Very premature infants: viability threshold decreases by one week every 10 years

Over the last 30 years, scientific advances in developed countries have saved more and more premature babies. In particular, infants born within six months of pregnancy.

A baby is considered to be premature when born before 37 weeks of pregnancy. Since the 1980s, global medicine has made many advances to save those who are extremely premature. Several studies, published this week and conducted in the United States and Sweden, bear witness to this.

The viability threshold "declines by one week every 10 years"

Until the 1980s, it was estimated that the minimum gestational age for viability was 28 weeks. At this point, the baby weighs only 1,000 grams. Today, babies survive at 24, 23 or even 22 weeks and weigh about 500 grams only! "I've been doing this job for 40 years, and I've seen the viability threshold go back a week every 10 years in my hospital," says Edward Bell, Neonatal Physician and Pediatric Professor at the University of Iowa. (United States).

Sweden, world champion of survival

In Sweden, 77% of children born between 22 and 26 weeks survived at least one year, according to a study conducted between 2014 and 2016 and published in the journal Jama. Ten years earlier, between 2004 and 2007, this survival rate in Sweden was "only" 70%. Before setting the world record for survival of extremely premature babies, Sweden has introduced new procedures, such as systematic resuscitation of newborns. Today, about 88% of premature deliveries are in specialized units.

3 advances to save lives

In hospitals around the world - particularly developed countries - three major advances have helped advance the survival rate of extremely premature babies. First, the invention of artificial "surfactants", which make it possible to replace a substance that very premature babies do not produce on their own. The latter occurs in the lungs and allows them to breathe. Secondly, doctors now inject steroids to the mother just before giving birth, allowing the baby's lungs to develop a week in a day. Finally, breathing apparatuses have become more efficient over the years.

Babies under 400 grams

These advances can improve the survival of premature babies, even babies under 400 grams, which are very rare. So, an American study published Monday in the journal Jama shows that 13% of babies under 400 grams born at 22-26 weeks survived. The study covers 21 hospitals and was conducted between 2008 and 2016. One of these babies weighed even 330 grams. Note that in the case of these infants, complications can be many, such as a developmental delay of two years. Every year in France, around 60,000 babies are born before term.

Video: EMT 5-11: Obstetrics and Gynecology (November 2019).