The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche”   Andrea KAELIN AGTEN1 Giuseppe CALI2 Ana MONTEAGUDO1,3 Johana OVIEDO1 Ilan E. TIMOR-TITSCH1 1. Department of Obstetrics and Gynecology, NYU School of Medicine, New York, NY 2. Department of Obstetrics and Gynecology, ARNAS Civico, Palermo, Italy. 3. Maternal Fetal Medicine Associates, Carnegie Hill Imaging for Women, New York, NY

Background “Cesarean scar pregnancy” (CSP) = placental implantation within the scar of a prior cesarean delivery. Rising numbers of cesarean deliveries  increased incidence of CSPs. Complications of CSP: morbidly adherent placenta, uterine rupture, severe hemorrhage, and preterm labor. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E.  The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche.  AJOG 2017 7

Background It is suspected that CSPs implanted within a dehiscent scar (“niche”) behave differently compared to those implanted on top of a well healed scar. To date there are no studies comparing pregnancy outcomes between CSPs implanted either “on the scar”, or “in the niche”. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Objective To determine the pregnancy outcome of CSP implanted either “in the scar” or “in the niche”. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Material and Methods Retrospective, multi-center study of 17 patients with CSP diagnosed between 5-9 weeks gestation (median 8 weeks). All CSPs were categorized as either implanted or “on the scar” (Group A) or “in the niche” (Group B) based on their 1st trimester transvaginal ultrasound. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Cesarean scar pregnancy implanted “on the scar” KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Cesarean scar pregnancies implanted “in the niche” KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Material and Methods Clinical outcomes between group A and B were compared (Mann-Whitney U-test): gestational age at delivery mode of delivery blood loss at delivery neonatal weight placental histopathology KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Material and Methods Myometrial thickness overlying the placenta was compared between all the patients requiring hysterectomy and those who did not (Mann-Whitney U test). KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results Group A: “on the scar” = 6 patients Group B: “in the niche” = 11 patients KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results Maternal age Gestational age at diagnosis Group A: 34 years (median; range 20-42 years) Group B: 35 years (27-42 years), p=0.880 Gestational age at diagnosis Group A: 8 weeks (6-9 weeks’ gestation) Group B: 7 weeks (5-9 weeks’ gestation), p=0.679 KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

1 for focal placenta Accreta Results Group A On the scar Group B In the niche P value n 6 11 GA at diagnosis (weeks) 8 7 0.679 GA at delivery (weeks) 38 34 0.001 Cesarean delivery 10 Cesarean hysterectomy 1 for focal placenta Accreta 10 for adherent placenta + 1 gravid hysterectomy at 20 weeks for bleeding Blood loss (ml) 700 (300-4000) 1200 (270-2850) 0.117 Neonatal weight (g) 3220 (2900-3570) 2450 Myometrial thickness (mm) 5 (range 4-9) 1 (range 0-2)

Results Prior cesarean deliveries group A had a median of 1.5 prior cesarean deliveries (range 1-2). group B 1.0 prior cesarean delivery (range 1-4), p=0.884. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results Group A: Patients in group A showed no sonographic signs of morbidly adherent placenta and had no antepartum complications. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results Group A: 5 (83%) delivered by cesarean delivery and 1 (17%) by cesarean-hysterectomy due to incomplete removal of the placenta and intractable hemorrhage. The patient with cesarean-hysterectomy had a myometrial thickness of only 2mm in the 1st trimester ultrasound scan Partial placenta accreta was histologically confirmed in a small area. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results Group B: all patients underwent hysterectomy. 10 patients underwent cesarean-hysterectomy with histologically confirmed placenta increta or percreta. 1 patient had a gravid-hysterectomy for severe vaginal bleeding at 20 weeks, and the histology revealed placenta percreta. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results Blood loss in group B median 1200ml (300-4000ml) Blood loss in group A: median 700ml (600-1400ml), p=0.117. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Results The myometrium was thinner group B than group A 1mm vs. 5mm (median); p=0.001. Myometrial thickness showed a positive correlation with gestational age (r=0.820, p<0.0005). Neonatal weight was higher in group A than group B 3220g vs. 2450g (median); p=0.001. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Example of a patient with CSP implanted “on the scar” with a normal placenta at delivery. Grey scale image of them placenta implanted “on the scar” at 10 weeks (a). Color Doppler evaluation of the placenta at 14 weeks (b and c). Image of the placenta and cervix at 22 weeks (d). At 28 weeks the placenta moved upwards (e). At 32 weeks no signs of morbidly adherent placenta at the site of the scar (f). KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Example of a patient with cesarean scar pregnancy (CSP) implanted “in the niche” with placenta percreta at delivery. Grey scale image of CSP implanted “in the niche” at 9 weeks. In the second trimester signs of morbidly adherent placenta are demonstrated (b, c): vascular lacunae, interrupted bladder line, myometrial thinning, and utero-vesical hypervascularity. Uterus specimen after delivery (d). KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Discussion Expectant management of CSP was shown to offer the possibility to deliver a live-born neonate, though with considerable risk for hysterectomy. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Discussion In our study 16 of 17 (94.1%) patients managed expectantly delivered a live neonate. Zosmer et al. reported live neonate in all patients. Michaels et al. reported only 62.5% live births. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Discussion Study Strengths : Two major centers with experience in CSP. 2. Largest published cohort of expectantly managed CSP. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Discussion Limitations: Small sample size. Possible surgeon-depended differences in surgical techniques of cesarean delivery and cesarean-hysterectomy. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Conclusion Patients with CSP implanted “on the scar” had a substantial better outcome compared to patients with CSP implanted “in the niche”. Myometrial thickness below 2mm in the 1st trimester ultrasound was associated with morbidly adherent placenta at delivery. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017

Conclusion Our results can be helpful when counseling patients with CSP. CSP implanted on the scar and with a myometrial thickness >4mm may be good candidates for expectant management. KAELIN AGTEN A., CALI G., MONTEAGUDO A., OVIEDO J. TIMOR-TITSCH I.E. The clinical outcome of cesarean scar pregnancies implanted “on the scar” versus “in the niche. AJOG 2017