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Research and Evidence
Childbirth Connection

NOTE: For guiding care, Childbirth Connection gives priority to systematic reviews. These rigorous summaries of best available evidence are the most trustworthy way to know the benefits and harms of specific practices.

When a cesarean is truly needed, its benefits likely outweigh possible downsides. However, without a clear medical reason for cesarean birth, vaginal birth is likely to be the far safer path for both you and your baby. This page summarizes results of systematic reviews comparing outcomes of cesarean and vaginal birth. We look at shorter- and longer-term outcomes in women, cesarean-born babies and babies in future pregnancies that develop in a scarred uterus. This page also reports on studies that point to problems that only occur with one or the other type of birth. (Problems that have been reported in individual studies but not summarized in systematic reviews are not described below.)

Is vaginal birth or C-section safer?

Vaginal birth is much safer than a C-section for most women and babies. But sometimes a C-section is the only safe option, like when the baby is positioned side-to-side in the belly (transverse lie) or the placenta is covering the cervix (placenta previa). In other situations, having a C-section might possibly have benefits, which need to be weighed against possible harms. You have the right to know these possible harms and benefits, and only you can decide how important they are to you.

What are the possible outcomes of C-section for women?

Systematic reviews have found that women with cesareans are more likely than women with vaginal birth to experience:

  • Impaired physical health for at least the first two months after birthVan der Woude, D.A., Pijnenborg, J.M., & de Vries, J. (2015). Health status and quality of life in postpartum women: A systematic review of associated factors. European Journal of Obstetrics & Gynecology and Reproductive Biology, 185, 45-52.
  • Emergency surgery to remove their uterus (hysterectomy)de la Cruz, C., Thompson, E., O’Rourke, K., & Nembhard, W. (2015). Cesarean section and the risk of emergency peripartum hysterectomy in high-income countries: A systematic review. Archives of Gynecology and Obstetrics, 292(6), 1201-15; Rossi, A., Lee, R., & Chmait, R. (2010). Emergency Postpartum Hysterectomy for Uncontrolled Postpartum Bleeding: A Systematic Review. Obstetrics & Gynecology, 115(3), 1453-1454.
  • Not establishing breastfeeding, which benefits both women and babies; this especially occurs when cesareans are scheduled before laborPrior, E., Santhakumaran, S., Gale, C., Philipps, L.H., Modi, N., & Hyde, M.J. (2012). Breastfeeding after cesarean delivery: a systematic review and meta-analysis of world literature. American Journal of Clinical Nutrition, 95, 1113-35.

In the long term, systematic reviews have found that women who have given birth by cesarean are more likely than those with vaginal births to experience:

  • Difficulty becoming pregnant, leading to a lower pregnancy rateGurol-Urganci, I., Bou-Antoun, S., Lim, C., Cromwell, D., Mahmood, T., Templeton, A., & Meulen, J. (2013). Impact of Caesarean section on subsequent fertility: A systematic review and meta-analysis. Human Reproduction, 28(7), 1943-1952.
  • Difficulty remaining pregnant, leading to a lower birth rateGurol-Urganci, I., Bou-Antoun, S., Lim, C., Cromwell, D., Mahmood, T., Templeton, A., & Meulen, J. (2013). Impact of Caesarean section on subsequent fertility: A systematic review and meta-analysis. Human Reproduction, 28(7), 1943-1952.
  • A desire to wait longer before becoming pregnant againO’Neill, S., Kearney, P., Kenny, L., Henriksen, T., Lutomski, J., Greene, R., & Khashan, A. (2013). Caesarean delivery and subsequent pregnancy interval: A systematic review and meta-analysis. BMC Pregnancy and Childbirth, 13, 165-165.
  • Ongoing pain in the pelvis areaLatthe, P., Mignini, L., Gray, R., Hills, R., & Khan, K. (2006). Factors predisposing women to chronic pelvic pain: a systematic review. BMJ, 332, 749-55.

What are the possible benefits and harms of having a vaginal birth?

Even though labor and vaginal birth can be hard work, they are generally easier on a woman’s body than a C-section. Recovery after vaginal birth is usually shorter and less painful than after a C-section, and allows the woman to spend more time with her baby.

New research is discovering ways that labor and vaginal birth are good for babies, too. The hormones that cause labor to start and progress actually help the baby get ready to be born and reduce the chance of breathing difficulties and other problems. These hormones help prepare mother and baby for a safe transition at the time of birth, and help them feel close and connected and get breastfeeding off to a good start.

Babies born vaginally also have lower rates of some serious childhood diseases like asthma, Type 1 diabetes and allergies, and are less likely to become obese. Researchers think these benefits have to do with healthy bacteria babies are exposed to during vaginal birth.

Other benefits include avoiding complications that can occur with major surgery like a C-section.

The following complications can happen with vaginal birth, but do not happen with cesarean birth:

  • Injury to the vulva or vagina, with possible pain and infection (genital trauma)
  • A tear or intentional cut (episiotomy) from the opening of the vagina toward the anus, with possible pain and infection (perineal trauma)

What problems can only happen if a woman has a c-section?

