1) Study 1:

Obstetrics & Gynecology
(2008;111:285-291).

The study's OBJECTIVE: To estimate the success rates and risks of an
attempted vaginal birth after cesarean delivery (VBAC) according to the
number of prior successful VBACs.

METHODS: From a prospective multicenter registry collected at 19 clinical
centers from 1999 to 2002, we selected women with one or more prior low
transverse cesarean deliveries who attempted a VBAC in the current
pregnancy. Outcomes were compared according to the number of prior VBAC
attempts subsequent to the last cesarean delivery.

RESULTS: Among 13,532 women meeting eligibility criteria, VBAC success
increased with increasing number of prior VBACs: 63.3%, 87.6%, 90.9%, 90.6%,
and 91.6% for those with 0, 1, 2, 3, and 4 or more prior VBACs, respectively
(P<.001). The rate of uterine rupture decreased after the first successful
VBAC and did not increase thereafter: 0.87%, 0.45%, 0.38%, 0.54%,
0.52%(P=.03). The risk of uterine dehiscence and other peripartum
complications
also declined statistically after the first successful VBAC. No increase in
neonatal morbidities was seen with increasing VBAC number thereafter.

CONCLUSION: Women with prior successful VBAC attempts are at low risk for
maternal and neonatal complications during subsequent VBAC attempts. An
increasing number of prior VBACs is associated with a greater probability of
VBAC success, as well as a lower risk of uterine rupture and perinatal
complications in the current pregnancy.

2) Study 2:

Contrast that study with another from Obstetrics & Gynecology
(2006;107:1226-1232) which found that there is maternal morbidity associated
with multiple repeat cesareans.

OBJECTIVE: To estimate the magnitude of increased maternal morbidity
associated with increasing number of cesarean deliveries.

METHODS: Prospective observational cohort of 30,132 women who had cesarean
delivery without labor in 19 academic centers over 4 years (1999–2002).

RESULTS: There were 6,201 first (primary), 15,808 second, 6,324 third, 1,452
fourth, 258 fifth, and 89 sixth or more cesarean deliveries. The risks of
placenta accreta, cystotomy, bowel injury, ureteral injury, and ileus, the
need for postoperative ventilation, intensive care unit admission,
hysterectomy, and blood transfusion requiring 4 or more units, and the
duration of operative time and hospital stay *significantly increased *with
increasing number of cesarean deliveries. Placenta accreta was present in 15
(0.24%), 49 (0.31%), 36 (0.57%), 31 (2.13%), 6 (2.33%), and 6 (6.74%) women
undergoing their first, second, third, fourth, fifth, and sixth or more
cesarean deliveries, respectively. Hysterectomy was required in 40 (0.65%)
first, 67 (0.42%) second, 57 (0.90%) third, 35 (2.41%) fourth, 9 (3.49%)
fifth, and 8 (8.99%) sixth or more cesarean deliveries. In the 723 women
with previa, the risk for placenta accreta was 3%, 11%, 40%, 61%, and 67%
for first, second, third, fourth, and fifth or more repeat cesarean
deliveries, respectively.

CONCLUSION: Because serious maternal morbidity increases progressively with
increasing number of cesarean deliveries, the number of intended pregnancies
should be considered during counseling regarding elective repeat cesarean
operation versus a trial of labor and when debating the merits of elective
primary cesarean delivery.

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Cesarean Rate Hits a New High Recent Studies Show Cesareans Can Pose Dangers to Mothers and Babies Release Highlights: Cesarean rate at record high in the U.S. Cesarean rise coincides with CDC report that maternal death rate rising for the            first time in decades. World Health Organization data shows that mothers die at a higher rate in the            U.S. than 40 other countries. Consumer Reports includes cesarean on “10 overused tests and treatments” Redondo Beach, CA, December 5, 2007 – The National Center for Health Statistics has reported that the cesarean rate has hit an all-time high of 31.1 percent. CDC's Peliminary Data for 2006 “There’s no doubt that cesarean surgery is being overused,” said Pam Udy, president of the International Cesarean Awareness Network. “Unfortunately, despite its reputation as a harmless surgery, many women and babies are paying the high price of complications from this surgery.” Read more...

Rising Cesarean Rate Bad for Mothers Top 12 Studies from 2007 Maternal and neonatal individual risks and benefits associated with caesarean delivery: multicentre prospective study (Villar, et al., British Medical Journal, 2007;335:1025, 17 November) Study Design: Researchers assessed the risks and benefits of cesarean delivery vs. vaginal delivery. Bottom line: Cesarean carries twice the risk of injury and death for both mother and baby. Women with cesarean experience double the rate of hysterectomy, blood transfusion, admission to intensive care, prolonged hospital stay and death, compared to mother who delivered vaginally. Babies born by cesarean were 45 percent more likely to be in the neonatal intensive care unit for 7 days and 41-82 percent more likely to die than babies born vaginally. Risk of Uterine Rupture and Adverse Perinatal Outcome at Term After Cesarean Delivery (Spong, et al., Obstetrics and Gynecology 2007; 110: 801-7) Study Design: Researchers examined the risk of uterine rupture after cesarean and what harms it may have for mothers and babies. Bottom line: Regardless of how the baby was delivered, the rate of uterine rupture was low and complications from rupture were also low for both mother and baby. Read more...