The duration of a full term pregnancy is 41 weeks of amenorrhea (39 weeks of pregnancy), but we speak of preterm delivery only before 37 weeks (35 weeks of pregnancy). There are also three levels of prematurity:

• average prematurity for childbirth occurring between 33 WA and 36 WA + 6 days (7 to 8 months of pregnancy);
• extreme prematurity for a birth between 28 to 32 WA + 6 days (ie 6 to 7 months of pregnancy);
• very great prematurity for a birth occurring before 28 weeks (6 months of pregnancy).

Before 25 weeks, survival remains rare. In France, no intervention is attempted on premature babies born before 23 weeks of pregnancy.

As in all developed countries, we observe in France an increase in premature births, going from 5,9% of births in 1995 to 7,4% in 2010. Each year, 60 children are born prematurely, 000% of which are premature. medium, 85% very premature and 10% very premature (5).

It concerns around 60% of premature births (2). Labor begins spontaneously due to early contractions or premature rupture of membranes (water bag), often following a bacterial infection. This labor may be preceded by a threat of premature delivery (PAD) characterized by regular uterine contractions associated with a modified cervix (cervix less than 25 mm on vaginal examination or endovaginal ultrasound). In the event of PAD, the mother is usually hospitalized in order to find the cause of the early contractions and if possible treat it. To know :

• urinary tract infection;
• infection of the cervix or vagina;
• generalized infection (influenza, rubella, toxoplasmosis, listeriosis);
• a uterine malformation;
• an open neck;
• placental insertion abnormalities;
• a violent shock to the uterus;
• multiple pregnancy.

Sometimes, however, no cause is found. The mechanism of contractions and the start of childbirth is not yet fully understood.

In the event of PAD, the mother-to-be is put to rest and a treatment intended to stop the contractions possibly administered, knowing however that it is impossible to stop a childbirth which has just started. Depending on the severity of the threat, hospitalization is sometimes necessary. It will be done depending on the term in a level II or III maternity in order to ensure the proper care of the baby if it were to be born. In the event of a severe threat, corticosteroids are given to the mother to speed up the baby’s lung maturation and reduce his risk of cerebral hemorrhage.

In 40% of cases, it is an induced prematurity: the medical team decides to deliver the baby earlier, most often by cesarean section, because the health or even the survival of the fetus or mother is in danger. following a pregnancy complication:

• severe arterial hypertension and its complications (preeclampsia, eclampsia, liver problems, destruction of red blood cells and blood platelets). Severe maternal hypertension represents 20% of the reasons for giving birth with 32 weeks (3);
• maternal bleeding due to a complication of placenta previa or retro-placental hematoma;
• unstable gestational diabetes;
• severe in utero growth retardation (IUGR);
• fetal distress, especially in the event of multiple pregnancy.

The baby’s organs are quickly in place but their development continues throughout the pregnancy. Prematurity therefore interrupts this maturation process. Despite progress in neonatal care, prematurity – especially the very great – remains a risk situation, starting with the survival of the baby. According to Epipage 2, a study bringing together nearly 7000 children to assess the survival of premature infants born between 22 and 34 WA and their subsequent outcome, survival reached 99% at 32-34 WA, 94% at 27-31 WA, but only 60% at 25 SA and less than 1% before 24 SA. However, these results show a clear improvement since 1997 and the results of Epipage 1 (4).

Also according to Epipage 2, the survival rate without serious neonatal pathology is 97% at 32-34 WA, 81% at 27-31 WA, but only 30% at 25 WA and 12% at 24 WA. All the baby’s functions are concerned: thermoregulation, cardiac, pulmonary, digestive, renal, cerebral, immune function, etc. neonatal intensive care unit, intensive care unit or neonatal unit. The management is multiple: incubation, respiratory assistance, administration of various treatments (surfactant in particular to compensate for pulmonary immaturity) by intubation tube, enteral feeding (systematic before 34 weeks), phototherapy to treat the jaundice, etc. In this ultra-medicalized world, parents also have an essential role to play because the newborn, even premature, is a small being endowed with all his senses. The “skin to skin” or “kangaroo method”, practiced today in many neonatal units, helps to promote the bond between the baby and his parents but also presents, according to a study published in Biological Psychiatry (5), long-term benefits in children: an attenuated stress response, more mature autonomic functioning, better organized sleep and better learning abilities.

In the long term, the risks of neurological sequelae are frequent, especially in very premature babies. They can result in motor and / or cognitive disorders. According to Epipage 2, the risk of intellectual disability is 15% for very premature babies, 10% for average premature babies and 5% for late prematurity. At the motor level, the risk of motor handicap is 10% for very premature babies, 4% for moderate premature babies and 0,5% for late prematurity.

Premature childbirth is always a shock to parents, especially if it was totally unexpected. Different feelings are superimposed on the joy of being a parent: the fear that surrounds the first weeks or even months of a premature baby’s life, anger, the feeling of injustice, and sometimes a feeling of guilt – obviously unfounded – in some people. moms who may feel they haven’t been able to “keep” their babies safe in their wombs. Support groups organized in certain neonatal departments and associations (6) are invaluable psychological help in overcoming this ordeal of prematurity.

Above all, it involves monitoring pregnancy, the objective of which is to detect at an early stage any complications (IUGR, hypertension, etc.) liable to lead to premature childbirth. This monitoring also aims to identify situations identified as at risk of prematurity: an underprivileged environment, a low level of education of the mother, difficulty at work, a young or high maternal age, the fact of living alone, high parity, pathologic obstetric history (7).

In addition, much work is underway to try to understand the different mechanisms at the origin of prematurity. They relate in particular to the placenta, the idea being to find blood markers allowing earlier diagnosis of its dysfunctions which can lead to premature delivery. The track of maternal infections is also the subject of many studies.