Women With CKD Receiving Fertility Treatment Have Similar Birth Rates to Those Conceiving Naturally

Findings from a new systematic review suggest that women with chronic kidney disease (CKD) receiving fertility treatment have similar pregnancy outcomes compared with women with the disease who conceive naturally. This study was recently published in Journal of Nephrology.

However, the researchers, underscoring a need for prospective data, noted that women with CKD tended to have higher rates of preterm delivery and lower birthweight. Their findings resulted from a review of 84 fertility treatment cycles among 68 women published in 32 publications.

Approximately 3 in 4 women (71.4%) became pregnant during fertility treatment, with a live birth rate of 85%. According to the group, the rate of live births and miscarriage, occurring in 12 of the women with CKD, were similar to that of women who conceived naturally, although they flagged that reporting bias likely confounded their findings.

Fertility treatments used by women included in vitro fertilization and intracytoplasmic sperm injection (79.4%), ovulation induction (10.1%), and intrauterine insemination (2.9%). One woman had a frozen embryo transfer, and another woman received auto-transplantation of cryopreserved ovarian tissue. Among the 51 births, there were 70 babies, with 13 sets of twins and 3 sets of triplets. More than one-third (38.3%) of pregnancies were complicated by hypertensive disorders.

“Although most pregnancies resulted in live birth, fetal and maternal adverse outcomes were common,” explained the researchers, adding, “The rate of preeclampsia (P = .001) was significantly higher (P <.05) in the ART [assisted reproductive technology] CKD cohort compared with women with CKD who had conceived naturally. However, it is also noted that patients who developed preeclampsia had lower eGFRs [estimated glomerular filtration rates]; hence, this may have been a contributing factor as well as possibly ART.”

Preterm birth was also more common among the women with CKD. Twenty-four (35.3%) women gave birth less than 37 weeks into pregnancy, a rate that is 7-fold higher than that of the general population in the United States (3.8%). The researchers noted that early preterm (under 34 weeks) birth rates were also significantly higher among women with CKD receiving fertility treatment than among women without the disease and among women with CKD who conceived naturally.

“High preterm delivery rates could also be attributed to the rates of multifetal pregnancies (26.7%) in our cohort,” detailed the researchers. “It is well known that increased maternal age and ART have increased the incidence of twin pregnancy by more than 50%, but most recent Human Fertilisation and Embryology Authority reports suggest that multifetal pregnancies represent only 6% of ART pregnancies. In the last decade, there has been an increasing drive towards single embryo transfer, especially in the United Kingdom and the United States, which has led to a steep reduction in higher-order pregnancies.”

The researchers observed a higher rate of low birthweight among women with CKD receiving fertility treatment compared with women without the disease who receive fertility treatment. A possible driver behind the finding, wrote the researchers, was the higher preterm birth rate and multifetal pregnancies occurring among these women.

Reference

Bhaduri M, Gama R, Copeland T, et al. Systematic review of pregnancy and renal outcomes for women with chronic kidney disease receiving assisted reproductive therapy. J Nephrol. Published online November 18, 2022. doi:10.1007/s40620-022-01510-x