(NaturalNews) Did a recent study published in the New England Journal of Medicine prove that chemotherapy is safe during pregnancy? That's certainly what media reports — and the researchers themselves — would have you believe. Some reports have even claimed that the study proves all cancer treatments, including radiation, are safe for pregnant women.

"Our results show that fear of cancer treatment is no reason to terminate a pregnancy, that maternal treatment should not be delayed and that chemotherapy can be given," lead researcher Frederic Amant said.

But a closer look at the published study reveals that the data actually show no such thing.

What do they say they found?

The research was a follow-up from a prior study in which data were pooled together from different tests performed on children of different ages. This time, the researchers instead focused only on children up to three years old. Thus, even if its methodology were flawless, the study could at best show that no ill effects are seen from in utero exposure to chemotherapy within the first three years of life. Longer-term developmental or immune effects could not be tested or accounted for by this methodology.

The researchers compared various health outcomes in children whose mothers had undergone cancer treatment during pregnancy with those of children whose mothers were cancer-free. The study found no difference between the two groups in terms of cognitive outcome; birth weight, length and head circumference; or incidence of medical problems and need for medical care. No connection was found between these outcomes and the number of chemotherapy cycles undergone by the mothers, which ranged from one to ten.

There's just one problem: the researchers did not actually compare chemotherapy with non-chemotherapy patients.

What did they really find?

The study was conducted on a small sample of pregnant women with widely varying cancer types — 18 in all. There were 69 cases of breast cancer, with the next most prevalent cancer type consisting of only 10 cases and most types represented by only one or two cases.

Only 42 percent of the children were actually compared at the age of three years; the rest were compared at the age of 18 months due to a lack of follow-up data. Thus, even the modest claim that no ill effects were seen up to three years is an exaggeration.

The most fundamental problem with the study, however, is the way that "chemotherapy" was defined. In actuality, the "chemotherapy" group consisted of 129 women whose mothers had cancer while pregnant with them, whether those mothers got chemotherapy or not. In fact, only 74.4 percent of children in the "chemotherapy" group were exposed to chemo at all. Another 8.5 percent were exposed to radiation, 1.6 percent were exposed to other drugs, 10.1 percent had mothers who underwent only surgery and 10.9 percent had mothers who underwent no treatment. Thus, fully 21 percent of the "cancer treatment" group included children whose mothers did not undergo any chemical or radiological cancer treatment.

To top it off, the researchers admit that there was a much higher than normal rate of preterm delivery in the cancer group — 61.2 percent of children were born preterm, compared with average rates of only 6.8 to 8.0 percent in the countries where the study took place.

Preterm delivery is linked with significantly poorer infant health outcomes. But rather than comparing the children to babies born to cancer-free mothers at full term, the researchers compared them to children of the same gestational age, thereby masking any health effects of cancer-related preterm delivery.

Notably, many of the preterm deliveries were induced by doctors, in order to give mothers doses of cancer treatment known to be damaging to unborn children.

Finally, the study found higher rates of heart abnormalities in the cancer group than in the non-cancer group, a fact media reports have mostly ignored.

Were these abnormalities linked to the cancer treatment, or to the cancer itself? Due to the study's poor design, it is impossible to know.

Sources used:

DailyMail.co.uk

Reuters.com

NEJM.com