Why Do Most Miscarriages Happen in the First Trimester?

According to the Brazilian Federation of Gynecology and Obstetrics (Febrasgo), 80% of pregnancy losses occur in the first trimester. Obstetrician and gynecologist Paulo Noronha explains that this is because the first trimester is a period of intense embryonic formation and development. When something prevents that development from continuing normally, the body may interrupt the pregnancy.

What Did the Couple Share Publicly?

Brazilian surf champion Gabriel Medina announced on Tuesday, August 4, that his wife Isabella Arantes had lost the baby they were expecting. The loss was discovered during a first-trimester morphological ultrasound, which showed the pregnancy had not progressed to the fetal stage. The news came just five days after the couple's wedding, at which Medina had revealed he would become a father.

On Instagram Stories, Medina shared a message of hope featuring the phrase "Have faith, don't rush." Isabella also posted a reflective message, writing: "Our hearts need time. We are living days of silence, healing and trust in God. We have felt His love sustaining and comforting us." She asked followers for understanding and respect during this difficult period.

Should Mothers Feel Guilty After a Miscarriage?

Many pregnant women feel guilty after a miscarriage, but specialists emphasise that in most cases it is unavoidable. Dr. Noronha notes that early pregnancy loss is relatively common from a medical standpoint and that most first-trimester miscarriages result from chromosomal abnormalities in the embryo — something outside anyone's control.

What Is a Morphological Ultrasound?

A first-trimester morphological ultrasound is a routine prenatal exam, usually performed between weeks 11 and 14, that assesses embryonic development and screens for structural issues. It is during this exam that some unviable pregnancies are first detected, often before any physical symptoms appear.

Key Facts:
  • Gabriel Medina and Isabella Arantes announced a miscarriage on 4 August 2026.
  • The loss was detected during a first-trimester morphological ultrasound.
  • The news came five days after their wedding.
  • Febrasgo reports that 80% of pregnancy losses occur in the first trimester.
  • Most early miscarriages are caused by chromosomal abnormalities and are not preventable.