An ectopic pregnancy (EP) occurs when the embryo attaches in a place other than the womb. After egg fertilization, the resulting embryo starts a journey through the Fallopian tube toward the uterus. However, due to any of the causes that we will see below, it is unable to make it to the uterus and attaches in another place of the female reproductive system, which leads to ectopic pregnancy and miscarriage.
In 95% of the cases, ectopic pregnancies occur in the Fallopian tubes, and for this reason it is commonly referred to as tubal pregnancy as well. Less common places include the ovary, abdominal cavity, or the cervix. If not treated, this type of pregnancy can lead to serious complications in the woman.
The different sections of this article have been assembled into the following table of contents.
In natural pregnancies, egg fertilization after ovulation takes place in the Fallopian tubes. However, the resulting will have to travel through the tubes and make it to the uterus, which is the right place for implantation and subsequent fetal development. The endometrium or uterine lining has been especially designed for sustaining the gestational sac.
An ectopic pregnancy (EP), also known as extrauterine pregnancy, may occur when the embryo is unable to complete its journey towards the uterus, or it hasn't traveled far enough as to be able to land in the uterus. As a consequence, it attaches to a place other than the uterus. Unfortunately, this fact leads to miscarriage, as embryos cannot grow outside the maternal womb.
Ectopic pregnancies are amongst the most frequent causes of maternal death during the first trimester of pregnancy. The mortality rate is 1.8 deaths per 1,000 ectopic pregnancies.
The different types of ectopic pregnancy are classified based on the place outside the womb where the embryo attaches. Most ectopic pregnancies occur in the tube, though.
The following is a list of the different types of ectopic pregnancy and their names:
- Tubal or ampullary ectopic pregnancy
- The embryo attaches in the Fallopian tube, causing inflammation and blockage.
- Isthmic ectopic pregnancy
- Implantation occurs in the isthmus of uterine tube, the closest segment to the uterus.
- Ovarian ectopic pregnancy
- Embryo implantation occurs in one of the ovaries, and it is sometimes confused for a cyst.
- Cervical ectopic pregnancy
- The embryo attaches to the cervix.
- Abdominal ectopic pregnancy
- The embryo grows outside the womb in the abdomen.
- Intramural or interstitial ectopic pregnancy
- It is a rarest of all types. The embryo attaches to the myometrium (smooth muscle within the uterus).
A heterotopic pregnancy is a "hybrid" type of ectopic pregnancy in which an extrauterine and intrauterine pregnancy occur at the same time.
The cause of this type of pregnancy is due to the presence of a barrier or element that delays the process of embryo implantation after egg fertilization.
There exist a series of risk factors that increase the risk of having an ectopic pregnancy, including:
- Salpingitis: infection in the Fallopian tubes.
- Birth defects of the Fallopian tubes
- Advanced maternal age (>35)
- Previous ectopic pregnancies
- Intrauterine Device (IUD)
- Pelvic Inflammatory Disease (PID)
- Pelvic or abdominal surgery
- Fertility treatments
- Tubal ligation reversal
In some causes, finding out the cause is not possible. In fact, it may be due to hormonal imbalances.
It should be noted that the frequency of ectopic pregnancies has increased in the past 20 years due to, on the one hand, new diagnostic methods, and on the other hand, the presence of new risk factors, such as the use of Assisted Reproductive Technologies (ART).
The incidence rate of ectopic pregnancies is 1 per every 100 pregnancies, that is, 1%.
When embryo implantation occurs in a place other than the endometrial lining, it is likely that no symptoms appear in the first days, or they may resemble those of a normal pregnancy, including fatigue, nausea, or abdominal pain.
However, as the ectopic pregnancy progresses, more serious symptoms will appear and make the woman suspect that something is not going as it should. The main ones are:
- Sharp, intense abdominal pain
- Abnormal vaginal bleeding
- Weakness and/or dizziness or fainting
- Lower back pain
- Shoulder pain
- Rectal pressure
- Pale skin and low blood pressure
These symptoms can become worse in case a ruptured ectopic pregnancy occurs, as it is a life-threatening situation that needs emergency surgery. As the embryo grows, the tube expands until it gets to tear or burst, given that the Fallopian tubes are narrow structures that can only stretch a little. It is a medical emergency that can cause heavy internal bleeding and may cause the woman to die if not treated on time.
In short, seeing a doctor as soon as possible if you suspect that you may be having an ectopic pregnancy is crucial. If treated on time, we can prevent further complications such as needing surgery to remove the Fallopian tube.
There exist two basic methods for detecting an ectopic pregnancy: determining the beta-hCG blood levels, and performing a transvaginal ultrasound.
A quantitative β-hCG blood test is used to determine whether a woman is pregnant based on the weeks of pregnancy. This type of pregnancy test is very common amongst women who have undergone a fertility treatment such as IUI or IVF.
If the result is positive, the pregnancy is confirmed by ultrasound within 2 weeks in order to determine the presence of an embryonic sac.
If no gestational sac were seen by ultrasound with a positive β-hCG blood test result, you may be having an ectopic pregnancy. In such case, the β-hCG blood test would be repeated to confirm the levels of biochemical markers such as progesterone, placental protein 14, CA 125, and creatine kinase (CK), among others.
In ectopic pregnancies, the beta-hCG hormone doesn't increase so rapidly as in normal pregnancies. As a consequence, the levels remain low.
Many ectopic pregnancies, especially the tubal type, go away on their own by just causing an early miscarriage. Nevertheless, when abortion doesn't occur spontaneously, the woman will have no choice but to terminate the pregnancy through surgery or with abortion pills such as Methotrexate.
The treatment of choice will be determined after a series of diagnostic and based on the symptoms described by the patient. Your physician should inform you in detail about the pros and cons of each treatment option.
In cases of ruptured ectopic pregnancies and shock, more challenging treatments may be required, such as a blood transfusion or even a salpingectomy in case the tube is severely damaged.
FAQs from users
How do you know if you have an ectopic pregnancy?
A woman with an ectopic pregnancy may have abnormal pregnancy symptoms such as nausea and vomiting with pain, stabbing cramps, weakness, pain the the shoulders, neck or rectum, vaginal bleeding, etc. If this is your case, you should see your doctor immediately. She will perform various tests to confirm whether it is an ectopic pregnancy.
Can an ectopic pregnancy be saved?
Unfortunately, the answer is no. A baby cannot develop properly outside the uterus. It is very dangerous for the woman's health. An ectopic pregnancy can cause the Fallopian tube to burst, which is a life-threatening condition for the woman.
How does bleeding from ectopic pregnancy look like?
Actually, it varies radically between pregnancies because it depends on where the embryo has implanted and the damage done to the area surrounding it. Discharge color can vary from brown to bright red in case heavy bleeding, with or without blood clots, appears.
Suggested for you
A quantitative beta-hCG blood test helps detect ectopic pregnancies, as we have seen above. The following guide to normal beta-hCG levels during pregnancy may help you understand what's considered normal and what's not: What Are Normal hCG Hormone Levels during Pregnancy?
Does an ectopic pregnancy affect future fertility? This is a frequently asked question from women who have gone through an ectopic pregnancy or miscarriage. Check out this for information: Pregnancy After a Miscarriage or Abortion – When to Conceive Again.
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