All about hCG testing

The American College of Obstetricians and Gynecologists (ACOG) has issued advice on recognizing and avoiding false-positive human chorionic gonadotropin (hCG) test results. In its latest Committee Opinion report, the college acknowledges that "clinically significant false positive hCG test results are rare," citing one study in which five out of 162 women studied had evidence of serum assay interference sufficient to provide misleading results. But the college points out that such results, if unrecognized, can lead to significant and unnecessary clinical intervention.

Reviewing the causes of false-positive hCG results, the ACOG reports that some individuals have circulating factors in their serum that interact with the hCG antibody. The most common of these are heterophilic antibodies—human antibodies that can target animal-derived antigens used in immunoassays. People who have worked as animal laboratory technicians or in veterinary facilities, or who have grown up on farms, are more likely than others to have developed heterophilic antibodies, the college says.

What is a misleading serum test result? The ACOG states: "If results are misleading, they usually are seen with values below 1,000 mIU/mL." To rule out the presence of heterophilic antibodies or other interfering substances, it lists four methods:
1.A urine test: heterophilic antibodies are not present in urine.
2.Rerunning the assay with serial dilutions of serum: lack of linearity confirms assay interference.
3.Preabsorbing serum: some laboratories can pre-absorb serum to remove heterophilic antibodies before the assay is performed.
4.Using another assay: some assays may recognize the aberrant, non-active forms of hCG that some individuals naturally produce. "Repeating the hCG measurement in a different assay system can best detect this problem," says the college.

Concluding, it states: "Caution should be exercised whenever clinical findings and laboratory results are discordant. Although false-positive hCG results are rare, if unrecognized they may lead to unwarranted clinical interventions for conditions such as persistent trophoblastic disease. The physician must judge whether the risks of waiting for confirmation of results outweighs the risks of failing to take immediate action."

Venter Sci-Fi

Craig Venter, the scientist who controversially commercialized the efforts of the Human Genome Project, is claiming to have constructed a synthetic chromosome with his research team, giving rise to an artificial life form. Mr. Venter's institute is expected to make an announcement concerning the development in the coming weeks. If true, the potential applications are simply awe-inspiring. Organisms could be "created" for a plethora of uses. Potential applications include, but are not limited to; medical treatments, environment protection, energy production and, unfortunately, biological weapons of vast sophistication. Speaking about the research Mr. Venter said:

"[this is] a very important philosophical step in the history of our species. We are going from reading our genetic code to the ability to write it. That gives us the hypothetical ability to do things never contemplated before".

The team was able to construct an artificial chromosome of 381 genes and the DNA sequence they have pieced together is based upon the bacterium Mycoplasma genitalium (see picture). The original bacterium had a fifth of its DNA removed and was able to live successfully with the synthetic chromosome in place. The man-made organism, dubbed Mycoplasma laboratorium, still relied upon the intracellular machinery already present to carry out tasks such as replication and metabolism, and in this respect the entity is not an entirely new life form. Though the potential may be phenomenal, at the moment all there is to go on is a scientist's word, and in science facts are the only language of proof. We will be waiting for an official announcement with baited breath.

Assisted Reproductive Techniques (ART)

I am asked by many a patient & at times by friends about ART. Everyone wants to know what exactly is Assisted Conception in layman's terms. Today's blog will attempt to clear the basics of IVF or "test-tube baby" as is known in non-medical language. IVF was the first procedure used to fertilize eggs outside a woman's body. In 1978, the first "test tube baby," was conceived through IVF. Most assisted reproductive technologies (ART) are derived from the IVF procedure.
In an IVF Procedure, the doctor: prescribes hormonal medications to stimulate the ovaries, gathers the eggs with the help of transvaginal ultrasound (see picture), fertilizes the eggs in vitro (outside the body) and transfers the resulting embryos through the cervix into the uterus(see picture).

Follicular Stimulation and Monitoring
At the start of the woman's cycle, the physician prescribes hormones or other medications. These control the timing of the cycle and stimulate the development of multiple follicles, sacs of fluid in the ovary that may contain an egg. Usually, the patient can take these medications at home. After several days, the patient returns to the clinic for a vaginal ultrasound and blood tests that help determine the cycle's progress and the number of follicles. More than one visit may be required.
When the doctor is satisfied with the progress of the cycle and the number of follicles, the patient is instructed to administer an additional injectable medication. This ensures that the eggs will mature on schedule for the retrieval. A minimum number of follicles must develop to make the retrieval worthwhile.

