FMGE 2023 — Obstetrics and Gynecology

Q: Which of the following is the process of breaking the clavicle during delivery?

Cleidotomy. ***Cleidotomy*** - This is a destructive obstetric procedure where the fetal clavicle is intentionally broken or cut to reduce the **bisacromial diameter**. It is utilized primarily in cases of severe, unrelieved **shoulder dystocia**, especially if the fetus has already succumbed (**Fetal demise**). *Craniotomy* - This is a destructive procedure aimed at reducing the size of the **fetal head** by crushing or perforating the skull. It is performed when the fetal head is impacted and delivery is otherwise impossible, usually only if there is **fetal demise**. *Symphysiotomy* - This procedure involves surgically incising the **fibrocartilage** of the **pubic symphysis** to widen the pelvic outlet. It is used to relieve **obstructed labor** due to minor cephalopelvic disproportion, allowing vaginal delivery. *Zavanelli manoeuvre* - This is an emergency procedure for severe **shoulder dystocia** where the delivered fetal head is pushed back into the birth canal (**cephalic replacement**). It mandates immediate delivery via **Cesarean section** following the replacement.

Q: Which of the following is the best parameter for estimation of fetal age by ultrasound in 1st trimester?

Crown rump length. ***Crown rump length*** - The **Crown Rump Length (CRL)** is the most accurate parameter for estimating gestational age during the **first trimester** (up to 12 weeks of gestation). - This is because biological variation between fetuses is minimal during early development, providing a narrow range of error (typically ±5-7 days). *Biparietal Diameter* - **Biparietal Diameter (BPD)** becomes the primary parameter for dating in the **second trimester** (after 12 weeks of gestation). - Its accuracy in the first trimester is significantly lower than CRL due to difficulty in obtaining standardized measurements and higher potential for measurement variability. *Head circumference* - **Head circumference (HC)** is highly utilized, often alongside BPD, for fetal growth assessment and dating near the mid-to-late second trimester. - Like BPD, HC is not the most precise measure for dating during the **first trimester** when CRL dominates. *Abdominal circumference* - **Abdominal circumference (AC)** is mainly used to assess **fetal weight** and growth, often becoming inaccurate for dating due to high biological variability later in gestation. - It is the least accurate parameter for establishing gestational age in the **first trimester** compared to CRL, BPD, and HC.

22 Questions — Page 3 of 3

Q21

Which of the following is the process of breaking the clavicle during delivery?

Q22

Which of the following is the best parameter for estimation of fetal age by ultrasound in 1st trimester?