CRISTEL Study: Monitoring of Pregnancies in Women After Solid Organ Transplantation (CRISTEL)

The objective of this research is to obtain standardized and independent data on the number of pregnancies occurring in France and their follow-up up to 1 year postpartum (or post-pregnancy termination). This study will then aim to describe the clinical characteristics and maternal and perinatal outcomes of pregnancies in this specific population. These data will enable the dissemination of clear and up-to-date information to the medical community, thus contributing to better patient counseling and, more broadly, to couples. They will also serve to issue recommendations to optimize the planning and follow-up of pregnancies in women with solid organ transplants. Finally, this initiative aims to promote clinical research on pregnancies.

Study Overview

• Status: Not yet recruiting
• Conditions: Surgical Operation With Transplant of Whole Organ
• Intervention / Treatment: Other: Blood sample

Detailed Description

According to North American and Australian registries, pregnancy is both a joyful and high-risk event for women who have received a solid organ transplant. Typically, a transplanted woman has a probability comparable to that of the general population of giving birth to a live infant, but she is likely to deliver prematurely (median gestational age: 32 weeks), to have a growth-restricted baby (median birth weight around 2.3 kg), and often in a context of preeclampsia (in at least 30% of cases)(1).

Today, these are the data shared with patients planning a pregnancy, despite uncertainty as to their accuracy and applicability in France or even Europe.

Among the unknowns that remain despite these registry data, the following should be noted:

Uncertainty about the level of pregnancy planning in this specific context: What proportion of women of childbearing age have been informed of the possibility of becoming pregnant, of the associated risks, and of necessary precautions (e.g., stopping mycophenolate mofetil at least 6 weeks before conception);

Variability in the information provided from one center to another, due to the absence of a national, consensus-based document addressing fertility and contraception in the post-transplantation setting;

Monitoring frequency specific to the graft, especially regarding exposure to immunosuppressive drugs (and consequently actual exposure to calcineurin inhibitors, the cornerstone of anti-rejection therapy, whose residual blood concentration varies from the second trimester onward)(2);

The true risk of preeclampsia, at a time when diagnosis can be refined by measuring levels of placental-derived anti-angiogenic factors in maternal serum (sFlt-1/PlGF ratio)(3), and by uterine artery Doppler;

The incidence of de novo anti-HLA immunization (HLA antigens expressed by the fetus and inherited from the father), which can now be assessed using the Luminex technique(4);

Maternal morbidity: What is the impact of pregnancy on graft function? Conversely, how does renal function influence pregnancy outcomes, regardless of the transplanted organ?

Infant morbidity in the short and medium term.

To establish these data and to provide accurate information to patients, we aim to conduct a study among pregnant women who have undergone solid organ transplantation (kidney, heart, lung, liver, or pancreas). The objective of this research is to collect standardized and independent data on the number of pregnancies occurring in France and to monitor them up to one year postpartum (or after pregnancy termination).

The study will then aim to describe the clinical characteristics and maternal and perinatal outcomes of pregnancies in this specific population. These data will help disseminate clear and up-to-date information to the medical community, thus improving patient counseling and, more broadly, support for couples. They will also serve to develop recommendations to optimize the planning and management of pregnancies in women with solid organ transplants.

Finally, this initiative aims to promote clinical research on pregnancy in the context of transplantation, particularly through clinical trials and the development of biobanks.

• Study Type: Interventional
• Enrollment (Estimated): 2000
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Sahar Pr SELLAMI JALLOULI, PhD; Phone Number: 01 46 25 31 37; Email: s.sellami-jallouli@hopital-foch.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Female patient aged 18 years or older and of childbearing age
• Has received a solid organ transplant, either isolated or combined (heart, liver, lung, pancreas, kidney)
• Has a positive blood beta-hCG test result > 5 IU/L ("positive")
• Has signed an informed consent form
• Affiliated with a health insurance plan

Exclusion Criteria:

• Patient deprived of liberty or under legal guardianship
• Patient refuses to participate in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Other: Adult female patients who have received a solid organ transplant; Adult female patients who have received a solid organ transplant, either isolated or combined (heart, liver, lung, pancreas, kidney), and who present with a positive beta-hCG blood test result (defined by a threshold of 5 IU/L) in one of the participating centers, or who are planning a pregnancy, will initially be identified.