Oocyte (Egg) Retrieval
Egg retrieval is normally performed under anesthesia or intravenous sedation. Guided by vaginal ultrasound monitoring, the doctor inserts a needle through the vagina and into the ovaries. The doctor then draws back the needle to remove the eggs from the follicles. Not all follicles contain eggs. Following the procedure, patients recuperate in a recovery room.

Oocyte (Egg) Retrieval
Patients usually receive intravenous antibiotic therapy during the egg retrieval process. Certain patients will be asked to take additional antibiotics by mouth for 3 to 4 days following retrieval.

Fertilization and Incubation
Once the eggs have been retrieved, an embryologist prepares the eggs and sperm from the partner or a donor. The eggs and sperm are mixed in the laboratory to promote fertilization. In cases of severe male infertility, the embryologist can inject a single sperm directly into an egg - this technique is called Intracytoplasmic Sperm Injection (ICSI). The fertilized eggs, called embryos, are incubated for several days.

Embryo Transfer Procedure
If the embryos develop normally, the embryologist selects the best candidates to transfer into the woman's uterus. Based on the individual situation, the physician and the patient determine the number of embryos to transfer. The physician uses a small catheter to pass the embryos through the cervix and into the uterus. After the transfer, which requires no anesthesia, the patient must rest in a recovery room.

Embryo Transfer
If more good embryos than are needed for the transfer, they can, in some cases, be frozen for use in another treatment cycle.
The physician will prescribe hormonal therapy after the transfer to improve the chances for conception. If one or more of the embryos implant in the uterus, the woman may become pregnant. However, as in the natural reproduction process, there is a risk that pregnancy will not occur.

Variations on the IVF Procedure

Transfer of cryopreserved embryos
This procedure uses embryos that were salvaged from a previous IVF cycle and frozen. The embryos are thawed and transferred into the uterus.

Gamete intrafallopian transfer (GIFT)
Based on IVF, but this procedure does not involve fertilization outside the body. The eggs are mixed with sperm, then surgically placed into the fallopian tubes to allow natural fertilization. GIFT requires anesthesia as well as time in the recovery room.

Intracytoplasmic Sperm Injection (ICSI)
Based on IVF, but the eggs are not merely mixed with sperm in a dish. Instead, a single sperm is directly injected into each egg. ICSI is particularly useful when the man has an extremely low sperm count.

Assisted hatching
A microsurgical procedure in which the embryologist chemically dissolves a small area of the zona pellucida, the shell surrounding the embryo, to facilitate hatching of the embryo and implantation.

Donor Procedures
Any of these procedures, but using sperm, eggs, or embryos from a donor.

Unique "Twin" Conference in Tehran!

A friend sent me these unusual pictures of identical & non-identical twins gathered for a unique Congress celebrating "Twins" in Iran. Have a lazy Sunday & enjoy these pictures. Cheers!

Preimplantation Genetic Diagnosis (PGD)

