What is an ectopic pregnancy?
An ectopic pregnancy is one which develops outside the uterus. Most ectopic pregnancies are found in the fallopian tube and these are called tubal pregnancies. However, they can also occur at other pelvic sites [although these are rare and hence mostly ectopic pregnancies are referred to as tubal pregnancies], and these include: the ovary; the abdomen; and the cervix.
Normally the sperm fertilizes the ovum at the end of the fallopian tube. The fertilized ovum now a pregnancy travels back to the uterus over about 5-7 days and embeds itself in the wall of the uterus to grow into a normal healthy pregnancy.
If the embryo gets ‘stuck’ in the tube and starts to grow there it forms a tubal ectopic pregnancy.
What are the causes of an ectopic pregnancy?
- Infection-which if severe blocks the tube and causes infertility. However a milder infection often narrows the tube and prevents free passage of the embryo back to the uterus. This may even be a ‘subclinical’ infection where the woman would not even know that she had an infection.
- Tubal surgeries may cause these blocks too
- Family planning operations if they fail more often lead to tubal pregnancies. These failures are not usually a ‘fault’ of the surgeon but because the human body tries to make a new path for the sperms.
- Infections following IUCD [Copper T] insertion
- Previous tubal pregnancies also predispose the patient to an increased risk of a repeat ectopic
- Infertility also predisposes to a higher risk of tubal pregnances
What are the symptoms of an ectopic pregnancy?
Initially an ectopic pregnancy may appear just as a normal pregnancy – with
- A missed menstrual period and symptoms such as sore breasts and nausea.
- Abnormal vaginal bleeding which may occur at the time of, a little later than, the expected period. Often, this bleeding is mistaken for a period. The absence of abnormal vaginal bleeding however does not rule out a tubal pregnancy.
- Pain on the side of the ectopic occurs commonly and may be associated with a feeling of light-headedness.
- If the tube ruptures [bursts], this usually results in severe abdominal pain, fainting and shock.
Making the diagnosis on clinical examination is difficult, and the only suspicious finding may be pain on internal examination. Your doctor may find tenderness when he moves the cervix and he may or may not find a swelling at the region of the tube.
How is a tubal pregnancy diagnosed?
A tubal pregnancy is not always easy to diagnose and the art is to reach a diagnosis before the tube has burst. Symptoms of the patient and a clinical examination are not reliable and your doctor will need to do the following test
- Ultrasound. If the ectopic is large or ruptured this alone may be enough to make a diagnosis. However in early unruptured ectopics this has to be co related with a serum HCG
- Serum HCG. Human Chorionic Gonadotrophin [HCG] is a hormone which is produced by the pregnancy. Correlating the levels of this in your blood with an USG gives a better picture. Often repeated tests need to be done to see whether the level is rising or dropping.
- Combining USG and HCG-A positive HCG level confirms that the patient is pregnant, but does not provide information about the site of the pregnancy. A vaginal ultrasound allows the doctor to locate the gestational sac of the early pregnancy. Occasionally, the sac may be seen outside the uterus, making a positive diagnosis of ectopic on sonography. Often, however, the sac cannot be seen clearly in ectopic pregnancies, especially if it is in an early stage. Then, both the scan and HCG levels need to be studied. In a normal intrauterine pregnancy, the doctor should be able to see a gestational sac in the uterine cavity on vaginal ultrasound, if the HCG level is more than 2000 mIU/ml (this is called the discriminatory zone). However, if the level is more than 2000 mIU/ml and the doctor cannot see a gestational sac; this means that the diagnosis is an ectopic pregnancy.
- Serum Progesterone-Another blood test which can be helpful is a serum progesterone level, which is low (less than 15 ng/ml) in patients with ectopic pregnancies, as compared to normal pregnancies.
- D&C-Sometimes, differentiating between an ectopic pregnancy and an early miscarriage can be difficult. In these cases, if a curettage shows that there is no pregnancy tissue in the uterus (as tested by histopathology [biopsy] examination) then an ectopic is suspected. The diagnosis can be confirmed by laparoscopy, if needed, which shows that the pregnancy is in the tubes, where it appears as a dark bluish bulge.
The major benefit of early diagnosis is that with early treatment it is possible to save the tube, thus preserving fertility and increasing the chances of a normal pregnancy in the future.
Treatment of an ectopic pregnancy
How is an ectopic pregnancy treated?
An ectopic pregnancy could be treated with a variety of methods depending on
- how early it is diagnosed
- whether it has ruptured or not
- where it is located
- how large it is
The biggest risk of an ectopic pregnancy is that as it grows it may rupture and that is disastrous and life threatening. It used to be one of the common OBGYN emergencies but a ruptured ectopic is less often seen nowadays as it is often diagnosed in the earlier stages itself.
If the ectopic is very early and the HCG levels low, one can choose to simply wait and watch. Often, the HCG levels will fall, meaning that the pregnancy is being reabsorbed by the body on its own and no treatment is needed. You would however need to keep a watch on the patient maybe on a daily basis and follow up the blood HCG levels every 48 hours till it falls to a level below 10.
This involves the use of the anti-cancer drug, methotrexate, which acts on the rapidly dividing cells of the tubal pregnancy and kills them, thus preventing the pregnancy from growing further. After giving an intramuscular injection of methotrexate, the beta HCG levels need to be monitored regularly, to ensure they are falling, till they decline to zero. This confirms that the pregnancy has been successfully destroyed.
Surgical treatment could be carried out by both the laparoscopic [keyhole surgery] route or the traditional open surgery. Whatever the route the two most common surgical treatments are
- Salpingostomy-the tube is cut open and the pregnancy tissue removed. The tube is thereby saved and helps for further fertility. This is not usually done if the tube looks badly damaged or has already ruptured
- Salpingectomy-where the entire fallopian tube is removed. This will not hamper fertility if the other tube is normal and functional.
The current “gold standard” for the treatment of an ectopic pregnancy [even a ruptured one - unless the patient has had a very large amount of internal bleeding], is laparoscopic surgery. Open [conventional] surgery should only very rarely be required for ectopic pregnancies in the modern day.