In a study it is observed that the right ovary ovulates more than the left, all are possible explanation for the cause except:
Ans. c. Right handedness is more common in population (Ref: humrep.oxofordjourna.org/content/12/8/1730.full.pdf)In humans, right ovary ovulates more than the left:It is believed that right sided predominance was either genetically determined or due to differences in vasculature of the ovaries.The anatomical asymmetry between the left and right side are also thought to be the reason.OvulationIn the primate, it is suggested that ovulations occur with equal frequency in the left and right ovary.In the humans, there is some controversy about the frequency of ovulation on either side.It is believed that in normally menstruating women, ovulation was significantly higher in right ovary.It is believed that right sided predominance was either genetically determined or due to differences in vasculature of the ovaries.The anatomical asymmetry between the left and right side are also thought to be the reason.The Left ovarian vein drains to the left renal vein and the right ovarian vein to the IVC.The left renal vein is thought to be under pressure than the right and therefore drain slower. Because the left ovary drain slower, the collapsed follicle (corpus leuteum) takes longer to clean and thereby diminishes the chances that ovulation will occur on that side the following month. No such condition exists on the right side, that's why successive right side ovulation is more common.In this patient the size of adnexal mass is 5 x 5 cm so expectant management cannot be done. But since the patient is hemodynamically stable, laparoscopic surgery will be the management of choice."Ectopic Pregnancy: Laparoscopy is the preferred surgical treatment for ectopic pregnancy unless a woman is hemodynamically unstable. "--Williams Obstetrics 24/e p385Ectopic PregnancyDefinition: Fertilized ovum implanted and developed outside the normal uterine cavity. MC site of ectopic pregnancy: TubalQ (97%)Rarest ectopic pregnancy: Primary abdominalQMC site of ectopic pregnancy in fallopian tube: AmpuIlaQ(Ampulla>lsthmus>lnfundibuluin >Interstitium)Least common site of ectopic pregnancy in fallopian tube: Interstitial partQEtiology:PID: PID is the MC cause of ectopic pregnancyQ. Chlamydia is the MC cause of PIDQIUCD failure: Highest rate with progesteroneQ; Lowest rate with levonorgestrelQPrior tubal damage either from a previous ectopic pregnancy or from tubal surgery to relieve infertility or for sterilization confers the highest risk for ectopic pregnancy.Risk factors for Ectopic PregnancyHigh RiskModerate RiskSlight Risk* Tubal corrective surgery* Tubal sterilization* Previous ectopic pregnancy* Artificial reproductive technology* PID* Infertility* Contraceptive failure* Previous genital infection * Multiple partners* Previous pelvic or abdominal surgery* Smoking* Douching* Intercourse before 18 yearsClinical Features:Classical triad: Abdominal pain (100%) + Amenorrhea (75%) + Vaginal bleedingQ (7(1%)Classical triad is seen only in 50% casesQAmenorrhea is usually of short period (<6 week)Abdominal pain is acute, agonizing and colicky, located in lower abdomenVaginal bleeding may he slight and continuousDanforth sign: Shoulder pain due to large intraperitoneal hemorrhage (observed in 10% patients)QSite of Ectopic PregnancyName of CriteriaPrimary abdominal pregnancy* Studiford s criteriaQOvarian pregnancy* Spigelberg's criteriaQCervical pregnancy* Rubin's criteriaQDiagnosis:UltrasoundDiagnostic feature on USG: Absence of intrauterine pregnancy with a positive pregnancy fluid in pouch of DouglasQBlob sign: Adnexal mass clearly separated from ovaryQBagel's sign: Typical intact tubal ringQColor Doppler USG: Ring of fire patternQCombination of quantitative hCG and SonographyLowest level of beta-hCG at which gestational sac is visible:For TAS: 6000 IU/LFor TVS: 1000-2000 IU/LBeta-hCG >1500 IU/L with empty uterine cavity is suggestive of ectopic pregnancyQFailure to double the value of beta-hCG by 48-hours with empty uterine cavity: EctopicQSerum Progesterone>25 ng/mLViable intrauterine pregnancyQ<5 ng/mLEctopic or abnormal intrauterine pregnancyQCuldacentesis: Reserved for emergency situation when USG is not possible; positive culdocentesis means bemoperitoneum.LaparoscopyDirect visualization of pelvis especially the tube, feasible in hemodynamically stable patient Gold standard for diagnosis of ectopic pregnancyManagement:Expectant managementMedical TherapySurgical Therapy(Laparoscopically or by microsurgical laparotomy)Systemic Medical Therapy (Methotrexate): CriteriaSalpingocentesis* Salpingostomy:- Procedure of choice in hemodynamically stable patient, who whishes to retain the fertility - Recommended surgical procedure for am pullary ectopic pregnancy* Salpingotomy: Not done nowadays* Segmental resection and anastomosis: Done in isthmic pregnancy* Fimbrial expression: Done in distal ampullary pregnancy1 < 6 wee ks preg nancyQ2. Hemodynamic stabilityQ3. Tubal diameter < 3.5 cmQ4. No fetal cardiac activityQ5. Beta-hCG <15,000 mlU/ mLQ* Local injection of drug in gestational sac * Drugs used are: * MethotrexateQ* Potassium chlorideQ * Actinomycin DQ* PGF-2-alphaQ* Hyperosmolar glucoseQSalpingectomy is done when whole of the tube is damaged; Contralateral tube is normal; Future fertility is not desired.Recurrence:Recurrence of ectopic pregnancy in 10-12% cases
Anatomical difference between right and left side
Difference in blood supply to both sides
Right handedness is more common in population
Some embryological basis
Pathology of Conception