Although Rotunda does not presently offer any PGD services, I thought it worthwhile to educate our patients & readers about Preimplantation Genetic Diagnosis. Couples with a family history of a genetic disorder and older mothers are relatively more likely to have a baby with genetic birth defects. Preimplantation genetic testing and diagnosis (PGD) can help these parents dramatically improve their odds of giving birth to a healthy child. Embryos that have certain genetic defects develop improperly. Used with in vitro fertilization (IVF), PGD can help us select the best embryos and avoid specific birth defects.
In PGD, a embryologist removes one or two cells from each embryo created in the IVF cycle(see picture). The cells are tested for abnormal genes. Only the embryos that have normal cells are transferred into the woman. Since PGD is not 100% reliable and only tests for specific defects, parents should presently still use other prenatal genetic tests, such as amniocentesis or chorionic villus sampling. PGD is expensive and still considered an experimental procedure by the majority of IVF laboratories.
Presently, only couples with family history of genetic disease and women over age 35 are advised PGD. PGD can detect genetic disorders when the defect is understood. As we learn more about genes and gene defects, PGD will become useful for more patients. PGD can tell whether an embryo will become a boy or girl, and reveal certain genetic conditions, including Cystic fibrosis, Down Syndrome, Duchenne muscular dystrophy, Hemophilia A, Tay-Sachs disease, and Turner Syndrome.
Prior to PGD, many couples with a family history of severe genetic disorder may have decided against having children. PGD dramatically improves the odds of having a baby without the disorder. In some cases, biologists can see whether the embryo has the defect. Some disorders only affect male offspring, so that female embryos may be selected to avoid the condition even if the exact defect isn't understood.
PGD helps prevent the stress and trauma after an abnormal result from an amniocentesis or chorionic villus sampling. These prenatal genetic tests can only be performed after 10-12 weeks into the pregnancy. Patients who use PGD should follow up with one of these tests, but the odds of an abnormal result will be dramatically reduced.
PGD requires the removal of one or two cells from each embryo. The embryo development is slowed slightly, but is otherwise normal. Most embryos are not adversely affected by the procedure. Some embryos may be damaged during the removal. An embryo that the PGD detects as abnormal may be normal in a small percentage of cases. This embryo would not be transferred, even though it could have become a healthy baby. An embryo that the PGD detects as normal may be abnormal similarly. This embryo would be transferred, and would result in a miscarriage or child with birth defects. Because of this risk, other genetic tests, amniocentesis or chorionic villus sampling, should be performed. To decrease the false positive & false negative results, some IVF teams employ a combination of tests using more than one cell biopsies. Since PGD is performed using embryos from an IVF cycle, the patient should be aware of the risks of IVF. There may be too few or no embryos without the defect. The embryos may not implant and develop even if they do not have the defect. If you decide to pursue PGD, you will prepare for an IVF procedure. The woman will take hormones to stimulate the ovaries to produce many eggs. Just as in a normal IVF procedure, the doctor retrieves the mature eggs from the woman. The eggs are fertilized with sperm. After two days, the embryos grow to four to six cells. The biologist forms a small opening in the outer membrane of the embryo, the zona pellucida. This is a similar process to assisted hatching. The technician gently sucks one or two cells out of the embryo through the hole. These cells are then tested for genetic abnormalities. In most cases, all the cells of an embryo will have the identical genetic makeup. Therefore, the tested cells will show the genetics of the remaining, viable embryo. The remaining cells of the embryo are young enough that they will form a complete, normal fetus. The test itself is a standard genetic test. It takes less than 24 hours to perform, so that the patient follows essentially the same schedule as a standard IVF cycle.
Women over 35 are more likely to have eggs with an extra or missing chromosome (aneuploidy). In these cases, the laboratory will examine the cells to count the chromosomes that usually lead to severe birth defects. Each human chromosome has a number, except the X and Y chromosomes that determine gender. The biologist uses a technique called fluorescence in- situ hybridization (FISH) to attach a particular color to each 13, 16, 18, 21, X, and Y chromosome. The biologist counts the spots of each color for each cell (see picture). Normal cells will have two of each color for the numbered chromosomes, as well as two X chromosomes (female cells) or an X and a Y chromosome (male cells). For a family history of a disorder, the laboratory will test for the specific defect. The laboratory must first test cells from the parent who has the disorder or may be a carrier to determine the exact defect. The embryo cells are then tested in a process that uses FISH to see if they contain that exact defect. The test doesn't reveal other genetic defects. After the tests are completed, the best embryos without the defect are transferred into the woman's uterus as in a standard IVF cycle. Follow the recovery procedures for an IVF cycle. If you become pregnant, be sure to follow up the PGD with another prenatal genetic test.

Hydrosalpinx

A leading consequence of infertility in women is fallopian tube blockage. A blockage can be caused by a number of reasons, one of which is fluid retention forming a hydrosalpinx(see picture). A hydrosalpinx is a swollen, sausage-shaped blocked fallopian tube which is often the result of a past tubal infection. When injury causes the end of the fallopian tube to close up, glands within it produce a watery fluid which fills up the tube. Although this watery fluid generally poses no harm to the body, studies conducted on women who had undergone in vitro fertilization have shown that this substance is somewhat toxic to implanted embryos. The women with hydrosalpinges had significantly lower chances for a successful pregnancy as compared with those who had their hydrosalpinges removed prior to implantation.The failure of the in vitro attempts at pregnancy is seen to be rooted on the spillage of the hydrosalpinx fluid into the uterine cavity which houses the implanted embryo. The fluid could dislodge the embryos or kill them thereby resulting in a miscarriage.

In the presence of an infection, the body is often able to naturally fight back and heal itself. However, scar formation may result and cause injured tissues to stick together which is the case in a hydrosalpinx. The injured fimbriae (fingerlike projections at the end of the fallopian tube near the ovary) seal up through adhesions from the scarring brought about by an infection(see picture). Both fallopian tubes are often affected when infection is present. However, a hydrosalpinx is usually seen only in one tube with the other tube left with abnormalities. This is the reason why women with only one hydrosalpinx can also experience infertility.

