Yesterday I shared a Canadian article, and last year a letter from two OBs opposing a hospital VBAC ban, which discuss the risks of cesarean sections including placenta accreta and hysterectomy.
Today I want to share a study, but before I do so, lets do a quick review of definitions.
Placenta accreta (March of Dimes 2005):
In a normal pregnancy, the placenta attaches itself to the uterine wall, away from the cervix.
- Placenta accreta is a placenta that attaches itself too deeply and too firmly into the wall of the uterus.
- Placenta increta is a placenta that attaches itself even more deeply into the uterine wall.
- Placenta percreta is a placenta that attaches itself through the uterus, sometimes extending to nearby organs, such as the bladder.
These disorders occur in about 1 in 2,500 pregnancies. They often cause vaginal bleeding in the third trimester and often result in a premature delivery. Since the placenta cannot easily separate from the wall of the uterus after delivery, the placenta usually needs to be surgically removed. Often a hysterectomy (removal of the uterus) is necessary, although there are other surgical procedures that can be used to save the uterus.
Hysterectomy (Women’s Health 2009)
A hysterectomy (his-tur-EK-tuh-mee) is a surgery to remove a woman’s uterus or womb. The uterus is where a baby grows when a woman is pregnant. The whole uterus or just part of it may be removed. After a hysterectomy, you no longer have menstrual periods and cannot become pregnant.
During the hysterectomy, your doctor also may remove your fallopian tubes and ovaries. The ovaries produce eggs and hormones. The fallopian tubes carry eggs from the ovaries to the uterus. The cervix is the lower end of the uterus that joins the vagina.
Placenta previa (PubMedHealth 2011):
Placenta previa is a complication of pregnancy in which the placenta grows in the lowest part of the womb (uterus) and covers all or part of the opening to the cervix.
There are different forms of placenta previa:
- Marginal: The placenta is next to cervix but does not cover the opening.
- Partial: The placenta covers part of the cervical opening.
- Complete: The placenta covers all of the cervical opening.
Placenta previa occurs in 1 out of 200 pregnancies.
Today’s study is Maternal morbidity associated with multiple repeat cesarean deliveries (Silver 2006) which is a good sized study focusing on the risks of repeat cesareans and how those risks increase as the number of surgeries increase. This statement sums up their findings:
The risks of placenta accreta, cystotomy [surgical incision of the urinary bladder], bowel injury, ureteral [ureters are muscular ducts that propel urine from the kidneys to the urinary bladder] injury, and ileus [disruption of the normal propulsive gastrointestinal motor activity], 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.
Since I’m a visual person, I wanted to chart their findings because I think it makes the information easier to digest.
Remember as you look these over, the risk of uterine rupture in a spontaneous labor after one prior low horizontal (“bikini-cut”) cesarean is 0.4% (Landon 2004), which is lower than your risk of hysterectomy during your first cesarean (0.65%) and your risk of accreta during your third cesarean (0.57%). Risk of uterine rupture during one’s second cesarean is 0.9%. (Landon 2006)
Risk of Placenta Accreta & Hysterectomy by Cesarean Number
| CS | Accreta | Hysterectomy |
| 1st CS | 0.24% | 0.65% |
| 2nd CS | 0.31% | 0.42% |
| 3rd CS | 0.57% | 0.90% |
| 4th CS | 2.13% | 2.41% |
| 5th CS | 2.33% | 3.49% |
| 6th CS | 6.74% | 8.99% |
Risk of Placenta Accreta when Placenta Previa is Present by Cesarean Number
| # CS | Risk of accreta when previa is present |
| 1st CS | 3.00% |
| 2nd CS | 11.00% |
| 3rd CS | 40.00% |
| 4th CS | 61.00% |
| 5th CS | 67.00% |
Here is the study abstract:
Obstet Gynecol.2006 Jun;107(6):1226-32.
Maternal morbidity associated with multiple repeat cesarean deliveries.
Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, Moawad AH, Caritis SN, Harper M, Wapner RJ, Sorokin Y, Miodovnik M, Carpenter M, Peaceman AM, O’Sullivan MJ, Sibai B, Langer O, Thorp JM, Ramin SM, Mercer BM; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA. Bob.Silver@hsc.utah.edu
OBJECTIVE: Although repeat cesarean deliveries often are associated with serious morbidity, they account for only a portion of abdominal deliveries and are overlooked when evaluating morbidity. Our objective was 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. LEVEL OF EVIDENCE: II-2.
Last updated 1/9/12
Thankyou!!
We live in a world so afraid of birth. As the coordinator of the Australian support group of CARES-SA ( caesarean Awareness, recovery, education and support) http://www.cares-sa.org.au and a VBAC mum myself,and a GP, it is studies like these you can use, to show that an ” elective caesarean” is not the ” safest ” choice to have, which is what most OBs here – especially in the private health system really belive.
Great visuals! I would love to see those stats drawn all the way out to “no previous c/s” Because the risk is not zero, but heck of a lot less than after even 1 cesarean! Because it is key to prevent that first one! Thanks again for all your dedication!
Great post. I especially love the last line of the abstract where they recommend this data as part of the debate prior to primary elective cesarean. Of note is that in the definition for placenta accreta the rate is 1 in 2,500, but in the study the rate was 1 in 416 for women undergoing their first cesarean. That is a very scary number, and one I’m not too sure of. I wonder if the setting had anything to do with it. Either way, these are important risks which need to be discussed. Thanks!
[...] Maternal morbidity associated with multiple repeat cesarean deliveries. [...]
Hi. We’d love to publish this article in our newsletter for CARES-SA in Australia. We only do about 60 copies. Please advise if we can use this article
Many thanks
Michelle
Michelle,
I would love that! Could you mail me a copy? I’ll email you privately with an address!
Warmly,
Jen
I was recently given the article to read from McMaster University in Hamilton, Ontario, Canada. As I am considering having my 6th cs. This was never an elective surgery for me, my 1st pregnancy I went 1 mth overdue and was induced. To this day I have never even had a contraction, no doctor has even been able to explain to me why. This article is the only information that doctors were even able to give me to help me make this decision. I want to have more children and wish there was another way. I also know that if I do choose to have another one that I should not try again after this one. I have had no serious problems in the past with my surgeries, the last my bladder moved and they had to cut it away and put it back. Scarring is always excessive which is expected and the doctor always cleans it up as much as possible. I want to know where I can find more information before I make this big decision. I am 39 years old, extremely healthy and in great shape, I work out at least 3 times a week. I have never seen any of the studies describing any of the patients. I have always concentrated on recovery and doing all I can to make sure my recovery is successful and trying to build my muscles back up again. Overall my thoughts after reading the study….it is a bit confusing as you do need to figure out the percentages separately as it is misleading when looking at the number of CS. What I am also gathering is that most of the injuries that can happen can be fixed and are not life threatening. I will be going back to my gynecologist and discussing this article with her and checking to see that the hospital in my area can even deal with the problems that may arise at time of delivery if I do decide to do this, whether the blood bank is there, other operatable staff is available etc. So many factors to decide, it would be easier if they had installed a zipper. If anyone has more information that can help me with this serious decision, it would be greatly appreciated.
[...] to miscarriages and may experience a delay in future conception. The scar tissue can later become the site of a future baby’s placenta, creating a condition that can be life threatening for Mom. If the placenta imbeds itself deeply into the scar tissue inside the uterus, it can be difficult [...]
I have had 4 C-sections in my life time. After that delivered VBack. When I was having babies there were no doctors that would allow me to have a normal delivery. It was not until I found a brave midwife who would help me and allow me to do a VBack. I am so thankful for her and my wonderful husband who helped me accomplish that task. The Lord has been so good to me to have kept me alive and with out major complications from my C’s.
I delivered my last baby at the age of 45. I try hard to encourage all I know who have had C’s to do all they can to go VBack. My daughter just had a VB and was so amazing with her determination to complete the process. She and the baby are both Strong and healthy. It can be done and it is so much safer for both Mom and baby. I am glad all this information has been offered. I hope more will read it and know that VBacks are totally possible, and a much healthier choice.