Pregnancy
Pregnancy
BIOCHEMICAL PREGNANCY - What is a Biochemical ( or Chemical) Pregnancy?
If a woman is not pregnant and she has a blood pregnancy test, the result would be negative, as there is no pregnancy hormone (beta hcg) circulating in her blood stream. Now assume that she becomes pregnant by whatever means (naturally or following fertility treatment), the same blood pregnancy test would be positive as there is now beta hcg circulating in the blood stream. These levels are initially quite low but as the pregnancy becomes more established, the levels will rise at relatively predictable rates. For example, in a normal pregnancy, levels rise by roughly doubling every 48 – 72 hours. In a multiple pregnancy, the levels usually rise faster than this.
In these early stages of the pregnancy, the woman does not look pregnant. Further, if an ultrasound exam was performed, it would not show any evidence of pregnancy. This period is called the BIOCHEMICAL PHASE because in reality, the only way we know the person is pregnant, is by doing biochemical blood or urine tests. Eventually, the levels of beta hcg would rise to a level (usually > 2000 mIU/ml), where it would be possible to see evidence of the pregnancy on ultrasound. Initially there would not be a fetal heart beat present but eventually the fetal heart will be seen and eventually heard by Doppler. Also, if there is a multiple pregnancy, one would be able to see the number of gestational sacs within the uterus. Later still, the abdomen will start to bulge and the person can easily be seen to be pregnant. The phase of the pregnancy which follows the BIOCHEMICAL PHASE, is referred to as the CLINICAL PHASE and the medical term for this is a CLINICAL PREGNANCY.
Therefore, the BIOCHEMICAL PHASE refers to that stage of pregnancy from the time of conception or implantation, until there is evidence by ultrasound or Doppler testing and ultimately by physical inspection of the mother, that a CLINICAL PREGNANCY is present. If for any reason the pregnancy fails to progress, we say the person had a BIOCHEMICAL PREGNANCY.
Is a Biochemical Pregnancy a real Pregnancy?
A biochemical pregnancy is indeed a real pregnancy. It implies that an embryo has implanted and secretion of pregnancy hormone ( beta hcg) has taken place and was able to be detected in the mother’s blood stream. With extremely rare exceptions, PREGNANCY IS THE ONLY TIME beta hcg is secreted into the blood stream.
What are the medical implications of a Biochemical Pregnancy?
For patients undergoing medical treatments for fertility, biochemical pregnancies have important medical implications. As discussed above, this event means that an egg became fertilized and early implantation took place. Unfortunately, we often do not know where the implantation occurred – e.g. in the uterus or the fallopian tube ( ectopic pregnancy) . For example if a person has a positive pregnancy test, and then after a few positive tests, the levels start to drop, it could mean that the implantation took place in the fallopian tube and then it spontaneously aborted and the person had an early tubal abortion. Other possible reasons for biochemical pregnancies, could be immunological implantation rejection. This becomes especially important if biochemical pregnancies occur repeatedly. It may imply that the mother’s immune system recognized the pregnancy as “foreign tissue” and mounted a Rejection Reaction to the pregnancy, before it was able to become fully established as a clinical pregnancy. This is an extremely complex medical situation and beyond the scope of this piece. Other possible explanations for biochemical pregnancies include uterine fibroids, polyps or adhesions, which may negatively impact on the implantation of the early pregnancy. Also, past pelvic infection can have disruptive effects on early pregnancies and result in a biochemical pregnancy.
One of the reasons biochemical pregnancies are so common in patients undergoing fertility treatments, relates to the fact that these patients are monitored so closely after any fertility interventions. In reality it has been estimated that biochemical pregnancies occur in up to 60+% of all pregnancies in humans. However, most people are not being monitored closely with blood tests. Usually someone would simply experience a delayed or slightly heavier than normal menstrual period. In reality they may have initiated a pregnancy which was not destined to progress. It is quite fortunate that nature has powerful, in-built “clearing mechanisms” to ensure that not every pregnancy will continue, as we understand from research that the majority of these pregnancies are chromosomally abnormal.
In a sense, a biochemical pregnancy is frequently a retrospective diagnosis. For example, if a person conceives following fertility treatment and we perform a blood test and it is positive, we do not know at that time that the person is going to have a biochemical pregnancy. All we know at that time is that she is in the biochemical phase of what we hope will progress and ultimately become a clinical pregnancy. If she goes on to lose that pregnancy before it has a chance to progress to a clinical pregnancy, we can say in retrospect that she had a biochemical pregnancy.
