The survey was developed through a collaboration of investigators from the National Partnership for Women & Families, Boston University School of Public Health and University of California, San Francisco (UCSF) Center on Social Disparities in Health, who worked with Quantum Market Research to plan and carry out the survey. The sampling frame for the Listening to Mothers in California study was drawn from California birth certificate data for births between September 1 and December 15, 2016. Women less than 18, women with out-of-hospital births, women with multiple births, non-residents of California, women who could not respond in either English or Spanish and women who were not currently living with their baby were excluded from the sample. Of the final sample, 81% participated in English and 19% in Spanish. We oversampled Black women, women with midwifery-attended births and those with vaginal births after cesarean to have sample sizes to better understand the experiences, outcomes and views of women within these smaller groups. The survey was conducted from February 22 through August 15, 2017. Participants were recruited using up to four invitation and reminder mailings and inserts incorporating elements of informed consent and cards providing information about how to participate in the survey. Those who did not respond to mailings were contacted via emails, text messages and telephone calls. Sampled women were invited to participate on their own online using any device or with an interviewer via telephone. Respondents participated from 2 to 11 months after giving birth. Of those who completed the survey, 34% did so online, 28% did so by phone with an interviewer and 39% used both methods (typically starting on their own and finishing with an interviewer). 24
The survey questionnaire was pretested and refined in English and Spanish. On average, the survey took slightly more than 30 minutes to complete. The complete Listening to Mothers in California survey questionnaire and related materials are available at both nationalpartnership.org/LTMCA and chcf.org/listening-to-mothers-CA and the specific questions reported on here are attached as an Appendix. The dataset itself will be publically available at the University of North Carolina Dataverse (https://dataverse.unc.edu/ ).
To better reflect a statewide profile of childbearing women aged 18 and older and giving birth to single babies in California hospitals, the final sample was weighted using demographic and other relevant variables from the 2016 Birth Statistical Master File to be representative of the full year of 2016. Our final sample size of 2,539 women represented a response rate of 55%. A more detailed explanation of the methodology is presented in the Listening to Mothers in California full survey report appendices.24
The Committee for the Projection of Human Subjects of California’s Office of Statewide Health Planning and Development is the IRB of record and approved the study and subsequent protocol amendments. The UCSF IRB also approved the project. The California Department of Public Health Vital Statistics Advisory Committee approved access to birth certificate data. We also linked to the Management Information System/Decision Support System Warehouse of the Department of Health Care Services to definitively identify women with Medi-Cal coverage, defined as Warehouse evidence of a paid claim for a 2016 birth.
In these analyses, Latina indicates women who chose “Hispanic or Latina.” “White,” “Asian and Pacific Islander” and “Black” indicate women who did not choose “Hispanic or Latina” and self-identified, respectively, as white, Asian or Native Hawaiian or other Pacific Islander, or Black. We limited the sample for this specific analysis to the 2,119 women who indicated they had been planning to have a vaginal birth. We focused on attempted induction as the intervention that begins a potential series of other interventions rather than whether or not the induction actually began labor. We conducted bivariate analyses, examining associations between selected maternal socio-demographic characteristics, (including age, race/ethnicity, insurance, parity, body mass index (BMI), marital status, nativity, language used at home and education level), as well as maternal beliefs and preferences and attempted medical induction. We also examined the experience of women subsequent to receiving the attempted induction, their perception of whether they felt pressured to have an induction and the association of induction with other interventions during labor and delivery.
The determination of what was a medical induction was based on maternal responses to the question. “Why did your maternity care provider try to start your labor?” The response options were, “They were worried that I was “overdue,” “My water had broken and they worried about infection,” “The baby needed to be born soon due to a health problem (for one or both of us),” “My baby was getting too big,” “I wanted to control the timing for work or other nonmedical reasons,” “I wanted to give birth with a specific provider,” “Baby was full term: it was close to my due date,” or “Some other reason” and women could check all they felt applied. If a woman indicated one of the first three reasons it was classified as a medically indicated induction, even if she also checked one of the nonmedical indications. The open-ended responses to the “some other reason” option were also reviewed and classified as medically indicated or elective.
The first set of multivariable models examined the variables potentially related to attempted induction, elective induction and perceived pressure to have an induction. These included sociodemographic (race, age, education, parity and insurance), health (prepregnancy BMI, weeks of gestation), maternal attitude toward medical interference with labor, and a hospital-level measure of the cesarean birth rate among women with NTSV (nulliparous, term, singleton, vertex) births, divided into quartiles, as a proxy for the local maternity unit culture. A second set of models examined the relationship between medical induction, elective induction, successful and failed inductions and likelihood of cesarean section, controlling for many of the same variables.