Skip to content

Impact of a Previous CS on the Ongoing Pregnancy Rate in Single Euploid Frozen Embryo Transfer (ET)

To Study the Impact of a Previous Cesarean Section (CS) With / Without an Isthmocele on the Ongoing Pregnancy Rate in Single Euploid Frozen Embryo Transfer

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05798624
Enrollment
1050
Registered
2023-04-04
Start date
2023-05-01
Completion date
2025-07-30
Last updated
2024-07-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Implantation, Infertility

Keywords

Implantation, Infertility, Isthmocele, Cesarean section

Brief summary

As embryo ploidy is a crucial factor not only for implantation but also for maintenance of a pregnancy, the aim of this study is to evaluate the impact of the CS / isthmocele on the ongoing pregnancy rates and the implantation site in single euploid frozen embryo transfer, independent of the endometrial preparation approach.

Detailed description

The impact of a previous CS on the future fertility in the general population is discussed controversially, but it seems that the clinical and social circumstances leading to the CS have a greater effect on future fertility than the surgical procedure itself (Gurol-Urganci et al., 2013, 2014; Evers et al., 2014). However, this might be different in women who do not conceive spontaneously after a previous CS and need to undergo ART due to secondary infertility. Whereas some studies describe a reduction of implantation, ongoing pregnancy, and live birth (LB) rates (Vissers et al., 2020; Wang et al., 2020; Diao et al., 2021; Friedenthal et al., 2021; van den Tweel et al., 2022), others describe a negative impact of a previous CS only in the presence of an isthmocele (Diao et al., 2021) or no impact (Patounakis et al., 2016). A case control study evaluated whether there are any differences in the location and distance to the internal cervical ostium of the implantation site of the intrauterine gestation sacs, early pregnancy symptoms and pregnancy outcome at 12 weeks gestation between women with and without a previous Caesarean section (CS) in patients who conceived naturally (Naji et al., 2013). Investigators concluded that the presence of a CS scar affects the site of implantation, and also that the distance between implantation site and the scar is related to the risk of spontaneous abortion. This is a purely observational study without any intervention. Participants will be stratified into different groups according to their previous obstetrical history. Total sample size will include 1050 participants undergoing a frozen embryo transfer (FET) cycle. Isthmocele will be defined according to de Vaate et al (Bij de Vaate et al., 2011) as: visible anechogenic area of at least 1 mm depth at the site of the Cesarean scar.

Interventions

DIAGNOSTIC_TESTUltrasound between 6+0 and 6+7 weeks of pregnancy - With Isthmocele

Location of implantation of the GS (gestational sac) amended to Naji et al, defined as 3 possible implantation sites: (A: fundal, B: anterior, C: posterior) Size of isthmocele: * Depth of isthmocele * Width of isthmocele * Circumference of isthmocele Distance between isthmocele and outer cervical os (measured with the trace line) Distance between CS scar and outer cervical os (measured with the trace line) Size of gestational sac Measurements of the isthmocele size / circumference / distance between isthmocele / CS and outer cervical os

DIAGNOSTIC_TESTUltrasound between 6+0 and 6+7 weeks of pregnancy - Without Isthmocele

Location of implantation of the GS amended to Naji et al, defined as 3 possible implantation sites: (A: fundal, B: anterior, C: posterior) Distance between CS scar and outer cervical os (measured with the trace line) Size of gestational sac

DIAGNOSTIC_TESTUltrasound between 6+0 and 6+7 weeks of pregnancy

Location of implantation of the GS (gestational sac) amended to Naji et al, defined as 3 possible implantation sites (A: fundal, B: anterior, C: posterior) Size of gestational sac

Sponsors

ART Fertility Clinics LLC
Lead SponsorOTHER

Study design

Observational model
OTHER
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 42 Years

Inclusion criteria

\- All participants undergoing a single euploid FET, independent of the endometrial preparation approach

Exclusion criteria

* Intracavitary fluid during preparation for FET * Known anomaly of the uterus or the adnexae (e.g.: fibroids, polyps, hydrosalpinx, endometriosis, adenomyosis) * Embryo which was biopsied on day 7 * Poor quality embryo which was transferred (Gardner criteria: AC / BC / CB, biopsied on day 6 and CC embryos from both, day 5 and day 6 biopsies, classified as poor quality embryos) * History of recurrent abortion * Antiphospholipid syndrome / autoimmune diseases

Design outcomes

Primary

MeasureTime frameDescription
Ongoing pregnancy rate5 weeks
Implantation rate6 weeksNumber of gestational sacs observed by ultrasound at 6 weeks of gestation divided by the number of embryos transferred
Implantation site6 weeks
Rate of vaginal bleeding in early pregnancy (until 12 weeks of gestation)12 weeks

Countries

United Arab Emirates

Contacts

Primary ContactBarbara Lawrenz, PhD
barbara.lawrenz@artfertilityclinics.com+971 2 652 8000
Backup ContactJonalyn Edades
jonalyn.edades@artfertilityclinics.com+971 2 652 8000

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026