Risk Factors for Occurrence of Placenta Accrete Spectrum Following Primary Cesarean Delivery
Condition: Placenta Accreta
MeSH terms: Placenta Accreta
Study type: Observational [Patient Registry]

Summary: 
      This study will be conducted on a group of patients undergoing repeat elective caesarean
      delivery attending at Mansoura university hospital.

      - This study will investigate patients' attending to the antenatal care clinic for elective
      termination of pregnancy with history of previous one caesarean delivery in the period
      between (January 2020 till January 2021).
    

Detailed description: 
      Participants in this study will be a group of patients with past history of previous one
      caesarean delivery and attending for elective termination of the current pregnancy.

      Patients data will be collected and analysed as following:

        -  Personal data: Age, residency, job, special habits, BMI

        -  Past obstetric history:

      Gravidity, parity, full term normal delivery, full term assisted vaginal deliveries, preterm,
      stillbirth, abortion, previous pregnancy complication and complication during puerperium •
      Previous delivery: Indication, duration, place of delivery, results of delivery, complication
      during labour, complication during puerperium

        -  Past medical, surgical or gynaecological history

        -  Pregnancy by assisted reproductive techniques

        -  Current pregnancy complications

        -  Trans abdominal and trans vaginal ultrasound examination Patients will be considered to
           have placenta praevia if the lower edge of the placenta is less than 2 cm form the
           internal os of the cervix

      Placenta accreta will be considered as the following(7, 8) (Placental lacunae, Loss of
      hypoechoic space, Abnormalities of uterus-bladder interface, Color Doppler abnormalities)

      2D grey-scale Loss of the "clear zone" Loss or irregularity of the hypoechoic plane in the
      myometrium underneath the placental bed (the "clear zone") Abnormal placental lacunae
      Presence of numerous lacunae including some that are large and irregular (Fin berg grade 3)
      often containing turbulent flow visible in grey-scale imaging Bladder wall interruption Loss
      or interruption of the bright bladder wall (the hyperechoic band or "line" between the
      uterine serosa and the bladder lumen) Myometrial thinning Thinning of the myometrium
      overlying the placenta to <1 mm or undetectable Placental bulge Deviation of the uterine
      serosa away from the expected plane, caused by an abnormal bulge of placental tissue into a
      neighbouring organ, typically the bladder. The uterine serosa appears intact but the outline
      shape is distorted Focal exophytic mass Placental tissue seen breaking through the uterine
      serosa and extending beyond it. Most often seen inside a filled urinary bladder Color Doppler
      imaging Uterovesical hypervascularity Striking amount of colour Doppler signal seen between
      the myometrium and the posterior wall of the bladder. This sign probably indicates numerous,
      closely packed, tortuous vessels in that region (demonstrating multi-directional flow and
      aliasing artifact) Subplacental hypervascularity Striking amount of color Doppler signal seen
      in the placental bed. This sign probably indicates numerous,closely packed, tortuous vessels
      in that region (demonstrating multidirectional flow and aliasing artifact)

      Bridging vessels Vessels appearing to extend from the placenta across the myometrium and
      beyond the serosa into the bladder or other organs. Often running perpendicular to the
      myometrium

      Placental lacunae feeder vessels Vessels with high velocity blood flow leading from the
      myometrium into the placental lacunae, causing turbulence upon entry

      At laparotomy the following data will be reviewed(6):

      Grade 1: Abnormally adherent placenta (placenta adherenta or accreta)

        -  Macroscopically, the uterus shows no obvious distension over the placental bed
           (placental "bulge"), no placental tissue is seen invading through the surface of the
           uterus, and there is no or minimal neovascularity Grade 2: Abnormally invasive placenta
           (Increta)

        -  Abnormal macroscopic findings over the placental bed: bluish/purple colouring,
           distension (placental "bulge")

        -  Significant amounts of hypervascularity (dense tangled bed of vessels or multiple
           vessels running parallel craniocaudially in the uterine serosa)

        -  No placental tissue seen to be invading through the uterine serosa.

        -  Gentle cord traction results in the uterus being pulled inwards without separation of
           the placenta (so-called the dimple sign) Histologic criteria

             -  Hysterectomy specimen or partial myometrial resection of the increta area shows
                placental villi within the muscular fibers and sometimes in the lumen of the deep
                uterine vasculature (radial or arcuate arteries) Grade 3: Abnormally invasive
                placenta (Percreta) Grade 3a: Limited to the uterine serosa Clinical criteria

             -  At laparotomy

        -  Abnormal macroscopic findings on uterine serosal surface (as above) and placental tissue
           seen to be invading through the surface of the uterus

        -  No invasion into any other organ, including the posterior wall of the bladder (a clear
           surgical plane can be identified between the bladder and uterus)

           • Histologic criteria

        -  Hysterectomy specimen showing villous tissue within or breaching the uterine serosa
           Grade 3b: With urinary bladder invasion Clinical criteria

           • At laparotomy

        -  Placental villi are seen to be invading into the bladder but no other organs

        -  Clear surgical plane cannot be identified between the bladder and uterus Histologic
           criteria

             -  Hysterectomy specimen showing villous tissue breaching the uterine serosa and
                invading the bladder wall tissue or urothelium Grade 3c: With invasion of other
                pelvic tissue/organs Clinical criteria

             -  At laparotomy

        -  Placental villi are seen to be invading into the broad ligament, vaginal wall, pelvic
           sidewall or any other pelvic organ (with or without invasion of the bladder) Histologic
           criteria • Hysterectomy specimen showing villous tissue breaching the uterine serosa and
           invading pelvic tissues/organs (with or without invasion of the bladder) .For the
           purposes of this classification, "uterus" includes the uterine body and uterine cervix .

             -  The data will be analysed after putting it in the following groups,

             -  study group consisted of patients with placenta praevia diagnosed by TVUS, control
                group consisted of patients undergoing elective caesarean delivery without having
                placenta praevia by transvaginal ultrasound (TVUS) examination
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        This study will be conducted on a group of patients undergoing repeat elective cesarean
        delivery attending at Mansoura university hospital.

        - This study will investigate patients' attending to the antenatal care clinic for elective
        termination of pregnancy with history of previous one cesarean delivery
      
Keywords: placenta accrete spectrum; ultrasound; Risk factors