The following complications can happen with cesarean birth, but do not happen with vaginal birth:

  • Mistaken surgical cut to the mother
  • Mistaken surgical cut to the baby
  • Opening the closed wound to take care of a problem
  • Severe and/or long-term pain at the site of the cesarean cut
  • Infection introduced through the surgical cuts
  • A pregnancy that grows in a previous scar (cesarean ectopic pregnancy)
  • A placenta that implants in a previous scar (placenta accreta)
  • Internal scar tissue (dense adhesions) that make future surgeries more difficult and can cause more complicationsLyell, D.J., Caughey, A.B., Hu, E., & Daniels, K. (2005). Peritoneal closure at primary cesarean delivery and adhesions. Obstetrics & Gynecology, 106(2), 275-280.

What are the possible risks to my baby associated with C-section?

Systematic reviews have found that cesarean-born babies are more likely than vaginally-born babies to experience:

  • Not establishing breastfeeding; this especially occurs when C-sections are scheduled before laborPrior, E., Santhakumaran, S., Gale, C., Philipps, L.H., Modi, N., & Hyde, M.J. (2012). Breastfeeding after cesarean delivery: a systematic review and meta-analysis of world literature. American Journal of Clinical Nutrition, 95, 1113-35.
  • Increased risk of breathing problemsHansen, A.K., Wisborg, K., Uldjerg, N., & Henriksen, T.B. (2007). Elective caesarean section and respiratory morbidity in the term and near-term neonate. Acta Obstetrica et Gynecologica Scandanavia, 86, 389-94.
  • Less blood flowing from the placenta to the baby at birth and less ironZhou, Y., Li, H., Zhu, L., & Liu, J. (2014). Impact of cesarean section on placental transfusion and iron-related hematological indices in term neonates: A systematic review and meta-analysis. Placenta, 35, 1-8.

Systematic reviews have found that being born by cesarean rather than vaginally is associated with greater likelihood of developing several chronic diseases, including:

  • Childhood-onset (Type 1) diabetesCardwell, C., Stene, L., G, J., Cinek, O., Svensson, J., Goldacre, M., . . . Patterson, C. (2008). Caesarean section is associated with an increased risk of childhood-onset type 1 diabetes mellitus: A meta-analysis of observational studies. Diabetologia, 51(5), 726-35.
  • Childhood obesity, Kuhle, S., Tong, O., & Woolcott, C. (2015). Association between caesarean section and childhood obesity: A systematic review and meta-analysis. Obesity Reviews, 16, 295-303. obesity in adulthoodDarmasseelane, K., Hyde, M., Santhakumaran, S., Gale, C., & Modi, N. (2014). Mode of Delivery and Offspring Body Mass Index, Overweight and Obesity in Adult Life: A Systematic Review and Meta-Analysis. PLoS One, 9, e97827.or bothLi, H., Zhou, Y., & Liu, J. (2013). The Impact of Cesarean Section on Offspring Overweight and Obesity. Obstetrical & Gynecological Survey, 37, 9-11.
  • Autism spectrum disorderCurran, E., O’Neill, S., Cryan, J., Kenny, L., Dinan, T., Khashan, A., & Kearney, P. (2014). Research Review: Birth by caesarean section and development of autism spectrum disorder and attention-deficit/hyperactivity disorder: A systematic review and meta-analysis. Journal of Child Psychology and Psychiatry, 56, 500-508.
  • Chronic inflammatory bowel disease with abdominal pain, diarrhea, weight loss, anemia and fatigue (Crohn’s disease)Li, Y., Tian, Y., Zhu, W., Gong, J., Gu, L., Zhang, & W, Li, J. (2014). Cesarean delivery and risk of inflammatory bowel disease: A systematic review and meta-analysis. Scandinavian Journal of Gastroenterology, 49(7), 834-844.
  • AsthmaBager, P., Wohlfahrt, J., & Westergaard, T. (2008). Caesarean delivery and risk of atopy and allergic disease: Meta-analyses. Clinical & Experimental Allergy, 38(4), 634-642; Thavagnanam, S., Fleming, J., Bromley, A., Shields, M., & Cardwell, C. (2008). A meta-analysis of the association between Caesarean section and childhood asthma. Clinical & Experimental Allergy, 38, 629-633.
  • Food sensitivities and allergiesKoplin, J., Allen, K., Gurrin, L., Osborne, N., Tang, M., & Dharmage, S. (2008). Is caesarean delivery associated with sensitization to food allergens and IgE-mediated food allergy: A systematic review. Pediatric Allergy and Immunology, 19, 682-687.
  • Hay feverBager, P., Wohlfahrt, J., & Westergaard, T. (2008). Caesarean delivery and risk of atopy and allergic disease: Meta-analyses. Clinical & Experimental Allergy, 38(4), 634-642.

What are possible effects of a C-section on my future pregnancies and births?

