Purpose of App Review

To explore the usability and reliability of the Pregnancy: Repeat C-section or VBAC? app as a guide for patients to decide between vaginal birth after cesarean-section (VBAC) or repeat cesarean-section delivery (repeat C/D).


Unfortunately, cesarean deliveries (C/D), which are a major abdominal surgery with attendant risks, are more common now than a few decades ago and repeat C/Ds even more so. To some obstetric care providers, there is nothing as fearful as the terms VBAC or trial of labor after cesarean section (TOLAC).

More recently, the obstetric community is pushing to find ways to prevent the first C/D (thereby decreasing subsequent), as well as offer more well-informed and safe opportunities for women to have the opportunity to try for a VBAC. Achieving this goal not only takes educating and training of providers, but of patients as well. The Pregnancy: Repeat C-section or VBAC? app aims to help patients decide between a RCD and VBAC using the patient’s characteristics  to provide individual recommendations regarding outcomes in written, numerical, and graphical formats.

User Interface

The home screen is inviting. You meet Dr. Albert’s assistant, Anna, who explains the purpose of the app: “estimating the chances for VBAC based on current scientific data.” A diagram shows the user what the two options for delivery (with the appropriate sub-options/outcomes).

Once the user is ready to provide information, the CONTINUE text takes the user to a series of 16 questions.  These range from patient age, to describing previous pregnancies, to the number of subsequent pregnancies desired.

The app’s assistant covers questions for known factors that increase and decrease the probability of a VBAC as listed in the American College of Obstetricians and Gynecologists (ACOG) Practice Bulletin on VBAC (#115, published 2010). Within the questions, you can navigate “back” and “next,” as well as to the home screen. If you have filled in all of the information, you can navigate to the results. You cannot navigate between non-sequential questions.

After taking in all of the patient’s information, three or four pages of results and recommendations are provided.

The content of the first results page provides individual-specific characteristics–such as time since last delivery. The chance of achieving a VBAC is listed as a percent and is compared to the “more” desirable percent chance of 80%. Factors making a successful VBAC more or less likely are listed, as is the chance of emergency C/D and several other important reminders.

The next section of results shows demonstrates graphically the chance for successful VBAC, the chance for adverse outcome in the current pregnancy, and the chance for adverse outcome including future pregnancies. The following section then looks at outcomes for the current pregnancy–baby death risk, baby injury risk, baby respiratory distress risk, mother death risk, uterine rupture risk, and hysterectomy risk.

The last results, other than the space for feedback, looks at outcomes for future pregnancies. This is done by displaying aggregated risks across additional pregnancies. The numbers change by how many future pregnancies are desired.

The last three sections allow you to learn additional information by flipping the graph–most of these link to an article in Wikipedia.

Evidence to support use

  • The app claims that it is based on good scientific data, but the scientific data and trials are not listed anywhere in the app. When the numbers can be so important, I would look to know what trials and references are being used before I could use the app in good faith.


  • $2.99


  • friendly and inviting user interface
  • Straightforward questions
  • Comprehensiveness of questions
  • Inclusion of important outcomes for delivery


  • References not provided
  • Percentages listed for success differ significantly from the one validated VBAC calculator
  • Extrapolation of data to multiple pregnancies without providing references on how these are calculated
  • Lack of navigation screens to move within questions
  • No referral to resources other than Wikipedia for more information
  • Does not explain that there is no universally accepted cut-off for chance of successful VBAC and when VBAC may or may not be indicated
  • Uses a high cutoff (80%) for recommendation for VBAC–the ACOG practice bulletin discusses a success cutoff  of 60-80%

Healthcare providers that could potentially benefit from the app

  • Any health care provider involved in providing care and counseling to pregnant women considering delivery options

Patients that may benefit from app

  • Those who want to learn about delivery options and what each means in terms of risk for particular outcomes


  • Pregnancy: Repeqat C-Section or VBAC? is an easy-to-use app that calculates the chance of VBAC success, relying on non-referenced current scientific data.
  • graphic presentation of undesirable outcomes compared between VBAC and C/D helpful for patient education

I love the idea of this app, but I am concerned about not being able to trust it to provide reliable guidance for my patients. When I compared the same patient characteristics between this app and the validated VBAC calculator, I got drastically different calculcations – 60% success for 80% success for the same age, race/ethnicity, BMI, indication for prior delivery, number of vaginal deliveries.

Instead of making patient education more straightforward, I feel that I would spend time explaining why I do not believe a particular statement applies to this patient. The section on risk of future pregnancies is a bit of a stretch for me as I do not think the data is robust enough to provide these projections reliably. Given these reservations, I cannot recommend this app for my patients at this time. The app is available for the iPad.  It is not available on Android or iPhone.

iPad iTunes Link

iMedicalApps recommended?

  • No

Rating: 2.9
1. User Interface – 3.5  Limited navigation within app
2. Multimedia usage – 3
3. Price – 4.5
4. Real world applicability – 1


  • GrobmanWA, LaiY, LandonMB, SpongCY, LevenoKJ, Rouse DJ, et al. Development of a nomogram for predic- tion of vaginal birth after cesarean delivery. National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU). Obstet Gynecol 2007;109:806–12. (Level III)
  • American College of Obstetricians and Gynecologists (ACOG). Vaginal birth after previous cesarean delivery. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2010 Aug. 14 p. (ACOG practice bulletin; no. 115)

This post does not establish, nor is it intended to establish, a patient physician relationship with anyone. It does not substitute for professional advice, and does not substitute for an in-person evaluation with your health care provider. It does not provide the definitive statement on the subject addressed. Before using these apps please consult with your own physician or health care provider as to the apps validity and accuracy as this post is not intended to affirm the validity or accuracy of the apps in question. The app(s) mentioned in this post should not be used without discussing the app first with your health care provider.