1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. Results Maternal age Gestational age at diagnosis
Group A: 34 years (median; range 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

12. 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
( )
1200
( )
0.117
Neonatal weight (g)
3220
( )
2450
Myometrial thickness (mm) 5
(range 4-9) 1
(range 0-2)

13. 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

14. 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

15. 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

16. 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

17. Results Blood loss in group B median 1200ml (300-4000ml)
Blood loss in group A:
median 700ml ( ml), 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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