Unplanned pregnancy may play role in poor graft outcomes for younger kidney transplant recipients

Swati Rao

BOSTON — Female kidney transplant recipients who conceived between the ages of 18 and 25 years had higher rates of rejection and graft loss, as well as higher serum creatinine post-pregnancy, than women who were older at the age of conception, according to a speaker at the American Transplant Congress.

“We know that, in the general population, advanced maternal age — defined as older than 35 at age of conception — is associated with increased risk of adverse fetal outcomes,” Swati Rao, MD, transplant nephrologist at the University of Virginia Health System, said during a presentation. “These outcomes can largely be explained by the various comorbidities that come with advanced maternal age. What we don’t know is the impact of maternal age on pregnancy in transplant recipients.”

Using data from the Transplant Pregnancy Registry International, researchers considered pre-pregnancy diagnostics, immunosuppressive regimen and comorbidities during pregnancy in 1,066 recipients. Participants were categorized into one of four groups based on age of conception: 18 to 25 years; 25 to 30 years; 30 to 35 years; or 35 years and older. Maternal, fetal and graft outcomes were compared between groups.

Rao said the results of the study were both “astounding” and “disturbing.”

Although women in all age groups had similar rates of hypertension and pre-eclampsia — and women 35 years and older had a higher incidence of diabetes — women who conceived between the ages of 18 to 25 years had significantly higher rates of rejection during pregnancy (4.9% vs. 1.5%) and after pregnancy (7.4% vs. 0.9%) than those who conceived at age 35 years or older.

In addition, 10.2% of participants in the youngest cohort had graft loss within 2 years after pregnancy compared with 3.9% of participants in the oldest group. Serum creatinine was also highest after pregnancy for those who conceived between 18 and 25 years.

As pregnancy was less likely to be planned for women in the youngest cohort (36% planned vs. 73% for the oldest), Rao posited that this may account for the poorer observed outcomes.

“Unplanned pregnancy means these women may have been less prepared for pregnancy and they may not have been monitored as well as the other cohorts.”

“These poorer transplant outcomes in younger women are alarming,” Rao said. “We should optimize immunosuppression regimens and monitor them more closely during pregnancy. The higher rate of unplanned pregnancy in this age group is definitely a modifiable factor, so efforts to address reproductive health and provide contraceptive counseling are warranted.”– by Melissa J. Webb

Reference:

Rao S, et al. Abstract 325. Presented at: American Transplant Congress. June 1-5, 2019; Boston.

Disclosure: Rao reports no relevant financial disclosures.