Fetal anomalies are structural and/or functional disorders of the fetus (the baby in the womb). Anomalies can occur in any system of the fetus, and the causes vary by region.
Regions where anomalies can occur:

  • Central nervous system,
  • Neck and face,
  • Heart,
  • Respiratory system,
  • Abdominal wall and abdominal cavities, and the digestive system of the fetus,
  • Urinary system,
  • Genital system,
  • Extremities (arms and legs),
  • Placenta and umbilical cord.

With today's ultrasound technology, fetal anomalies can be detected in the early months of pregnancy. Detailed ultrasound examination of the fetus and screening for anomalies in the 20th to 23rd week of pregnancy are particularly important:

  • In some anomalies, the fetus has no chance of survival after birth or severe sequelae may occur, and the family may be offered the option of abortion.
  • For other treatable or controllable anomalies, a normal or near-normal life may be possible with treatment both in utero during pregnancy and immediately after birth.


How do congenital anomalies develop?

Fetal anomalies can develop in several ways:

  • Fetal congenital anomalies can result from chromosomal or genetic defects. These defects can develop because of inherited traits from the mother or father, or because of problems with cell division after fertilization.
  • Some fetal anomalies are more common in certain ethnic groups, such as certain blood disorders and cystic fibrosis.
  • There are fetal anomalies that develop after fertilization through the fusion of the egg and sperm and subsequent cell stages: Down syndrome (trisomy 21), Edwards syndrome (trisomy 18).
  • Anomalies can occur as a result of substance abuse (smoking, alcohol, cocaine, etc.).


Preferably, fetal congenital anomaly screening is performed in 2 stages:

  • Early detailed fetal ultrasound and genetic screening tests are performed from 11-14 weeks of gestation.
  • Thereafter, detailed fetal ultrasonography, preferably at 20-23 weeks of gestation, is the primary method for detecting anomalies.
  • Nevertheless, after all screening tests and ultrasound examinations, only about 90% of major anomalies and about 80% of minor anomalies can be detected during pregnancy.

Although screening is currently recommended for all pregnant women, the final decision rests with the families themselves. However, screening should definitely be recommended for patients with a history of medical risk:

  • Advanced gestational age (> 35 years),
  • Patients with diabetes prior to pregnancy,
  • Congenital anomalies in a close relative, the expectant mother or father,
  • Chromosomal anomaly in a close relative, the expectant mother or father,
  • Metabolic diseases in the family that increase the risk of anomalies,
  • Exposure to environmental agents and teratogens (agents that can cause anomalies): Radiation or drugs that can affect pregnancy,
  • Overweight expectant mother (increased BMI),
  • Multiple pregnancies, especially identical twins,
  • IVF (in vitro fertilization) pregnancies,
  • Abnormal birth or abortion in previous pregnancies.


Prof. Dr. Ali Gedikbaşı
Contact Information

+90 545 213 5140 - Appointment

Fulya Terrace Center 1
Kat 8 Daire 31,
Hakkı Yeten Caddesi No 11,
Fulya-Şişli, İstanbul

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