American Journal of Obstetrics and Gynecology
ResearchObstetricsThe impact of postpartum contraception on reducing preterm birth: findings from California
Section snippets
Materials and Methods
The data analysis was approved by the University of California, San Francisco, Committee of Human Subjects Approval and the California State Committee of Human Subjects Protection. We built a cohort of women aged 12–44 years who received publicly funded contraceptive services in the 18 months after birth. We identified records for second or higher-order births among women from California’s 2011 Birth Statistical Master File and their prior births from earlier Birth Statistical Master Files.
Variables
This study explores whether contraceptive coverage and use within 18 months of the index birth were associated with decreased odds of a preterm birth. Contraceptive coverage estimates the amount of contraceptive supply that a woman received. The length of coverage is determined through applying an algorithm based on the specified method and the quantity dispensed (eg, the number of pill packs or condoms distributed) from pharmacy and on-site claims during the study period. For cases of method
Multivariable Model
We constructed a multivariate logistic model examining the relationship of contraceptive coverage with the outcome of preterm birth. Contraceptive coverage was defined as a continuous variable from 0–18 months. We controlled for demographic variables, including education level, race/ethnicity, nativity, age at index birth, and parity. We used software (SAS, version 9.2, PROC LOGISTIC; SAS Institute, Cary, NC) for all analyses.
Sample characteristics
The cohort consisted of 111,948 women who were seen at least once by a Medi-Cal or Family PACT provider within 18 months of delivery (Table 1). Of these women, 9.8% had a preterm birth. Among women with a preterm birth, 86.9% were moderate to late preterm, 8.6% very preterm, and 4.5% extremely preterm births. In the study cohort, nearly 95% of the births were normal-weight infants.
Most of the women received user-dependent hormonal contraceptives as their most effective method (Table 2) (54,845;
Comment
Our findings demonstrate a small, but significant reduction in preterm births attributable to provision of postpartum contraception in a diverse cohort of Medicaid patients. We found that for every month of contraceptive coverage, odds of a preterm birth decrease by 1.1%. This finding compares favorably with estimates of preterm birth reduction due to other interventions.11 For example, broadly implementing smoking cessation and progesterone supplementation interventions would have an estimated
References (43)
- et al.
Global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000
Lancet
(2012) - et al.
Lancet Neonatal Survival Steering Team. 4 Million neonatal deaths: When? Where? Why?
Lancet
(2005) - et al.
Long-term neurodevelopmental outcomes after intrauterine and neonatal insults: a systematic review
Lancet
(2012) - et al.
National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications
Lancet
(2012) - et al.
Preventing preterm births: analysis of trends and potential reductions with interventions in 39 countries with very high human development index
Lancet
(2013) American Gynecological and Obstetrical Society 2013: social determinants of reproductive health
Am J Obstet Gynecol
(2014)- et al.
Effects of birth spacing on maternal health: a systematic review
Am J Obstet Gynecol
(2007) - et al.
Effect of the interval between pregnancies on perinatal outcomes among white and black women
Am J Obstet Gynecol
(2001) - et al.
Interpregnancy intervals: impact of postpartum contraceptive effectiveness and coverage
Am J Obstet Gynecol
(2014) - et al.
The postpartum visit: it's time for a change in order to optimally initiate contraception
Contraception
(2008)
Sex during pregnancy and the first postnatal year
J Psychosom Res
Effect of interpregnancy interval on infant low birth weight: a retrospective cohort study using the Michigan maternally linked birth database
Matern Child Health J
Trends in preterm birth and perinatal mortality among singletons: United States, 1989 through 2000
Obstet Gynecol
Born too soon: the global action report on preterm birth
Births: final data for 2010
Natl Vital Stat Rep
Centers for Disease Control and Prevention. Preterm births–United States, 2006 and 2010
MMWR Surveill Summ
Births: final data for 2011
Natl Vital Stat Rep
The social determinants of infant mortality and birth outcomes in Western developed nations: a cross-country systematic review
Int J Environ Res Public Health
The impact of birth spacing on subsequent feto-infant outcomes among community enrollees of a federal healthy start project
J Community Health
Prenatal care and subsequent birth intervals
Perspect Sex Reprod Health
Cited by (31)
Short-interval pregnancy in the Illinois Medicaid population following delivery in Catholic vs non-Catholic hospitals
2022, ContraceptionCitation Excerpt :Women delivering at Catholic hospitals are left vulnerable as they are unaware of limitations to their care and are often unable to access postpartum contraceptive methods prior to hospital discharge. Barriers to postpartum contraception are particularly problematic given the well-supported benefits of access to such services including optimal birth spacing and decreased rates of preterm birth [7–9]. A significant strength of this study is the robustness of our findings, as demonstrated by stable estimates across multiple models.
Social disadvantage and its effect on maternal and newborn health
2021, Seminars in PerinatologyCitation Excerpt :A woman living within an environment of social disadvantage is at higher risk for pregnancy complications such as preterm delivery, congenital anomalies, and perinatal asphyxia, which can result in long term physical and developmental sequelae for the newborn that can further exacerbate social disadvantage.32 Impacts of adverse neonatal outcomes can persist into childhood and is associated with chronic disease in adulthood, perpetuating a cycle of of social disadvantage due to physical and intellectual disability for children, and financial and emotional stress to families.33-34 Poverty can independently contribute to adverse developmental outcomes.
Optimizing interconception care: Rationale for the IMPLICIT model
2020, Seminars in PerinatologyCitation Excerpt :Additionally, assuring an interpregnancy interval of at least 12 months may further reduce a woman's risk for spontaneous preterm birth as well as decrease infant mortality.12,22 Addressing family planning and contraceptive use with women helps assure healthy interpregnancy intervals.23,24 Preconception folic acid reduces neural tube defects by 50–80%; however, nationally, only 30% of non-pregnant women ages 18–45 years old take folic acid supplementation.17
Universal access to contraception: women, families, and communities benefit
2020, American Journal of Obstetrics and GynecologyCitation Excerpt :The risk of spontaneous preterm birth increases 4-fold among women whose interval between a prior delivery and the last menstrual period preceding their next pregnancy is ≤6 months.13 A cohort study of more than 112,000 women who were seen at least once by a provider within 18 months of delivery reported that for every month of contraceptive coverage, the risk of preterm birth decreased by 1.1%.14 Furthermore, women with a short interpregnancy interval (<18 months) have an increased risk of small-for-gestational-age infants and increased risk of fetal demise.10
Supported by the Office of Family Planning, Department of Health Care Services, State of California, contract number 12-89338 A2.
The authors report no conflict of interest.
All analyses, interpretations, and conclusions reached are those of the University of California, San Francisco, and not necessarily of the State of California.
Cite this article as: Rodriguez MI, Chang R, Thiel de Bocanegra H. The impact of postpartum contraception on reducing preterm birth: findings from California. Am J Obstet Gynecol 2015;213:703.e1-6.