Unintended Pregnancy After Kidney Transplant Linked to Mycophenolate Exposure, Not Acute Rejection: Study

"Women with unintended pregnancies were more likely to experience mycophenolate exposure and allograft loss within two years postpartum. However, unintended pregnancy was not associated with acute kidney rejection or overall allograft survival," the researchers wrote in O&G Open.

Unintended pregnancies, which account for about 45% of all pregnancies in the U.S., can lead to significant medical and social challenges, including delays in prenatal care, substance use, and financial burdens. For kidney transplant recipients, unintended pregnancies may pose additional risks for maternal, neonatal, and graft outcomes.

Against the above background, Yalda Afshar, Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, and colleagues aimed to identify risk factors, obstetric complications, and allograft outcomes linked to unintended pregnancy following a kidney transplant.

For this purpose, the researchers conducted a retrospective cohort study of pregnancies in women who had undergone kidney transplantation and were enrolled in the Transplant Pregnancy Registry International, with births between 1967 and 2019. The pregnancies were categorized into intended and unintended groups.

The primary outcome was acute kidney rejection during pregnancy or within 6 weeks postpartum. Secondary outcomes included allograft loss, severe maternal morbidity, and neonatal composite morbidity. The study used multivariable logistic regression, Kaplan–Meier curves, and Cox proportional hazards regression models, adjusting for covariates relevant to the allograft function.

Based on the study, the following findings were made:

• Among 1,723 pregnancies in kidney transplant recipients, 1,081 (62.7%) were intended, and 642 (37.3%) were unintended.
• Risk factors for unintended pregnancy included younger age, Black race, nulliparity, chronic hypertension, and transplant from a deceased donor.
• Exposure to mycophenolate products (16.0% versus 5.7%) and termination (4.7% versus 0.4%) were more common in unintended pregnancies.
• Unintended pregnancy was not associated with acute kidney rejection (2.3% versus 0.9%, adjusted odds ratio [AOR] 2.38).
• Unintended pregnancy was independently associated with allograft loss at 2 years from the end of pregnancy (8.1% versus 3.5%, AOR 2.27), but not allograft survival (adjusted hazard ratio 1.22).
• No differences were found in severe maternal morbidity (3.3% versus 3.6%) or neonatal composite morbidity (12.9% versus 14.3%) between intended and unintended pregnancies.

The findings showed that unintended pregnancy was not linked to acute kidney allograft rejection during the peripartum period but was associated with mycophenolate exposure and allograft loss at 2 years postpartum. Social factors contributing to challenges in accessing reproductive care may also affect transplant health.

"Prepregnancy counseling and continuous follow-up for transplant recipients are recommended to reduce unintended pregnancies and improve long-term transplant outcomes," the researchers concluded.

Reference:

Yin, Ophelia MD; Gliwa, Catherine MD; Walia, Anjali BS; Coscia, Lisa RN, BSN; Constantinescu, Serban MD, PhD; Moritz, Michael MD; Sarkar, Monika MD; Irani, Roxanna MD, PhD; Afshar, Yalda MD, PhD. Unintended Pregnancy After Kidney Transplantation: Risk Factors and Associated Obstetric and Allograft Outcomes. O&G Open 1(4):p 040, December 2024. | DOI: 10.1097/og9.0000000000000040