Pregnancy for women with cystic fibrosis

A pending prospective, multi-center study will assess whether mothers with cystic fibrosis can maintain their health if they become pregnant.

The $9 million trial, titled “The Maternal and Fetal Outcomes in the Era of Modulators (Mayflowers) Study,” is being funded by the Cystic Fibrosis Foundation (CFF).

“The first documented case of a woman who had cystic fibrosis and became pregnant was in the 1960s. But she passed away less than 2 months after the birth of her child,” said co-principal investigator Jennifer L. Taylor-Cousar, MD, MSCS, a pulmonologist at National Jewish Health in Denver, Colorado.

Taylor-Cousar noted that today more than 50% of women with cystic fibrosis are aged 18 or older. “We have new medications that we hope will help people live closer to full life expectancy,” she said.

In addition, every year the number of women with cystic fibrosis who become pregnant is increasing, according to registry data, from 310 women in 2019 to over 600 in 2020.

The Mayflowers study, which will begin in July and end in December 2025, will enroll 285 women with cystic fibrosis at 40 sites across the United States. The women will be followed through pregnancy and 2 years after giving birth to document their health changes.

The study team expects that about 25% of the women will stop taking their cystic fibrosis transmembrane conductance regulator (CFTR) modulator during part or all of their pregnancy. “CFTR modulators are a new class of drugs that impacts the basic defect in cystic fibrosis and has been shown to have profound effects on lung function, weight and quality of life,” Taylor-Cousar told Contemporary OB/GYN®.

Although many new moms experience exhaustion or lose weight, these issues are compounded for those with cystic fibrosis, “who need to complete hours of therapies to maintain health, and have the baseline challenge to maintain one’s weight because of the lack of pancreatic enzymes with which most people with cystic fibrosis are born,” Taylor-Cousar said.

There is no published data in human women whether all 3 components of the newest CFTR modulator are transferred to the baby through the placenta or breast milk, according to Taylor-Cousar. “Furthermore, only small retrospective surveys have reported use of CFTR modulators in pregnancy, limiting our understanding of the impact of modulators on outcomes for infants exposed in utero and during lactation,” she said.

A substudy of 20 mother-and-infant pairs will evaluate the pharmacokinetics of modulators in pregnant women and in the infants exposed to modulators for women who choose to continue them during pregnancy and breastfeeding.

The study expects to show that it is safe for a woman to stay on her medications, especially one of the new modulators, and not experience a significant health decline during pregnancy, particularly in the first year after her child is born.

The study will evaluate diabetic women with cystic fibrosis as well. “We know that about 30% of adult women with cystic fibrosis also have diabetes, which is something else that has not been widely studied in women with cystic fibrosis during pregnancy,” Taylor-Cousar said.

A substudy of about 100 diabetic women will use continuous glucose monitoring. “We hope this substudy will provide evidence-based data for managing diabetes during pregnancy that is specific to the unique needs of women with cystic fibrosis,” she said.

The Mayflowers study will provide definitive data to guide women and their partners in their decision-making. “We also sincerely hope that one of the ancillary benefits of the study will be to truly improve the communication between cystic fibrosis center-care teams and ob/gyns,” Taylor-Cousar said.

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Disclosure

In the last 3 years, Taylor-Cousar reports grants to her institution from the Cystic Fibrosis Foundation (CFF), Eloxx, Vertex, N30 and Bayer; grants to her institution and personal fees (advisory boards/clinical trial design consultation/non-branded speaking) from Gilead, Vertex, Celtaxys and Proteostasis, and personal fees (advisory boards/clinical trial design consultation/data monitoring committee) from Novartis, Genentech, Protalix, Santhera, 4DMT, Polarean, Insmed, and AbbVie. She is an advisor to the CFF Board of Trustees, CFF Clinical Research Advisory Board, and serves on the CF TDN Clinical Research Executive Committee, and as Chair of the CF TDN Women’s Health Research Working Group. She also serves on the American Thoracic Society’s Clinical Problems Assembly Program and Scientific Advisory committees.