Study Details Perinatal Risks of Blood Cancers Diagnosed in Pregnancy

Women diagnosed with hematologic cancers during pregnancy had increased risks for serious maternal morbidity and obstetric complications, according to results of a large observational study from France, though their survival outcomes were reassuring.

The adjusted odds of any severe maternal morbidity during hematologic cancer-associated pregnancies was nearly 23 times higher compared with pregnancies in the general population, while the risk for preterm birth was nearly 12 times higher:

• Severe maternal morbidity: 26.2% vs 1.5%, respectively (OR 22.71, 95% CI 17.72-29.10)
• Very preterm birth: 9.8% vs 1.2% (OR 11.90, 95% CI 7.91-17.91)
• Preterm birth: 35.4% vs 5.4% (OR 11.76, 95% CI 9.34-14.81)

However, overall survival (OS) with about 6 years of median follow-up was no different for women diagnosed with a hematologic cancer during pregnancy and those diagnosed after a pregnancy (adjusted HR 0.91, 95% CI 0.62-1.34, P=0.63). Five-year OS rates were 91.2% and 90.3%, respectively, reported Rudy Birsen, MD, of the Cochin Hospital in Paris, and colleagues in Lancet Haematology.

The survival data are “both important and reassuring for women and their families,” Birsen and colleagues wrote. “However, hematological malignancies during pregnancy present a complex situation, with a high risk of maternal and obstetric complications. It is therefore critical that these women receive care in highly specialised centers that are equipped with the necessary human and technical resources to manage both hematological and maternal complications.”

In addition to the findings on severe maternal morbidity and preterm birth, the researchers also found women with a hematologic cancer diagnosed in pregnancy to be at significantly higher risk for intensive care unit admission (30.8% vs 0.7% for pregnancies in the general population), a delivery stay beyond 7 days (40.2% vs 9.8%), pre-eclampsia (4.3% vs 2.1%), psychiatric disorders (6.4% vs 3.2%), malnutrition (4% vs 1.1%), thrombosis (1.8% vs 0.2%), and infections (12.8% vs 8.1%).

“Perhaps the most striking data to emerge from [the] study relates to preterm birth,” wrote Pietro Di Ciaccio, MBBS, of Canberra Hospital, and Georgia Mills, MBBS, of the Northern Beaches Hospital, both in Australia, in a commentary accompanying the study. “Preterm deliveries, whether spontaneous or induced, pose considerable risks of neonatal complications, including respiratory distress, infection, and admission to neonatal intensive care units.”

Rates of spontaneous preterm labor were 13.7% for the hematologic cancer-associated pregnancies versus 3.6% for those among the general population (OR 4.37, 95% CI 3.20-5.98), while rates of induced preterm labor were 18.3% and 1.3%, respectively (OR 16.74, 95% CI 12.65-22.16).

“Importantly, the substantial weight of evidence suggests that the most critical determinant of neonatal well-being and normal neurocognitive outcomes is delivery at term, rather than exposure to chemotherapy in utero, at least after the first trimester,” wrote Di Ciaccio and Mills. “Nevertheless, there might be a tendency in clinical practice to induce labour early to expedite postpartum delivery of chemotherapy and reduce fetal exposure. This is probably misguided in most cases.”

The nationwide cohort study from Birsen and colleagues used the French National Healthcare Data System, which covers up to 99% of the French population, capturing all pregnancies (n=9,996,523) in the nation from 2012 to 2022. They identified 1,366 pregnancy-associated hematologic malignancies (413 during pregnancy and 953 within a year of the end of pregnancy [post-pregnancy]) among the 6 million women included.

Hodgkin lymphoma was the most common hematologic malignancy during pregnancy (39.5% of the 413 pregnancies), followed by acute leukemia (21.6%), aggressive B-cell non-Hodgkin lymphoma (11.6%), myeloproliferative neoplasm (8.7%), myelodysplastic syndrome or chronic myelomonocytic leukemia (5.1%), and indolent non-Hodgkin lymphoma (3.4%).

No survival differences were observed for any specific type of hematologic malignancy occurring during versus post-pregnancy.

Pregnancy-associated deaths were notably higher in women with hematologic malignancies compared with the general population (incidence rate 29.06 vs 0.21 per 1,000 pregnancies), most of which occurred in women with an acute leukemia.

Severe maternal morbidities that were significantly increased for women with a hematologic malignancy compared with the general population included acute respiratory distress syndrome (4.0% vs 0.1%) and need for ventilation (3.1% vs 0.1%), transfusions of blood products (17.7% vs 0.4%), sepsis (6.4% vs 0.5%), disseminated intravascular coagulation (3.1% vs 0.2%), acute renal failure (1.8% vs 0.1%), acute heart failure (1.5% vs 0.1%), conversion of cardiac rhythm and cardiac arrest (0.3% vs

Birsen and colleagues suggested that while their findings contribute to an understanding of pregnancy-associated malignancy, “challenges remain, and many uncertainties need addressing to improve care for women with pregnancy-associated hematological malignancies.”

For example, “recent therapeutic advances, such as CAR T-cell therapy and targeted therapies, remain largely unevaluated in pregnant or lactating women due to their exclusion from clinical trials,” they wrote. “The short-term and long-term effects on children born to mothers with hematological malignancy during pregnancy and exposed to these treatments are critical concerns.”