If you're the second twin, just thank God you're alive!

Because a nine-year British research, conducted between 1994 and 2003, found that being a second born twin means a slightly higher risk of dying from fatal complications during birth.

Twins born preterm (before 36 weeks) have no difference in the overall death level between the first and second, as they are already exposed to a higher risk by prematurity.

But the second twin born at or after the full term of pregnancy (36 weeks and more) presented a double risk of dying during or shortly after birth, due to complications inflicted by labor.

Some researches had already pointed out that second born twins present higher levels of mortality compared to their elder brothers, while other surveys had not found discernible impact on the twin's chance of survival.

The new complex research made an ample analysis of all twin pregnancies with one death during or shortly after the delivery in England, Northern Ireland and Wales, employing official data recording twin deaths since the early 1990s, including the Confidential Enquiry into Maternal and Child Health (CEMACH), the Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI) and Office for National Statistics (ONS).

The researchers meticulously screened each case to eliminate any factor not related with the labor inducing the death, that would shift the final results of the analysis, like for example malformations or therapeutic abortions.

1377 entered in the analysis pool to identify the link between birth order and the risk of death.

Additional factors were also included in the analysis to check if they biased the connection between birth order and the risk of death, like the length of gestation, delivery method, mother's age and ethnicity and others.

The was no link between birth order and the overall risk of death for preterm twins; mother's age and ethnic group also did not bias in any way the twins' mortality.

But analysis showed that the second twins born at term had a more than double risk of death during or shortly after the delivery, due to complications inflicted by the labor.

In case of cesarean section, this risk was found largely decreased, but further investigation is required to conclusively prove this.