Overweight is a condition that affects health throughout the lifespan, and it is well-established that excessive weight gain in pregnancy is associated with complications such as gestational diabetes and pre-eclampsia in the mother. A 2008 study published in Acta Obstet Gynecol Scandia by MUSC researchers demonstrates that overweight pregnant women have a higher rate of other complications of pregnancy: so-called “shoulder dystocia,” as well as an increased rate of Caesarean section delivery.
Researchers in this study included Drs. Roger Newman and Tom Hulsey in the College of Medicine and Tara Hulsey of the College of Nursing. They followed 6,949 women between 1994-2004 and documented that a Body Mass Index (BMI) greater rather 30 was associated with an increased rate of Caesarean section. The population risk for caesarean section due to dystocia, attributable to BMI greater than 35 in low risk pregnancies, was 13.3%.
Shoulder dystocia is more common in large babies, which is why excessive weight gain during pregnancy may lead to dystocia. It is one of the most frightening obstetrical emergencies and occurs when the baby’s shoulder impacts on the pelvic anatomy of the mother, suddenly halting the progress of delivery and leading to lowered oxygen supply for the infant and potential neurological injury or stillbirth. The obstetrican will typically try to maneuver the infant into a more favorable position for delivery, but these same maneuvers can result in birth trauma such as fractured bones or nerve damage leading to paralysis of the arm.
Roman Horace; Goffinet Francois; Hulsey Tara F; Newman Roger; Robillard Pierre Yves; Hulsey Thomas C
Maternal body mass index at delivery and risk of caesarean due to dystocia in low risk pregnancies.
Acta obstetricia et gynecologica Scandinavica. 2008;87(2):163-70.