Wednesday, June 19, 2013
Stripping membranes is performed by the physician inserting his/her finger into the cervix and moving the finger in a circular motion. This will release the body's own prostaglandins, a substance that can initiate labor. Stripping membranes has varying success but really has no risk.
"Notching" of the wave form of the blood flow of your uterine artery may be a sign of poor blood flow to the uterus and placenta and may lead to a small infant or toxemia (properly called preeclampsia).
Rh Immune Globulin (trademark Rhogam) is given to women with Rh negative blood to prevent the possibility of forming antibodies against fetal red blood cells. Before Rhogam, the risk of developing these antibodies was about 14%. Since using Rhogam, this occurs in less than 1% of Rh negative mothers. The Rhogam only stays in the blood for a couple of weeks and is typically given within 72 hours of any pregnancy event (miscarriage, abortion, delivery).
Bandle's Rings are thick, rope-like, muscular bands that run horizontally around the uterus at the isthmus of the uterus. They can cause an obstruction to vaginal birth and/or an indentation on the baby's head from the pressure of the band. These rings are rare.
Intrauterine Growth Restriction (IUGR) is a term to describe a fetus whose weight is below the 10th percentile for gestational age. To further classify IUGR, it is sometimes categorized as symmetric or asymmetric IUGR.
Symmetric IUGR, or a uniformly small fetus, is usually due to factors present early in the pregnancy such as genetic factors, infection or because the parents are small people destined to have a small child.
Asymmetric IUGR is more common. On ultrasound, asymmetric IUGR fetuses have small abdomens compared to their heads. This occurs because fetuses try to conserve oxygen and nutrients for their brain at the expense of fat. The usual reason for asymmetric IUGR is poor functioning of the placenta due to either maternal hypertension, preeclampsia or any condition that might cause constriction of the blood vessels to the placenta.
It is important to be aware of IUGR so that the pregnancy can be monitored closely. If growth of the fetus tails off, induction of labor is sometimes necessary. If not monitored, there is a risk of stillbirth. It is difficult to diagnose IUGR with a single ultrasound because, even in the best hands, there is a 10% error in calculating fetal weight. IUGR often results in a perfectly normal baby who is just small for its age.
Pre-eclampsia (formerly known as toxemia) is found in about 5-7% of pregnancies. It is a combination of the following findings: high blood pressure with a significant loss of protein in the urine and/or swelling of the hands and face (not feet). In severe cases, there can be nervous system (seizures) liver, kidney and blood clotting abnormalities. Despite years of research, the cause or causes are unknown at this time. Pre-eclampsia can become severe with profuse bleeding, rupture of the liver and seizures. These are uncommon today because pre-eclampsia is usually found in the early stages and treated (with delivery of the infant). Once the baby is delivered, the preeclampsia begins to resolve over hours to days. Time of delivery depends on the severity of the disease and the age of the baby. Medicines are given to prevent seizures and may be given to prevent complications of severely elevated blood pressures. It is one of the more common causes for early delivery.
The majority of women who have endometritis (infection of the uterine lining) have no future problems. It isn't a destructive process. Only rarely could a woman have scarring of the lining of the uterus as a result of endometritis. The lining of the uterus always undergoes an infection of sorts after childbirth, but not to the level of endometritis. After delivery, the lining of the uterus is an enlarged, raw, healing surface. The vagina normally has 10-15 different bacteria residing in it at all times. Put these two combinations together and you have a set up for an infection. Normally the body is able to fight off this infection, and this is why a woman's White Blood Count may be elevated even without endometritis. Some of the risk factors for endometritis are prolonged labor, prolonged time from breaking of the bag of waters and delivery, instrumentation (forceps, manual delivery of the placenta), previous vaginal or cervical infection, etc. Despite these risk factors, many women develop endometritis without any obvious risk factors. A sterile environment does little to ensure endometritis will not occur. A woman's body (skin, rectum and vagina) is loaded with bacteria that can cause endometritis.
Placenta previa is a condition of pregnancy where the placenta is covering the opening to the uterus. This is very common in early pregnancy and if there is no history of vaginal bleeding, few precautions need be taken. There is no increased risk of cord accidents with a placenta previa. The biggest risk is bleeding. Most doctors advise their patients with placenta previa not to have sex. The reason is that sex can cause small uterine contractions that would then cause bleeding in a pregnancy with a placenta previa.
Implantation bleeding is not uncommon. I cannot give you a percentage of times it occurs but it is by no means rare. When obstetricians calculate due dates based on menstrual history, they use the first day of the last normal period to account for this type of bleeding.
A molar pregnancy (also called gestational trophoblastic disease) is an abnormal pregnancy where the placental tissue (or trophoblast) grows in an uncontrolled fashion. The most common type is a complete mole where there is no fetal tissue and is caused (we presume) from two sperm fertilizing an egg that is missing its own chromosome.
A D&C will cure this condition about 80% of the time. After the mole is evacuated with the D&C, the woman must have frequent measurements of the pregnancy hormone hCG and avoid becoming pregnant for at least 6 months (and preferably for one year). The hCG level should drop over several weeks. If it does not fall correctly or begins to rise, that means the patient is in the 20% of patients for whom this does not go away without further therapy. In these patients, chemotherapy is needed. Fortunately, the cure rate is about 99% with chemotherapy. The exceptions to this high cure rate are those who have a special pathology of the mole called choriocarcinoma or people who do not follow their physician's instructions carefully and become "lost to follow-up."
Subchorionic bleeding is an ultrasound term for blood underneath one of the layers of the placenta (the chorion). It is in many ways similar to a placental abruption seen later in pregnancy when the placenta shears prematurely from the wall of the uterus. Many women with subchorionic bleeds carry to term without difficulties. Her chances of miscarriage are higher, however. Her OB will probably suggest repeated ultrasounds to see if the bleed is getting larger or smaller.
Amniotic bands are rare thickenings of amnion (or placental membranes) that can cause a variety of birth defects by constricting a fetal part. It is much like a rope being tied around a limb and cutting off the blood supply to that limb. Amniotic bands typically cause the limbs to be amputated during the pregnancy.
There is no way to protect a woman from developing amniotic bands and, until recently, there was no treatment if it were noticed on ultrasound. There has been a report of fetal surgery to release a fetus' entrapped ankle from an amniotic band. This is a very new and experimental treatment, however.
Last Reviewed: May 28, 2002
Arthur T Ollendorff, MD
Associate Professor of Obstetrics and Gynecology
College of Medicine
University of Cincinnati