Male fetuses Late miscarriages more common

In males, late miscarriages are more common

01/12/2014

In a new British study, scientists have found that miscarriages are more common in male fetuses. According to the researchers, the risk is about ten percent higher. The causes are not clear.

Late miscarriages are especially difficult for parents
Miscarriages are fundamentally dramatic burdens on the affected parents. The later that happens, the more they suffer. As the "Hamburger Abendblatt" reported, not a few of the miscarriages take place even after the fifth month of pregnancy. At a time, then, when most parents think they are safe. In 2009, it hit 2.6 million unborn children worldwide. This is similar to the number of babies who die from sudden infant death after birth. For scientists, late miscarriages are still a mystery. Early premature births are reported to be often triggered because the fetus has malformations or chromosomal abnormalities. In late miscarriage, however, little is known about why they occur and why only so late.

30 million pregnancies examined
To better understand the phenomenon, a research team headed by Fiona Mathews from the University of Exeter in the UK has now studied more than 30 million pregnancies and their outcome. The scientists report in the journal "BMC Medicine" that late miscarriages are more common in boys than girls. According to the risk is about ten percent higher. This corresponds to approximately 100,000 male stillbirths per year worldwide. In the respective countries, the data had different definitions for late miscarriage, for example a birth weight of at least 400 or 500 grams or the 20th to 28th week of gestation.

Proportion of stillbirths in richer countries lower
However, as the researchers emphasized, the gender difference in the different time windows is the same. According to this, on average 6.23 out of 1,000 births were stillbirth and 5.74 for the girls. The proportion of stillbirths in the richer nations was generally much lower than in the poorer ones. For example, only two out of every 1,000 children in Finland were born prematurely pregnant, but more than 40 in Nigeria and Pakistan. However, the percentage difference between girls and boys persisted. Only China and India were exceptions, where female fetuses are often deliberately aborted.

Causes are not clear
As the researchers continue to report, the miscarriage rate has hardly declined in the past 15 years. In industrialized countries, the cause remains unclear in about a quarter of miscarriages. Differences in placental function and a more sensitive reaction of male fetuses to factors such as obesity, smoking or a higher age of the mother are some of the suspected causes. Previous studies also found that taking anti-inflammatory drugs during pregnancy may increase the risk of miscarriage. The so-called non-steroidal anti-inflammatory drugs (NSAIDs) were mentioned, which also contribute to reducing fever and inhibit blood clotting. It has been known for some time that pregnancies with boys are obviously more complicated. Not only is the rate of miscarriages generally higher, but also premature births. (Ad)