CME article 1

Ectopic pregnancy: Overview

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Introduction
The incidence of ectopic pregnancy has markedly increased in the last two decades, andcontinues to remain a diagnostic problem even today. The increasing incidence has been attributed to an increase in pelvic inlammatory diseases, use of IUD's, fallopian tube surgery, and also improved ability to diagnose an ectopic pregnancy. An important point to note is that many women who were infertile because of inflammatory diseases are now successfully acheiving pregnancy by in vitro fertilization; in these patients, there is a high rate of ectopic pregnancies. These patients are also usually under intensemedical surveillance, and suboptimal increases in serum beta-HCG often trigger of referrals for ultrasound examinations to differentiate abortion from ectopic pregnancy.

Clinical Findings
Typically, there is a history of amenorrhoea, perhaps with other symtoms of early pregnancy, followed by a brown vaginal discharge in association with pain. Physical examination is often non-contributary, although uterine enlargement, adnexal tenderness with or without a mass felt, and lower abdominal and pelvic peritonism may be found.

USG findings
Extra uterine :
adnexal mass, either complex or cystic.
Living extra uterine embryo in an unruptured sac extra uterine gestation sac / adnexal or tubal ring cul de sac findings of free fluid, blood, clots, hematosalpinx, or free fluid ion Morrison's pouch which signifies rupture, leaking ectopic.
Intra uterine :
Empty uterus or thickened endometrium central hypoechoic area pseudogestation sac rarely a concurrent intra uterine pregnancy.

Other sites of ectopic pregnancy include interstitial pregnancy, rudimentary horn pregnancy, and abdominal pregnancies.

Colour Doppler:
There is controversy over the value of endovaginal color flow imaging as an aid in thediagnosis of ectopic pregnancy. Some authors minimize the use of Doppler by calling any adnexal mass an ectopic gestation in an appropriate clinical setting, while some believe that perfusion characteristics coulddefine the nature of the mass lesion.
The process of ectopic placentation is morphologically similar whether in the uterus or in the fallopian tube. Blood flow into the inter villous spaces is subject to the same pressure gradient and low-resistance vessels so that high-velocity, low impedance flow should be seen in the tubal mass.
Care however must be taken in the differentiation between placental flow and luteal flow in the ovary since, in 80-85% of ectopics, the pregnancy is on the same side as the corpus luteum.Few ectopic pregnancies may not show any placental flow, these avascular ectopics are probably nonvaible gestations. It is also to be noted that these ectopics may display low serum beta-HCG, indicating the limited activity of the trophoblast; these gestations are especially suitable for medical therapy.

Management
Laparoscopic surgery has revolutionised the management for both intact and ruptured ectopic pregnancies, but now, non-surgical management has been practised for many years, with beta-HCG monitoring and pelvic examinations. Several papers report the use of laparoscopic guided injection of drugs directly into the fallopian tube or gestation sac, including methotrexate and hyperosmolar glucose, and via transvaginal guided ultrasound directly into the gestation sac. Some also believe that color-flow mapping may be useful as an alternative to beta-HCG levels to monitor trophoblastic activity.

Author
Dr. Alpana Joshi, Dept. Of Ultrasound, BYLNair Hospital, Mumbai