What's this
Definition of Extrauterine Pregnancy
"Extrauterine pregnancy" is the medical term that defines pregnancies in which the implantation of the fertilized oocyte (or embryo) takes place outside the uterus or in an area of the latter unsuitable for embryonic development.
This article is dedicated to the analysis of the causes of ectopic pregnancy, risk factors, therapy and prevention measures.
To review: Epidemiology, Symptoms and Complications of Ectopic Pregnancy
Causes
The picture of the possible causes of ectopic pregnancy is complex and heterogeneous. Sometimes, the abnormal embryo implantation takes place for unknown reasons; at other times, however, it is the result of easily identifiable causal factors (in some of these circumstances, extrauterine pregnancy is even predictable).
Given the complexity and variability of the triggering causes of ectopic pregnancy, experts tend to distinguish the aforementioned causal factors into 3 broad categories:
- The anatomical causes;
- The hormonal causes;
- The embryonic causes.
Before continuing with the analysis of the individual categories, it is necessary to point out that the organism of each woman responds in a different and completely subjective way to external stimuli, therefore it is incorrect to generalize: it is not certain that a possible trigger for a woman causes the same consequences in all other women.
Anatomical Causes of Extrauterine Pregnancy
Among the anatomical causes, salpingitis, diverticula and adhesions that interpose between the tubes stand out. Refining the concept, extrauterine tubal-type pregnancies are caused, in the vast majority of cases, by salpingitis (generic inflammation affecting the salpingi or fallopian tubes): in similar circumstances, the mucosa surrounding the tubes is altered by the inflammatory process, thus the mechanisms that control the passage of the zygote towards the uterus are denied. It has been calculated that about 80% of women subjected to a tubal excision following an ectopic pregnancy suffer from chronic salpingitis: this is an impressive figure, which further confirms the influence of salpingitis on pregnancy.
Furthermore, among the causes of an organic nature are mentioned: uterine fibroids, voluntary interruptions of previous pregnancies, surgical interventions at the level of the endopelvic organs and on the tubes in particular, pelvic inflammatory disease, use of the contraceptive coil (it could generate infections, when inserted incorrectly) . Severe bacterial infections in the pelvic area are a dangerous risk factor for the manifestation of an extra-uterine pregnancy, since they could alter the functionality of the tubes and their morphological structure.
The extrauterine pregnancies leave an indelible imprint on the woman, since they seem to constitute a further causal element for subsequent pregnancies.
Hormonal Causes of Extrauterine Pregnancy
The alteration of the hormonal structure seems to constitute another cause responsible for the anomalous nesting of the embryo in extrauterine sites: the progestin and estrogenic overabundance (hyperestrogenism) could alter both the physiological times of migration of the oocyte in the direction of the uterus, and the timing of fertilization of the embryo.
In fact, the excess of estrogen increases the tone of the smooth muscle of the isthmus (the first tract of the tubes, near the ampulla of the uterus); in turn, the zygote tends to stay too long in the ampoule.
Conversely, the excess of progesterone is the main cause of the loss of muscle tone, consequently the fertilized egg remains in the tubes for too long.
A similar hormonal alteration represents the major risk factor for ectopic pregnancy, especially for women who have undergone emergency contraception, taking very high doses of estrogen.It seems that the excess of estrogens and progestogens represents a possible cause of extrauterine pregnancy, even for women who complain of severe luteal phase deficiency, who have considerable and repeated delays in ovulation and who have taken the minipill for a long time. from Gynecological surgery by Mario Vignali].
Hormonal Causes of Extrauterine Pregnancy
The search for possible causes of an embryonic nature, which cause extrauterine pregnancy, seems to be more complex and less defined than the previous ones. Women who undergo assisted fertilization represent the category most at risk: in fact, in these cases, it can happen both a "late ovulation" of the postmature oocyte, and a "premature ovulation of the" oocyte (not yet fully formed); consequently the embryo could implant itself in extra uterine sites, failing to reach the uterus. [adapted from Gynecological surgery, by Mario Vignali].
Therefore the damage of the embryo and the alterations (premature or late) of the nesting of the ovum could represent the embryonic causes that lay the foundations for an ectopic pregnancy.
Risk factors
According to what experts report and on the basis of what has emerged from some researches, they play the role of risk factors for ectopic pregnancy:
- A past history of ectopic pregnancy. Women returning from an ectopic pregnancy tend to run into the same problem at a later gestation.
- A previous sexually transmitted disease. Sexually transmitted diseases such as gonorrhea or chlamydia cause inflammation of some structures of the female genital system (including the fallopian tubes), which is an established risk factor for ectopic pregnancy.
- The use of fertility treatments. Some scientific research has found that women who became pregnant after fertility treatment were more prone to the phenomenon of ectopic pregnancy.
- Tubal surgery. Statistics show that abnormal embryo nesting is easier in women undergoing surgery to the fallopian tubes.
- The use of the intrauterine coil (or intrauterine device). The intrauterine spiral is a generally effective method of contraception; however, in those cases in which it has failed in its intent, experts have noted a marked tendency, on the part of the women concerned, to develop an ectopic pregnancy.
- Cigarette smoke. Scientific studies have shown that women who smoke are more prone to ectopic pregnancy.
In addition, women who, after ligation of the fallopian tubes, have decided that they want to attempt pregnancy are more at risk of ectopic pregnancy.
Therapy
What are the therapeutic approaches that can be adopted in the presence of extrauterine pregnancy
The therapies currently available to treat an ectopic pregnancy concern surgical treatment and drug therapy: as already analyzed, however, the therapeutic strategies, although advanced, could have a significant impact on future pregnancies.
Pharmacological Therapy of Extrauterine Pregnancy
Pharmacological therapy consists of injecting methotrexate or potassium chloride intramniotic, an avant-garde, albeit very invasive, therapeutic strategy. The intramuscular inoculation of the drug is certainly less invasive than the previous one and in any case effective.Pharmacological therapy with methotrexate is very efficient in removing the extrauterine embryo: moreover, this therapy appears to be effective in preserving the good characteristics of the uterus for any future pregnancies.
Pharmacological therapy generally represents the choice of excellence for those extrauterine pregnancies in which the woman has a past of surgical interventions, is suffering from pelvic adhesions or shows contraindications to general anesthesia.
Surgical Therapy of Extrauterine Pregnancy
Surgical therapy, of course, is more invasive for the patient and is generally recommended after having ascertained the ineffectiveness of any pharmacological treatment. The surgeon must operate paying close attention to preserving the integrity of the tube, should the woman wish to have a " other pregnancy. In the most serious cases of ectopic pregnancy, the surgeon must proceed by removing the uterus: the most serious form is represented by cervical ectopic pregnancy.
Prevention
What are the Prevention Measures for Extrauterine Pregnancy?
Currently, there are no measures of absolute prevention of the phenomenon of ectopic pregnancy. By adopting certain behaviors, however, women wishing to have children in the future can still satisfactorily control the risk of an abnormal embryo implantation.
Among the behaviors in question, the following deserve a mention:
- Limit the number of sexual partners, in order to remove the hypothesis of falling ill with a sexually transmitted disease;
- Using condoms during unsafe sexual intercourse not yet aimed at procreation, in order to reduce the possibility of contracting a sexually transmitted disease or pelvic inflammatory disease.
- Not smoking. Cigarette smoking is not only a contributing factor in ectopic pregnancy, it is also a factor that hinders conception.
.jpg)
