blastocyst implants to fallopian tube when it's an ectopic pregnancy.
blastocyst implants to fallopian tube when it's an ectopic pregnancy.
where does the blastocyst implant when it's an ectopic pregnancy?
fallopian tube
tubal pregnancy is when the egg is implanted in the fallopian tubes. hair-like cilia located on the internal surface of the fallopian tubes carry the fertilized egg to the uterus. fallopian cilia are sometimes seen in reduced numbers subsequent to an ectopic pregnancy, leading to a hypothesis that cilia damage in the fallopian tubes is likely to lead to an ectopic pregnancy. women who smoke have a higher chance of an ectopic pregnancy in the fallopian tubes. smoking leads to risk factors of damaging and killing cilia. as cilia degenerate, the amount of time it takes for the fertilized egg to reach the uterus will increase. the fertilized egg, if it doesn't reach the uterus in time, will hatch from the non-adhesive zona pellucida and implant itself inside the fallopian tube, thus causing the ectopic pregnancy.
ectopic pregnancy
where no intrauterine pregnancy is seen on ultrasound, measuring β-human chorionic gonadotropin (β-hcg) levels may aid in the diagnosis. the rationale is that a low β-hcg level may indicate that the pregnancy is intrauterine but yet too small to be visible on ultrasonography. while some physicians consider that the threshold where an intrauterine pregnancy should be visible on transvaginal ultrasound is around 1500 iu/ml of β-hcg, a review in the jama rational clinical examination series showed that there is no single threshold for the β-human chorionic gonadotropin that confirms an ectopic pregnancy. instead, the best test in a pregnant woman is a high resolution transvaginal ultrasound. the presence of an adnexal mass in the absence of an intrauterine pregnancy on transvaginal sonography increases the likelihood of an ectopic pregnancy 100-fold (lr+ 111). when there are no adnexal abnormalities on transvaginal sonography, the likelihood of an ectopic pregnancy decreases (lr- 0.12). an empty uterus with levels higher than 1500 iu/ml may be evidence of an ectopic pregnancy, but may also be consistent with an intrauterine pregnancy which is simply too small to be seen on ultrasound. if the diagnosis is uncertain, it may be necessary to wait a few days and repeat the blood work. this can be done by measuring the β-hcg level approximately 48 hours later and repeating the ultrasound. the serum hcg ratios and logistic regression models appear to be better than absolute single serum hcg level. if the β-hcg falls on repeat examination, this strongly suggests a spontaneous abortion or rupture. the fall in serum hcg over 48 hours may be measured as the hcg ratio, which is calculated as:
ectopic pregnancy