When a Pregnancy isn't in the Uterus
Scary, painful, and just plain dangerous....that's how an ectopic, or tubal pregnancy can be described. And unfortunately, I can add "common" to those descriptors since ectopic pregnancies can complicate 1 in every 40-100 pregnancies overall. When a pregnancy fails to properly implant inside the uterine cavity, it is considered to be ectopic. The places where a gestational sac can grow range from the fallopian tube (most common) to the ovary or cervix (relatively uncommon). Figuring out where it is when it is clearly not in the uterus is the challenge for the health care provider.
One of the earliest indicators that a pregnancy is not progressing normally is bleeding from the uterus/cervix. Once a woman misses her menses and has a positive pregnancy test, she should be on the alert for any bleeding because even a small amount is really not normal. Most of the time, spotting in the face of a positive pregnancy test is harmless, but unless it is appropriately investigated, how would you know for sure?
In addition to spotting or bleeding, pain (usually located on one side or the other) is a classic symptom of ectopic gestation. The pain can stem from bleeding from the site of implantation or from the abnormal expansion of an otherwise narrow fallopian tube. Sometimes, there is literally zero pain to give the doctor clues as to whether or not there is an ectopic, but most women will feel something that they would describe as painful or crampy.
One of the ways to detect the pregnancy implantation locale is the use of vaginal probe ultrasound examination. This device, depending upon the model, has enough high resolution imaging that even a 4 week gestational sac can be seen within the uterus. This test is often used in conjunction with a blood test for the level of pregnancy hormone, HCG. Human chorionic gonadotropin has a fairly predictable rise in the very earliest weeks of pregnancy. The rise is usually on the order of double every other day. Once the level reaches 1200-1500, most practitioners of pelvic ultrasound can "see" the gestational sac in the uterine cavity if indeed it resides there.
If no sac is visible at the appropriate time, the patient may require additional blood testing and imaging studies to find the ectopic gestation. Surgery, while necessary and life-saving in some cases, is not always the treatment of choice. A medication known as methotrexate (also used in chemotherapy for certain cancers) is commonly employed to destroy an abnormally implanted pregnancy before it grows to the point of bursting open inside the abdomen. The drug acts to block folic acid and effectively arrest the progression of growth.
Some known risks for a pregnancy to implant inside a fallopian tube include previous tubal pregnancy, previous tubal infection (PID) such as with chlamydia or gonorrhea, or previous tubal surgery including tubal reasnastamosis (putting "tied" fallopian tubes back together). In those cases, the patient is usually specifically told to seek immediate medical attention if/when she becomes pregnant such that the location of the pregnancy can be determined as early as possible.
If you suspect you might be pregnant, the best plan is to seek confirmation of the pregnancy and it's implantation location at your earliest opportunity by visiting your health care provider. Let someone know if you are having bleeding and/or pain so that all the appropriate tests can be done...it could save your life.