Abstract

BACKGROUND

Women seeking VBAC may find limited in-hospital options. Increasing numbers of US women are delivering by VBAC out-of-hospital. Little is known about neonatal outcomes among those delivering by VBAC in vs. out-of-hospital.

OBJECTIVE(S)

To compare neonatal outcomes between women delivering via VBAC in hospital vs. out-of-hospital (home and freestanding birth center).

STUDY DESIGN

Retrospective cohort study using 2007-2010 linked US birth and death records to compare singleton, term, vertex, non-anomalous, live born neonates who delivered by VBAC in or out-of-hospital. Descriptive statistics and multivariate regression analyses were conducted to estimate unadjusted, absolute, and relative birth setting risk differences. Stratification by parity and history of vaginal birth examined association between birth setting and each outcome. Sensitivity analyses involving three transfer status scenarios were conducted.

RESULTS

A small proportion of the total number of US women with a history of cesarean (n = 1,138,813) delivered by VBAC (n = 109,970, 9.65%) with a large majority of these delivering in-hospital (n = 106,823, 97.14%). The proportion of home VBAC births increased from 1.78% to 2.45%. A pattern of increased neonatal morbidity was noted in unadjusted analysis (neonatal seizures, Apgar score <7 or <4, neonatal seizures), with higher morbidity noted in the out-of-hospital setting (neonatal seizures: 23 (0.02%) vs. 6 (0.19%), p <0.001; Apgar score <7: 2859 (2.68%) vs. 139 (4.42%), p <0.001; Apgar score <4: 431 (0.4%) vs. 23 (0.73), p = 0.01). A similar, but non-significant, pattern of increased risk was observed for neonatal death and ventilator support among those born in the out-of-hospital setting. Multivariate regression estimated that neonates born out-of-hospital had higher odds of poor outcomes (neonatal seizures (adjusted odds ratio [aOR] 8.53, 95% confidence interval [CI] 2.87-25.4); Apgar <7 (aOR, 1.62; 95% CI, 1.35-1.96); Apgar <4 (aOR 1.77, CI 1.12-2.79)). While odds of neonatal death (aOR, 2.1; CI 0.73-6.05, p = 0.18) and ventilator support (aOR 1.36, CI 0.75-2.46) appeared to be increased in out-of-hospital settings, findings did not reach statistical significance. Women birthing their second child by VBAC in out-of-hospital settings had higher odds of neonatal morbidity and mortality compared to women of higher parity. Women without a history of vaginal birth prior to out-of-hospital VBAC delivery had higher odds of neonatal morbidity and mortality compared to those with a history of vaginal birth. Sensitivity analyses generated distributions of plausible alternative estimates by outcome

CONCLUSIONS

Fewer than 1 in 10 US women with a prior CD delivered by VBAC in any setting and increasing proportions of these women delivered out-of-hospital. Adverse outcomes were more frequent for neonates born out-of-hospital, with risk concentrated among women birthing their second child and women without a history of vaginal birth. This information urgently signals the need to increase availability of in-hospital VBAC as well as suggests there may be benefit associated with increasing options that support physiologic birth and safely prevent primary cesareans. Results may inform evidence-based recommendations for birthplace among women seeking VBAC.

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Citation

Tilden, E. L., Cheyney, M., Guise, J. M., Emeis, C., Lapidus, J., Biel, F. M., … & Snowden, J. M. (2017). Vaginal birth after cesarean: neonatal outcomes and United States birth setting. American journal of obstetrics and gynecology216(4), 403-e1.