The aim of this study is to evaluate how variations in maternal nutrition may affect twin pregnancy and in particular:

• incidence of maternal obstetric complications:

  • gestational diabetes
  • gestational hypertension or preeclampsia
  • intrahepatic cholestasis (ICP)

• fetal growth, development and birth weight of the babies

Study design

At the time of recruitment, each patient will perform an initial clinical nutrition examination, during which will be evaluated, on the basis of BMI and specific anthropometric parameters, the necessary nutritional intake.

Patients included in the study will then be classified, on the basis of pre-pregnancy BMI, into 2 classes:

• normal weight (BMI 18-25)
• overweight (BMI 25-30) A specific diet will be developed for each patient, which will also take into account any food allergies or intolerances.

Each diet will be then eventually modified and revised throughout the pregnancy, according to the evolution of the same.

Patients will then continue their regular obstetrical examinations at the Obstetrical Day Hospital, every 4 weeks in case of uncomplicated dichorionic twin pregnancy and every 2 weeks in case of uncomplicated monochorionic twin pregnancy.

Once a month, in coincidence with the appointment at the Obstetric Day Hospital, the enrolled patients will be evaluated by the dedicated team of nutritionists.

Inclusion Criteria:

• dichorionic-diamniotic twin pregnancies
• monochorionic-diamniotic twin pregrancies
• monochorionic- monoamniotic twin pregnancies
• spontaneous onset or by homologous PMA techniques
• Age between 18 and 40 years
• Gestational age between 8 weeks+0 days and 25 weeks+6 days

Exclusion Criteria:

• Pregestational diabetes mellitus (type I and II)
• Chronic hypertension
• Previous bariatric surgery
• Chronic gastrointestinal disease (Celiac disease, Crohn's disease, Ulcerative Rectocolitis)
• Age less than 18 years or more than 40 years
• Gestational age less than 8 weeks or more than 26 weeks
• Fetal structural and/or genetic abnormalities
• Heterologous PMA
• Maternal eating disorders
• Drug and/or alcohol use
• Multiple pregnancies with more than two babies