Lower Childbirth Rates Shown in Women With MPNs

Rates of childbirth were reported to be lower among women with myeloproliferative neoplasms (MPNs), according to a recent study in the journal Leukemia, which emphasized MPN management before and during pregnancy.

The researchers from the study noted that managing MPN before and after pregnancy may improve birth rates and may also reduce the risk of complications for the mother who has MPNs.

MPNs occur when the bone marrow produces too many red blood cells, platelets and/or certain white blood cells. This type of disease may worsen with time as the excess cells build up in the blood or bone marrow. MPNs may include polycythemia vera (PV) and essential thrombocythemia (ET) and may become acute myeloid leukemia, the National Cancer Institute explained.

The study included 1,141 women with MPNs and 4,564 controls — age-matched women from Sweden. At diagnosis and age matching, the median age was 36 years old. Specifically, 268 patients had PV, 620 had ET, 120 had primary myelofibrosis (PMF) and 133 had unclassifiable MPNs.

“Taken together, the results enable informed conversations on family planning and prognosis of childbearing and pregnancy and convey a message that childbirth with low risks of complications is possible in the majority of patients with MPNs,” the researchers wrote in the study.

READ MORE: New Drug May Decrease Need for Blood Draws in Patients With PV

Childbirth rates were reduced by 22% in patients with MPNs, compared with controls in the study. The researchers found that there were 221 childbirths in patients with MPNs and 1,131 childbirths among the controls.

In terms of the MPN subtype, researchers noted that ET was the most common subtype among the patient cohort. They found that “interestingly, in ET patients, childbirth rates were similar to controls.” Patients with ET had higher childbirth rates than patients with other MPN subtypes, for which their childbirth rates were “significantly reduced,” the researchers wrote.

Miscarriages and stillbirths were also more prevalent among patients with MPNs than controls, the researchers reported. During a follow-up of five years, researchers noted 43 events of miscarriage in 705 women with MPNs and 140 in 2,820 controls.

“Overall, women with MPN had a lower number of children compared to the control population,” researchers wrote. “There was no significant difference in the risk of miscarriage before or after MPN diagnosis in relation to the controls.”

Of note, a study from the American Journal of Hematology stated that miscarriages have occurred in 20% to 30% of patients with ET and occurred in 12% to 30% of patients with PV.

Eleven women with MPNs (1%) experienced stillbirth when they received their diagnosis, the study stated. Sixteen controls experienced stillbirth (0.4%), which the researchers noted was “a statistically significant difference.”

READ MORE: Gut Microbiota Differs in Patients With MPNs

“Theoretically, a lower birthrate in MPN patients in combination with a similar rate of miscarriages could constitute an excess risk of miscarriage,” wrote the researchers. “There is also a risk of underreporting of miscarriages, however we have no reason to believe that there are any major differences in medical attention-seeking behaviors regarding miscarriages between MPN patients and controls.”

Based on the study’s findings, the researchers recognized that patient attitudes towards reproductive choices may have been a consideration but that is still not determined.

“One question that is difficult to address through register-based data is if having an MPN diagnosis affects the women’s attitudes and reproductive choices, thus if women choose not to have children due the MPN diagnosis,” they wrote. “There is also a question whether there could be an underlying MPN-related biological effect on fertility and the possibility of conceiving a child, or maintaining pregnancy as has been reported in other diseases with thrombotic implications.”

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