Association of Fetal Abdominal-Head Circumference Size Difference With Shoulder Dystocia: A Multicenter Study.
Objective This study aims to determine if shoulder dystocia is associated with a difference in the fetal abdominal (AC) to head circumference (HC) of 50 mm or more noted on antenatal ultrasound. Study Design A multicenter matched case-control study was performed comparing women who had shoulder dystocia to controls who did not. Women with vaginal births of live born nonanomalous singletons ≥ 36 weeks of gestation with an antenatal ultrasound within 4 weeks of delivery were included. Controls were matched for gestational age, route of delivery, and diabetes status. Results We identified 181 matched pairs. Only 5% of the fetuses had an AC to HC of ≥ 50 mm. The proportion of AC to HC difference of ≥ 50 mm was significantly higher in shoulder dystocia cases (8%) than controls (1%, p = 0.002). With multivariate regression, the three significant factors associated with shoulder dystocia were AC to HC ≥ 50 mm (odds ratio [OR], 7.3; confidence interval [CI], 1.6-33.3; p = 0.010), femur length (OR, 1.1; CI, 1.0-1.2; p = 0.002), and induced labor (OR, 1.8; CI, 1.1-3.1; p = 0.027). Conclusion A prenatal ultrasound finding of a difference in AC to HC of ≥ 50 mm while uncommon is associated with shoulder dystocia.
Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Center for Biomedical and Research Informatics, Evanston, Illinois.
Loraine
L
Endres
Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, Ohio.
Emily
E
DeFranco
Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Center for Biomedical and Research Informatics, Evanston, Illinois.
Theresa
T
Conyac
Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Center for Biomedical and Research Informatics, Evanston, Illinois.
Marci
M
Adams
Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Center for Biomedical and Research Informatics, Evanston, Illinois.
Ying
Y
Zhou
Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, Ohio.
Kristin
K
Magner
Department of Obstetrics and Gynecology, Aurora Sinai Medical Center, Milwaukee, Wisconsin.
Luke
L
O'Rourke
Department of Obstetrics and Gynecology, Aurora Sinai Medical Center, Milwaukee, Wisconsin.
Kiley A
KA
Bernhard
Department of Obstetrics and Gynecology, Aurora Sinai Medical Center, Milwaukee, Wisconsin.
Danish
D
Siddiqui
Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, Illinois.
Anna
A
McCormick
Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, Illinois.
Jacques
J
Abramowicz
Good Samaritan Hospital, Fetal Care Center of Cincinnati, Cincinnati, Ohio.
Ronald
R
Merkel
Good Samaritan Hospital, Fetal Care Center of Cincinnati, Cincinnati, Ohio.
Rana
R
Jawish
Good Samaritan Hospital, Fetal Care Center of Cincinnati, Cincinnati, Ohio.
Mounira
M
Habli
Department of Obstetrics and Gynecology, University of Arkansas Medical School, Little Rock, Arkansas.
Alissa
A
Floman
Department of Obstetrics and Gynecology, University of Arkansas Medical School, Little Rock, Arkansas.
Everett F
EF
Magann
Department of Obstetrics, Gynecology and Reproductive Sciences, Lyndon B. Johnson Hospital, Houston, Texas.
Suneet P
SP
Chauhan
abdominal circumference; head circumference; shoulder dystocia; ultrasound