Breech presentation

Breech presentation is a normal finding in preterm pregnancies, when the fetus is more mobile, and should not be considered abnormal until late pregnancy. Knowledge of the fetal presentation is important at the time of delivery (regardless of gestation) and prior to delivery as the pregnancy approaches term because this is when external cephalic version becomes an option. Diagnosis after the onset of labor is associated with increased maternal and infant morbidity and mortality.[23]Waterstone M, Bewley S, Wolfe C. Incidence and predictors of severe obstetric morbidity: case-control study. BMJ. 2001 May 5;322(7294):1089-93. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC31259 http://www.ncbi.nlm.nih.gov/pubmed/11337436?tool=bestpractice.com

History

History of pregnancy events should be obtained including recent symptoms, parity, and previous modes of delivery. Confirmation of the last menstrual period and of the gestation will highlight risk factors of prematurity and a small for gestational age fetus. In addition, history should be reviewed for vaginal bleeding indicative of risk factors such as placenta previa because they can complicate management.​​ Symptoms of specific pain or tenderness under one or other costal margin could be a result of pressure by the harder fetal head. There may be a history of pain due to fetal kicks in the maternal pelvis or bladder.

Clinical exam

Fetal presentation should be assessed using clinical examination at each prenatal visit in late second and third trimesters. The Leopold maneuver is an important diagnostic step in late second trimester and consists of four distinct stages:[1]Cunningham F, Gant N, Leveno K, et al. Williams obstetrics. 21st ed. New York: McGraw-Hill; 1997.

• Palpation of the abdomen to determine the position of the baby's head

• Palpation of the abdomen to confirm the position of the fetal spine on one side and fetal extremities on the other

• Palpation of the area above the symphysis pubis to locate the fetal presenting part

• Palpation of the presenting part to confirm presentation, to determine how far the fetus has descended and whether the fetus is engaged.

The sensitivity and specificity of diagnosing breech presentation at 35 to 37 weeks' gestation by clinical examination are 70% and 95%, and the positive and negative predictive value are 55% and 97%.[4]Nassar N, Roberts CL, Cameron CA, et al. Diagnostic accuracy of clinical examination for detection of non-cephalic presentation in late pregnancy: cross sectional analytic study. BMJ. 2006 Sep 16;333(7568):578-80. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1570002 http://www.ncbi.nlm.nih.gov/pubmed/16891327?tool=bestpractice.com

The position of the fetus is further confirmed by locating the fetal heartbeat using a Pinard stethoscope or a hand-held Doppler. A fetal heartbeat above the maternal umbilicus suggests a breech presentation.[1]Cunningham F, Gant N, Leveno K, et al. Williams obstetrics. 21st ed. New York: McGraw-Hill; 1997.

Pelvic examination (including vaginal speculum and/or digital) further helps identify the presenting part; the fetal head is hard and round and the breech is a softer, yielding irregular mass.[1]Cunningham F, Gant N, Leveno K, et al. Williams obstetrics. 21st ed. New York: McGraw-Hill; 1997.[24]Beischer NA, Mackay EV, Colditz P, eds. Obstetrics and the newborn: an illustrated textbook. 3rd ed. London: W.B. Saunders; 1997. Vaginal examination, using an aseptic technique, should establish the type of breech presentation, the position of the fetal sacrum, and the station of the breech. Cord prolapse and nuchal cord is more common with breech presentation and a careful assessment to exclude the presence of any loops of umbilical cord should be made.[25]Impey LWM, Murphy DJ, Griffiths M, et al; Royal College of Obstetricians and Gynaecologists. Management of breech presentation: green-top guideline no. 20b. BJOG. 2017 Jun;124(7):e151-77. http://onlinelibrary.wiley.com/doi/10.1111/1471-0528.14465/epdf http://www.ncbi.nlm.nih.gov/pubmed/28299904?tool=bestpractice.com Digital examination should not be performed if there is any suspicion of placenta previa.[26]Royal College of Obstetricians and Gynaecologists. Antepartum haemorrhage: green–top guideline no. 63. November 2011 [internet publication]. https://www.rcog.org.uk/globalassets/documents/guidelines/gtg_63.pdf

Ultrasound examination

A transabdominal or transvaginal ultrasound will confirm the diagnosis of breech presentation and should be performed by practitioners with appropriate skills in obstetric ultrasound.[27]American College of Obstetricians and Gynecologists. Practice bulletin no. 175: ultrasound in pregnancy. Obstet Gynecol. 2016 Dec;128(6):e241-56. http://www.ncbi.nlm.nih.gov/pubmed/27875472?tool=bestpractice.com ​ A transabdominal ultrasound can also establish the type of breech presentation by imaging the fetal femurs and their relationship to distal bones. It is important to exclude any causative factors (e.g., polyhydramnios, low-lying placenta, fetal anomaly) that may influence the management decisions and mode of delivery.