Other: Blood sample; Two optional (non-mandatory) biological samples may be collected as part of this study: A 2 mL venous blood sample may be taken during a routine prenatal follow-up visit (around 30 weeks of gestation) in order to analyze the preeclampsia biomarker (sFlt-1/PlGF ratio), whenever preeclampsia is suspected. A 5 mL sample from cord blood may be collected after delivery to analyze, in the newborn, the complete blood count, white blood cell differential, lymphocyte phenotyping (T CD3+, CD19+CD20+, and NK CD46+), and immunoglobulin levels (G, A, and M for humoral immunity, and E for allergy-related function).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The primary outcome is the annual incidence of conception in the population of women with solid organ transplants (i.e., included in the study).	The primary outcome is the annual incidence of conception in the population of women with solid organ transplants (i.e., included in the study).	Annually over the 10-year study period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of preeclampsia	Rate of preeclampsia	Through study completion, an average of 1 year
Trajectory of estimated glomerular filtration rate (eGFR, in mL/min/1.73 m²);	Trajectory of estimated glomerular filtration rate (eGFR, in mL/min/1.73 m²);	3 months and 12 months postopartum
Live birth rate among transplanted mothers from the onset of pregnancy.	Live birth rate among transplanted mothers from the onset of pregnancy.	through study completion, an average of 1 year
Trajectory of serum creatinine levels	Trajectory of serum creatinine levels	During pregnancy (up to 40 weeks if gestation)
Rate of maternal complications before delivery and in the postpartum period (infectious episodes, rejection episodes, therapeutic pregnancy termination, postpartum hemorrhage)	Rate of maternal complications before delivery and in the postpartum period (infectious episodes, rejection episodes, therapeutic pregnancy termination, postpartum hemorrhage)	During pregnancy (up to 40 weeks of gestation) and during post partum from delivery up to about 1 year after birth
Mode of delivery (spontaneous labor, induced labor, planned cesarean section, or emergency cesarean section); gestational age at delivery (in weeks of gestation); proportion of gestational hypertension and preeclampsia.	Mode of delivery (spontaneous labor, induced labor, planned cesarean section, or emergency cesarean section); gestational age at delivery (in weeks of gestation); proportion of gestational hypertension and preeclampsia.	Day of delivery: Perioperative/Periprocedural
Birth weight of the newborn (in grams)	Birth weight of the newborn (in grams)	day of delivery
Rate of spontaneous miscarriage	Rate of spontaneous miscarriage	Through study completion, an average of 1 year
Rate of cesarean section	Rate of cesarean section	Through study completion, an average of 1 year
Rate of prematurity	Rate of prematurity	Through study completion, an average of 1 year
Rate of intrauterine growth restriction	Rate of intrauterine growth restriction	Through study completion, an average of 1 year
the duration of hospital stay for both the mother and the newborn	the duration of hospital stay for both the mother and the newborn	Through study completion, an average of 1 year
incidence of biopsy-proven acute rejection up to 12 months postpartum;	incidence of biopsy-proven acute rejection up to 12 months postpartum;	up to 12 months postpartum;
incidence of de novo anti-HLA sensitization at 3 and 12 months postpartum.	incidence of de novo anti-HLA sensitization at 3 and 12 months postpartum.	3 months and 12 months postoartum
Trajectory of proteinuria (protein-to-creatinine ratio)	Trajectory of proteinuria (protein-to-creatinine ratio)	During pregnancy (up to 40 weeks if gestation)
Trajectory of tacrolimus blood levels, and anti-angiogenic factors during pregnancy,	Trajectory of tacrolimus blood levels, and anti-angiogenic factors during pregnancy,	During pregnancy (up to 40 weeks if gestation)
Trajectory of anti-angiogenic factors during pregnancy	Trajectory of anti-angiogenic factors during pregnancy	During pregnancy (up to 40 weeks if gestation)
Rate of maternal complications and hospitalizations before delivery and in the postpartum period (infectious episodes, rejection episodes, therapeutic pregnancy termination, postpartum hemorrhage)	Rate of maternal hospitalizations before delivery and in the postpartum period	During pregnancy (up to 40 weeks of gestation) and during post partum from delivery up to about 1 year after birth
Apgar score	Apgar score	day of delivery
Proportion of growth-restricted	Proportion of growth-restricted	day of delivery and up 3 month postpartum
Incidence of neonatal complications before the third month of life	Incidence of neonatal complications before the third month of life	day of delivery and up 3 month postpartum

Collaborators and Investigators

• Sponsor: Hopital Foch
• Investigators: Principal Investigator: Alexandre Pr Hertig, MED, Foch Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2036
• Study Completion (Estimated): September 1, 2036

Study Registration Dates

• First Submitted: September 22, 2025
• First Submitted That Met QC Criteria: May 11, 2026
• First Posted (Actual): May 18, 2026

Study Record Updates

• Last Update Posted (Actual): May 18, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Investigative Techniques; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Blood Specimen Collection
• Other Study ID Numbers: 2023_0004

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No