NCT05798624

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
• Phase: —
• Study type: Observational
• Enrollment: 1,050 (estimated)
• Sponsor: ART Fertility Clinics LLC · Academic / Other
• Sex: Female
• Age: 18 Years – 42 Years
• Healthy volunteers: —

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.

Conditions

• Infertility
• Implantation

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Ultrasound 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_TEST	Ultrasound 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_TEST	Ultrasound 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

Timeline

• Start date: 2023-05-01
• Primary completion: 2025-05-15
• Completion: 2025-07-30
• First posted: 2023-04-04
• Last updated: 2024-07-17

Locations

1 site across 1 country: United Arab Emirates