Rev 04/12
BLEEDING IN EARLY PREGNANCY
Bleeding in early pregnancy is a relatively common problem. Invariably, it is not normal. However, it certainly does not mean that the pregnancy is lost. In fact, especially in patients who have undergone treatment with ART ( Assisted Reproductive Technology – including IVF, Egg Donation, Gestational Surrogacy or Frozen Embryo Transfer or IUI) some bleeding can occur is upwards of 20% of cases. The amount and color of blood flow is very important. The less bleeding there is the better. The darker the blood, the less ominous. Dark blood means the blood is older, which in turn means the rate of fresh bleeding from the uterus, is slower.
If bleeding starts, it is important to try to get to bed as soon as possible. This serves to take the pressure off the uterus and allows the organs to be in a quiescent state. There should be no heavy lifting and no intercourse or other sexual stimulation. You should remain on all supplemental medications (estrogen, progesterone and so forth) until instructed otherwise by the doctor. If you are taking any anticoagulation medications (e.g. Lovenox, heparin or aspirin), they should be withheld until you have discussed the situation with the doctor. It is likely that the doctor will want to see you for an evaluation on the next business day. If the bleeding occurs during the weekend, you will likely not be seen until the following Monday, unless the bleeding is heavy and/or there is associated pain.
The presence of pain associated with the bleeding is important. It may imply that a miscarriage is inevitable. The thing to be concerned about would be an ectopic pregnancy (a pregnancy which is situated in a location other than the uterus). These definitive diagnoses are usually made with exam and ultrasound in the office. Accordingly, the presence of pain should be discussed with the medical team as soon as possible.
Sometimes, a large partial separation of the pregnancy sac can be noted on the ultrasound. This is called an abruption. The size of the abruption is very important. If you consider the gestational sac to be a sphere (much like an orange), if the blood clot (abruption) covers half of the sphere, this would be called a 50% abruption, a quarter is 25% abruption and so forth. The larger the abruption, the more threatening it is to the survivability of the pregnancy. The risk of this partial separation is that it acts as a “wedge”, separating the pregnancy away from the lining of the uterus -- the life line of the pregnancy. The ability of the pregnancy to survive an abruption depends on the size, rate of progression and the stage of the pregnancy. If you are diagnosed with an abruption, it is critical to try to rest as much as possible. This in fact is the only treatment which has been shown to be beneficial. If the bleeding stops, the abruption will become organized and the expanding pregnancy sac will once again adhere to the walls of the uterus. Therefore, complete survival of the pregnancy is possible, although studies have indicated that there is a slightly higher risk of premature delivery in those cases where there has been a bleed in the early part of the pregnancy. Therefore, it would be important to discuss this with your Obstetrician.
When you do achieve success with your fertility treatment, Dr. Batzofin has some important information to make sure you have a healthy pregnancy!
Some Do’s and Don’t’s for pregnancy
1) Do eat nutritious food and avoid uncooked foods.
2) Avoid all smoking
3) Avoid drinking alcohol. A fetus has almost no ability to metabolize alcohol and therefore should be avoided.
4) Take prenatal vitamins including Iron ( to prevent anemia which is common in pregnancy) and Folic Acid to lower the incidence of neural tube birth defects
5) Exercise in moderation – avoid heavy impact exercises, for example; trampoline jumping. Horseback riding is questionable. Some form of exercise is beneficial unless there is active bleeding.
6) Prenatal care is very important.
7) Sexual relations are fine so long as no bleeding and no ruptured membranes. If bleeding, rest and refraining from sexual intercourse is important until bleeding stops.
8) Be cautious with respect to prescription drugs – make sure the treating doctor is aware that you are pregnant. The early stages of pregnancy – weeks 2 – 10 are critical because of organogenesis taking place and it is important to limit prescription drug ingestion because of teratogenicity. For prescription drugs, benefits of use must always outweigh the risks.
9) Travel in pregnancy should only take place when necessary and ideally only during the second trimester. With travel, especially to remote places, there is a risk of exposure to bacteria, food and water contamination and so forth. Some infections like acute lysteria, can be devastating in pregnancy. In later stages of pregnancy, there is always the risk of preterm labor and delivery and ideally the person should not be far from their treating physician or midwife who is familiar with their case.
10) Preparation for delivery and the immediate post delivery period. Good pre-natal care involves preparation for child birth and the issues of the immediate post delivery period for things like breast feeding, early infant nutrition, care of the neonate etc
Rev 4/12
