A 33-year-old woman, gravida 7 para 6, at 39 weeks gestation undergoes induction of labor for new-onset hypertension. The patient became pregnant 5 months after her most recent delivery; otherwise, this pregnancy had been uncomplicated. Her previous pregnancies ended in uncomplicated term vaginal deliveries. She has a history of several lower uterine segment fibroids. Blood pressure is 160/96 mm Hg. Prepregnancy weight was 115 kg (253.5 lb) and the patient gained 13.6 kg (30 lb) during the pregnancy. Fundal height is 43 cm. Twenty-two hours after labor induction and after 2 hours of pushing, the fetal head delivers and retracts into the maternal perineum. Gentle traction fails to deliver the anterior fetal shoulder. Which of the following is the greatest risk factor for this patient's clinical presentation?

Question

A 33-year-old woman, gravida 7 para 6, at 39 weeks gestation undergoes induction of labor for new-onset hypertension.  The patient became pregnant 5 months after her most recent delivery; otherwise, this pregnancy had been uncomplicated.  Her previous pregnancies ended in uncomplicated term vaginal deliveries.  She has a history of several lower uterine segment fibroids.  Blood pressure is 160/96 mm Hg.  Prepregnancy weight was 115 kg (253.5 lb) and the patient gained 13.6 kg (30 lb) during the pregnancy.  Fundal height is 43 cm.  Twenty-two hours after labor induction and after 2 hours of pushing, the fetal head delivers and retracts into the maternal perineum.  Gentle traction fails to deliver the anterior fetal shoulder.  Which of the following is the greatest risk factor for this patient's clinical presentation?

Quizplus · Accepted Answer

11ec25c8_da85_7984_bc81_f7624ceba983_MD0003_00 Shoulder dystocia is the inability to deliver the fetal shoulders with usual obstetric maneuvers after the fetal head delivers. It is an obstetric emergency due to risk for neonatal brachial plexus injury, clavicular and humeral fracture, and, if prolonged, hypoxic brain injury and death. The major risk factor for shoulder dystocia is fetal macrosomia, defined as an estimated fetal weight >4.5 kg (9.9 lb). Other risk factors are conditions that predispose to macrosomia, including post-term pregnancy (>42 weeks gestation), maternal obesity, gestational diabetes mellitus, and excessive maternal weight gain during pregnancy. shoulder dystocia > Shoulder dystocia also frequently occurs in patients with no risk factors and can be difficult to predict. Warning signs of an impending dystocia include a prolonged first or second stage of labor and retraction of the fetal head into the perineum after delivery (eg, turtle sign). (Choice A) Post-term pregnancy is a risk factor for shoulder dystocia due to an increased risk of fetal macrosomia. This patient is at term. (Choices B and D) Hypertension and a short interpregnancy interval (eg, <18 months) are risk factors for fetal growth restriction rather than fetal macrosomia; consequently, they are not associated with shoulder dystocia. (Choice E) Uterine fibroids are associated with an increased risk for miscarriage, malpresentation, and cesarean delivery. Fibroids do not affect fetal growth and, therefore, do not increase the risk of shoulder dystocia. Educational objective: Shoulder dystocia is the inability to deliver the fetal shoulders with usual obstetric maneuvers. Warning signs include a prolonged first or second stage of labor and retraction of the fetal head into the perineum after it delivers (eg, turtle sign). Maternal obesity, which predisposes to fetal macrosomia, is an important risk factor. References: Shoulder dystocia: risk factors, predictability, and preventability. (http://www.ncbi.nlm.nih.gov/pubmed/24863023)

A 33-Year-Old Woman, Gravida 7 Para 6, at 39 Weeks