Hydrosalpinges can be caused by a number of infections and two of the most common are Gonorrhea and Chlamydia both of which are sexually transmitted diseases. Generally speaking, sexually transmitted diseases are the more likely culprits when hydrosalpinges occur. However, they are not the only causes. Any form of injury to the fallopian tube tissues can result to a hydrosalpinx. Some other causes for the formation of a hydrosalpinx are ectopic pregnancies, abortions, miscarriages, abdominal surgeries and endometriosis. These conditions can damage or affect the fallopian tubes and the resulting scar adhesions can likewise seal up the tubes.A hydrosalpinx is often seen to form after pelvic inflammation which can be caused by a number of reasons. Pelvic inflammation, are also often caused by infections and can also result from sexually transmitted diseases. However, other causes exist, including fungal or yeast infections as well as infections from the usage of intrauterine devices. A hydrosalpinx can occur in any woman and the chances of occurrence will increase in the presence of infection-causing microorganisms and/or, injury to the fallopian tubes or to the tissues near them. Unfortunately, it is rarely diagnosed early -if diagnosed at all -because the symptoms are generally mild and some women even experience no symptoms at all. The physical discomforts from the condition are often mistaken to be symptoms of bladder infection or bowel problems.

In mild cases fertility may be restored by opening the tube surgically, otherwise IVF is the treatment of choice. There is some evidence that hydrosalpinx reduces the success rate of IVF and increases the risk of mscarriage. For this reason, some doctors may advise removing, or occluding the hydrosalpinx before the IVF treatment.

Hysterosalpingogram (HSG), Laparoscopy & Laparotomy

Knowing the condition of the fallopian tubes is essential for proper and effective treatment of fallopian tube blockage. This is because, although you may know your tubes are blocked, you won't know which approach to take in unblocking them unless you have an idea of what type of blockage you have. Each treatment procedure addresses a specific problem hence, your doctor or your treatment provider will need at least, a general view of the condition of your tubes and the location of the blockage to be able to prescribe an appropriate action to take to relieve the blockage. There are generally three tests that are employed in determining the condition of the fallopian tubes -Hysterosalpingogram (HSG), Laparotomy and Laparoscopy. We will discuss each test individually in this article.

Hysterosalpingogram(HSG)
A hysterosalpingogram is also known as a hysterogram or an HSG and is a form of x-ray which provides a visual of the inner part of the uterus(see picture). A special liquid (dye) is injected into the cavity of the uterus which is then observed (through an x-ray of the abdominal area) as it travels into the fallopian tubes. The liquid should be seen to spill out of the ends of the fallopian tubes near the ovaries to conclude the absence of any significant blockage. However, if only some of the liquid drips out of the tube or if not a single drop falls out, a blockage automatically becomes a possibility. However, additional tests would be likely recommended as spasms from the procedure can produce a similar restriction or stoppage in the flow of the liquid from the ends of the tubes. In addition, this type of test is not advisable for pregnant women or for those with infection in the pelvic area (procedure can spread infection through the liquid contrast dye used).

Laparotomy
Laparotomy is also known as coeliotomy and is a procedure used either for diagnostic or therapeutic purposes(see picture). This procedure involves surgery, with incision made through the abdominal wall thereby providing access to the abdominal cavity which houses the organ to be checked or treated. This is an ancient procedure & is not recommended for diagnostic purposes in present-times. Diagnostic laparotomy was generally used to find out what may be wrong with a certain structure in the abdominal cavity (e.g. fallopian tubes). This was a significantly invasive form of diagnostic tool and hence women tend to choose the similar yet less invasive procedure, laparoscopy.

Laparoscopy
Laparoscopy is similar to laparotomy in that, it also involves an incision through the abdomen. However, the incision need only be large enough to accommodate a laparoscope, which is a thin telescope-like instrument (laparoscope) to be used in inspecting the organ with the problem. A visual image of the abdominal cavity and the structures in it is projected in a monitor connected to the laparoscope(see picture). The fallopian tube along with any blockages within it can be seen hence the extent, location and general characteristics of the blockage can be determined. This diagnostic tool provides approximately the same quality of diagnosis as laparotomy and is also used in treatment procedures.

Advantages and Disadvantages
All three diagnostic procedures have their benefits as well as disadvantages. A hysterosalpingogram provides minimal information about the condition of the tube and the risks associated with it makes it unavailable to pregnant women and those with pelvic infections. However, it is non-invasive and cheaper as against the two other procedures.

A laparotomy on the other hand provides the clearest access to checking the condition of the tubes but is largely invasive & is not recommended. Laparoscopy is a less invasive procedure and provides the best quality of diagnosis with a magnified image which helps in both diagnosis as well as therapeutics.