, one of the women on the show is missing the lower part of an arm due to amniotic band syndrome.) Sometimes fingers or the lower portion of an arm are smaller than normal, sometimes they are missing all together, or occasionally some fingers may be webbed together. Sometimes a limb may have a deep groove around it showing where a tight band constricted growth.

In other cases, aside from defects of the arms or legs, a baby may also have facial defects (cleft lip or palate), a neural tube defect of the brain or spine, or have portions of internal organs protruding through a hole in the abdominal or chest wall.

The causes of amniotic band syndrome are yet unknown, but there are two main theories. One is that strands of tissue from the inside of the amniotic sac surrounding the developing baby separate from the lining and form bands that float free and entangle parts of the baby. If they wrap too tightly, they can restrict movement, blood flow and proper development, possibly even amputation. This may be due to random chance or trauma to the abdominal area and placenta during pregnancy.

Another theory holds that the cause stems from within the baby itself and involves insufficient blood flow to specific parts of the body. If an area of the body does not receive enough blood, tissues in that area die which can lead to physical defects. Some researchers believe that genetic factors may be involved in these cases. But whether this is caused from within the developing baby or from outside influences, occurrence is random and the chance of having another child with amniotic band syndrome is extremely low.

Treatment really depends on the severity of the defects. Surgery may be recommended to repair defects such as cleft lip or palate, clubfoot, or abdominal wall defects, etc. Sometimes physical or occupational therapies are needed to ensure the child has the best range of motion and use of the affected limb as possible.

What is placenta previa?

Thursday, October 11th, 2012

During pregnancy, the placenta attaches to the wall of the uterus and supplies the baby with food and oxygen through the umbilical cord. Placenta previa is a condition in which the placenta lies very low in the uterus and covers all or part of the cervix. (The cervix is the opening to the uterus that sits at the top of the vagina.)

Placenta previa happens in about 1 in 200 pregnancies. If you have placenta previa early in pregnancy, it usually isn’t a problem. It will be monitored, however, because it can cause serious bleeding and other complications later in pregnancy.

Normally, the placenta grows into the upper part of the uterus wall, away from the cervix. It stays there until your baby is born. During the last stage of labor, the placenta separates from the wall, and your contractions help push it into the vagina (birth canal). This is also called the afterbirth.

During labor, your baby passes through the cervix into the birth canal. If you have placenta previa, when the cervix begins to efface (thin out) and dilate (open up) for labor, blood vessels connecting the placenta to the uterus may tear. This can cause severe bleeding during labor and birth, putting you and your baby in danger.

The most common symptom of placenta previa is painless bleeding from the vagina during the second half of pregnancy. Call your health care provider right away if you have vaginal bleeding anytime during your pregnancy. If the bleeding is severe, go to the hospital.

An ultrasound usually can find placenta previa and pinpoint the placenta’s location. In some cases, your provider may use a transvaginal ultrasound instead.

Even if you don’t have vaginal bleeding, a routine, second trimester ultrasound may show that you have placenta previa. Don’t be too worried if this happens. Placenta previa found in the second trimester fixes itself in most cases.

Treatment depends on how far along you are in your pregnancy, the seriousness of your bleeding and the health of you and your baby. To learn more, read our article on placenta previa.

Single umbilical artery

Friday, August 3rd, 2012

insideAbout 1 percent of singleton and about 5 percent of multiple pregnancies (twins, triplets or more) have an umbilical cord that contains only two blood vessels, instead of the normal three. The cause of this abnormality, called single umbilical artery, is unknown.

The umbilical cord is the life-line that attaches the mother and developing baby. Connecting through the placenta, a normal umbilical cord is made up of three blood vessels. One large vein carries oxygen and nutrient-rich blood to the baby and the two smaller arteries carry blood and waste products back to the placenta. The umbilical cord normally grows to about two feet in length, allowing the baby enough cord to safely move around without causing damage to the cord or the placenta.

In a single umbilical artery, one artery is missing. Studies suggest that babies with single umbilical artery have an increased risk for birth defects, including heart, central nervous system and urinary-tract defects and chromosomal abnormalities. A woman whose baby is diagnosed with single umbilical artery during a routine ultrasound may be offered certain prenatal tests to diagnose or rule out birth defects. These tests may include a detailed ultrasoundamniocentesis (to check for chromosomal abnormalities) and in some cases, echocardiography (a special type of ultrasound to evaluate the fetal heart). The provider also may recommend that the baby have an ultrasound after birth.

The diagnosis of a single umbilical artery does not necessarily mean that the baby will have a birth defect. It does mean, however, that some tests are warranted and that closer attention needs to be paid for the remainder of the pregnancy.

How your baby grows – month 2

Monday, September 5th, 2011

pregnant-couple

Your baby:

By the end of the second month, your baby is about an inch long and still weighs less that 1/3 ounce. Your baby’s major body organs, like the brain, heart and lungs, are forming. The placenta is working. The placenta grows in your uterus and supplies the baby with food and oxygen through the umbilical cord. Your baby’s ears, ankles, wrists, fingers and toes are formed. Eyelids form and grow but are sealed shut.

Your body:

Your breasts may till be sore and are getting bigger. Your nipples and the area around them begin to get dark. You have to go to the bathroom more often because your uterus is growing and pressing on your bladder. You may still have morning sickness. You may feel tired and need to rest more often. Your body is busy making more blood.

The placenta and fetal circulation

Thursday, January 14th, 2010

insideThe placenta is a remarkable organ that connects the mother’s blood supply with that of the developing fetus through the umbilical cord.  It transports oxygen and nutrients to the baby’s blood and returns the baby’s waste to the mom’s blood for disposal through her kidneys.

The placenta, formed from the same cells as the embryo, attaches to the wall of the uterus and to the umbilical cord. Oxygen-rich, nutritious blood travels from Mom to the fetus by the umbilical vein in the umbilical cord.  The umbilical vein delivers the blood to the liver and then much of it travels on to the right side of the heart. Here it mixes with blood of the fetus and is sent on through two special openings, bypassing the nonfunctioning lungs, into the left side of the heart for distribution to the entire body.  After completing the circuit, the blood that has delivered oxygen and nutrients to the fetus now flows via major vessels back to the umbilical cord where the two umbilical cord arteries carry it back to the placenta.

While the placenta allows oxygen and nutrients to pass through it, it also filters out many potentially harmful substances and infections. Near term, the placenta produces hormones that play a role in triggering labor and delivery.  After the baby is born, the placenta’s job is done and the placenta is delivered as the afterbirth.

In some cases the placenta may not develop correctly or function as well as it should. It may be too thin, too thick or have an extra lobe, or the membranes may be improperly attached.  Most of these issues are detected via ultrasound.  Signs of a problem include vaginal bleeding and/or continuous abdominal pain.  If you’re pregnant and have questions about your placenta, ask your doctor about it during an ultrasound.