During intrauterine life, some babies are smaller or grow less than expected. This fetal growth abnormality, called fetal growth restriction (FGR), can be diagnosed by ultrasound. Since there are currently no curative treatments for this condition, nor methods to optimize the growth of babies in the womb, the only effective strategy is intensive monitoring of fetal conditions, accompanied by early planning of delivery.

The diagnosis of early FGR (i.e. diagnosed before 32 weeks of gestation) confers a greater risk of short- and long-term respiratory problems.

The study aims to examine the association between parameters that can be assessed during pregnancy by ultrasound, such as the estimate of lung volumes, the thickness and contractility of the diaphragm, and cardiac kinetics, and any perinatal complications and respiratory function in the first years of life of premature infants, both with and without evidence of fetal growth pathology. Therefore, the study is divided into two phases: a prenatal and a postnatal phase.

The study includes two groups of patients:

1. Study group: Fetuses and preterm infants with a prenatal history of FGR;
2. Control group: Preterm infants without a prenatal history of FGR followed during neonatal follow-up.

Pregnant women with fetuses with FGR are followed at the Ultrasound clinics dedicated to Growth Pathology.

These pregnancies usually receive weekly ultrasound monitoring, which includes a Doppler study of the maternal and fetal circulation and an estimate of fetal weight every two weeks. Cardiotocographic monitoring is also planned once or twice a week, depending on fetal well-being.

The child will be assessed from a respiratory point of view during hospitalization and subsequently in the outpatient clinic, as required by clinical practice.

He/she will undergo respiratory function tests. Visits are scheduled at 3, 6, 12 and 24 months of corrected age, during which at least two respiratory function tests will be performed.

In addition, routine clinical data (personal data, medical history, blood tests, biological and instrumental tests) present in the medical record of the child will be collected.

Data from preterm infants without fetal growth restriction will be collected after informed consent. These infants are routinely followed at our Institution and undergo clinical assessment and lung function tests in the first two years of life as previously indicated.

Inclusion Criteria:

• Fetuses and Infants born before 32 weeks of gestation, with and without fetal growth restriction

Exclusion Criteria:

• Lack of informed consent
• Need for palliative care
• Major malformations

Fetuses and Infants born before 32 weeks of gestation, with and without fetal growth restriction