Women with pregnancies after previous C-section are more likely than those without previous C-section to experience:

  • Splitting open of the scar in the uterus (uterine rupture)Hofmeyr, G.J., Say, L., & Gülmezoglu, A.M. (2005). WHO systematic Review of maternal mortality and morbidity: The prevalence of uterine rupture. BJOG: An International Journal of Obstetrics & Gynaecology, 112(9), 1221-1228.
  • Emergency surgery to remove the uterus (hysterectomy)de la Cruz, C., Thompson, E., O’Rourke, K., & Nembhard, W. (2015). Cesarean section and the risk of emergency peripartum hysterectomy in high-income countries: A systematic review. Archives of Gynecology and Obstetrics, 292(6), 1201-15; Rossi, A., Lee, R., & Chmait, R. (2010). Emergency Postpartum Hysterectomy for Uncontrolled Postpartum Bleeding: A Systematic Review. Obstetrics & Gynecology, 115(3), 1453-1454.
  • Serious condition of the placenta covering the opening of the cervix (placenta previa)Gurol-Urganci, I., Cromwell, D., Edozien, L., Smith, G., Onwere, C., Mahmood, T., & Meulen, J. (2011). Risk of placenta previa in second birth after first birth cesarean section: A population-based study and meta-analysis. BMC Pregnancy and Childbirth, 11, 95; Klar, M., Michels, K.B. (2014). Cesarean section and placental disorders in subsequent pregnancies: A meta-analysis. Journal of Perinatal Medicine, 42(5), 871-883.
  • Serious condition of the placenta growing into the wall of the uterus (placenta accreta)Klar, M., Michels, K.B. (2014). Cesarean section and placental disorders in subsequent pregnancies: A meta-analysis. Journal of Perinatal Medicine, 42(5), 871-883.
  • Serious condition of the placenta separating from the wall of the uterus before the birth (placental abruption)Klar, M., Michels, K.B. (2014). Cesarean section and placental disorders in subsequent pregnancies: A meta-analysis. Journal of Perinatal Medicine, 42(5), 871-883.
  • A stillborn babyMoraitis, A.A., Oliver-Williams, C., Wood, A.M., Fleming, M., Pell, J.P., & Smith, G.C.S. (2015). Previous caesarean delivery and the risk of unexplained stillbirth: retrospective cohort study and meta-analysis. BJOG: An International Journal of Obstetrics & Gynaecology, 122(11), 1467-1474; O’Neill, S., Kearney, P., Kenny, L., Khashan, A., Henriksen, T., Lutomski, J., & Greene, R. (2013). Caesarean Delivery and Subsequent Stillbirth or Miscarriage: Systematic Review and Meta-Analysis. PLoS One, 8(1), e54588..

A systematic review found that risk of the following complications associated with C-section increases with each additional C-section: Marshall, N., Fu, R., & Guise, J. (2011). Impact of multiple cesarean deliveries on maternal morbidity: A systematic review. American Journal of Obstetrics and Gynecology, 205(3), e1-8.

  • Measures of serious maternal health problems (severe morbidity)
  • Emergency surgery to remove the uterus (hysterectomy)
  • Serious condition of the placenta covering the opening of the cervix (placenta previa)
  • Serious condition of the placenta growing into the wall of the uterus (placenta accreta)
  • Excessive blood loss (hemorrhage)
  • Blood given through IV line (blood transfusion)
  • Scars that cause organs to bind together and may lead to pain and other problems (adhesions)
  • Surgical injury

A systematic review suggests why these conditions are “serious.”Vahanian, S.A., Lavery, J.A., Ananth, C.V., & Vintzileos, A. (2015). Placetal implantation abnormalities and risk of preterm delivery. A systematic review and metaanalysis. American Journal of Obstetrics & Gynecology, 213(4 Suppl), S78-90. The review found that placenta previa, when the placenta covers the opening of the uterus, is associated with increased risk of:

  • Preterm birth
  • Admission to neonatal intensive care unit (NICU)
  • Newborn death (in the 28 days after birth)
  • Perinatal death (combined late pregnancy and early postpartum death)

Even if you do not plan to have more babies, it is important to know about these risks because many women change their minds or have unplanned pregnancies.

Does C-section protect against sexual, bowel and urinary problems?

The best available research has found no difference between women with vaginal and cesarean birth for:

  • Anal incontinence (leakage of stool or gas)
  • Urge urinary incontinence (leakage of urine with a sense of “got to go”)
  • Any severe urine leakage

However, in the short and long term, best research finds that women with vaginal birth are more likely to experience stress urinary incontinence (leakage with exertion). Current studies cannot clarify whether this is due to vaginal birth itself or to practices that are common with vaginal birth. Concerning practices include:

  • Lying on your back or with legs in stirrups when pushing and giving birth (women with epidurals)
  • Assisted vaginal birth (with vacuum or forceps)
  • Common interventions that increase the likelihood of assisted vaginal birth (epidural analgesia, continuous electronic fetal monitoring)
  • Staff pushing on your upper belly to move the baby out (fundal pressure)
  • Episiotomy (a cut just before birth to enlarge the opening of the vagina)

It would be wise to avoid these practices when possible and to follow other practices (such as having a healthy weight and not smoking) that help avoid problems in your pelvic floor.

You can learn much more about these topics in the Pelvic Floor: Preventing Problems section.

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