**Question:** Hazard of chorionic villous biopsy is:

A. Increased risk of maternal complications
B. Increased risk of fetal complications
C. Increased risk of placental insufficiency
D. Increased risk of fetal loss

**Core Concept:**

Chorionic villous biopsy is a diagnostic procedure performed during pregnancy to obtain placental tissue for genetic testing, such as karyotyping or microarray analysis. This procedure aims to identify chromosomal or genetic abnormalities in the fetus. The biopsy involves cutting out samples from the chorionic villi, which are small projections from the placental villi that grow into the maternal uterine wall.

**Why the Correct Answer is Right:**

The correct answer is D. Increased risk of fetal loss. Chorionic villous biopsy carries a potential risk for the fetus due to the invasive nature of the procedure. Although the procedure is minimally invasive, complications can occur, leading to:

1. Increased risk of fetal loss: The procedure may cause premature labor, premature rupture of membranes, or placental abruption leading to fetal demise.

2. Increased risk of fetal injury: The procedure can result in placental abruption, leading to bleeding, uterine rupture, or sepsis in the fetus.

3. Increased risk of maternal complications: Although rare, chorionic villous biopsy carries a very low risk of maternal complications such as uterine rupture, sepsis, or hemorrhage.

**Why Each Wrong Option is Incorrect:**

A. Increased risk of maternal complications (Correct, as mentioned above)
B. Increased risk of fetal complications (Incorrect) - The main risk lies in the procedure's potential to cause fetal loss or injury.
C. Increased risk of placental insufficiency (Incorrect) - Placental insufficiency is not a direct consequence of chorionic villous biopsy but rather a potential complication of the procedure.

**Clinical Pearl:**

While chorionic villous biopsy is a valuable diagnostic tool for detecting genetic abnormalities, it is essential to weigh the potential risks against the potential benefits for the individual case. Alternative non-invasive prenatal testing methods, such as non-invasive prenatal testing (NIPT), are increasingly being used for detecting chromosomal abnormalities due to their lower risk profile. Consultation with a genetic counselor is essential prior to proceeding with invasive testing like chorionic villous biopsy.