Interbirth Interval With Frequency of Cesarean Delivery

The effect of interpregnancy interval on the risk for cesarean delivery following prior vaginal delivery

Prior vaginal delivery remains preventative of cesarean delivery despite increasing interpregnancy interval; therefore, patients should be encouraged to attempt vaginal delivery regardless of interpregnancy interval.

Birth spacing and risk of adverse pregnancy and birth outcomes: A systematic review and dose-response meta-analysis

INTRODUCTION

The association between extreme birth spacing and adverse outcomes is controversial, and available evidence is fragmented into different classifications of birth spacing.

MATERIAL AND METHODS

We conducted a systematic review of observational studies to evaluate the association between birth spacing (i.e., interpregnancy interval and interoutcome interval) and adverse outcomes (i.e., pregnancy complications, adverse birth outcomes). Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated using a random-effects model, and the dose-response relationships were evaluated using generalized least squares trend estimation.

RESULTS

A total of 129 studies involving 46 874 843 pregnancies were included. In the general population, compared with an interpregnancy interval of 18-23 months, extreme intervals (<6 months and ≥ 60 months) were associated with an increased risk of adverse outcomes, including preterm birth, small for gestational age, low birthweight, fetal death, birth defects, early neonatal death, and premature rupture of fetal membranes (pooled OR range: 1.08-1.56; p < 0.05). The dose-response analyses further confirmed these J-shaped relationships (pnon-linear  < 0.001-0.009). Long interpregnancy interval was only associated with an increased risk of preeclampsia and gestational diabetes (pnon-linear  < 0.005 and pnon-linear  < 0.001, respectively). Similar associations were observed between interoutcome interval and risk of low birthweight and preterm birth (pnon-linear  < 0.001). Moreover, interoutcome interval of ≥60 months was associated with an increased risk of cesarean delivery (pooled OR 1.72, 95% CI 1.04-2.83). For pregnancies following preterm births, an interpregnancy interval of 9 months was not associated with an increased risk of preterm birth, according to dose-response analyses (pnon-linear  = 0.008). Based on limited evidence, we did not observe significant associations between interpregnancy interval or interoutcome interval after pregnancy losses and risk of small for gestational age, fetal death, miscarriage, or preeclampsia (pooled OR range: 0.76-1.21; p > 0.05).

CONCLUSIONS

Extreme birth spacing has extensive adverse effects on maternal and infant health. In the general population, interpregnancy interval of 18-23 months may be associated with potential benefits for both mothers and infants. For women with previous preterm birth, the optimal birth spacing may be 9 months.

Risk for Cesarean section in women of advanced maternal age under the changed reproductive policy in China: A cohort study in a tertiary hospital in southwestern China

AIM

To describe changed epidemiological features of advanced maternal age (AMA) and to examine the effect of AMA on the risk for Cesarean section (CS) in a Chinese pregnant population.

METHODS

This retrospective single-center cohort study investigated the changes of epidemiological features of AMA parturients with respect to the revised reproductive policy in China in 43 702 singleton deliveries with live birth at ≥28 weeks managed from January 2005 to December 2016. We also evaluated the pregnancy outcomes in different age groups and risk factors of CS with multivariate analysis.

RESULTS

In this 12-year study period, the average maternal age increased from 28.5 to 30.2 years, and the proportion of AMA raised from 6.5% to 17.2%. AMA was significantly associated with increased risk of adverse pregnancy outcomes, and after adjustment for confounding factors, AMA remained a significant independent risk factor for CS. Furthermore, the effect of AMA in nulliparous women on the risk of CS was more significant than in multiparous women, while the history of previous CS (adjusted odds ratio 39.85) and interdelivery interval ≥10 years (adjusted odds ratio 1.52) also increased the risk of CS in multiparous women.

CONCLUSION

AMA increased the risk of a number of adverse pregnancy outcomes, and was independently associated with increased risk for CS. The increasing number of AMA parturients with risk factors is likely to increase CS rate in China in the near future, thus it is imperative to reduce the rate of primary CS as a matter of policy.

Does the interval since vaginal delivery influence the chance of vaginal birth after cesarean?

OBJECTIVE

To examine the association between interval since vaginal delivery and vaginal birth after cesarean (VBAC).

METHODS

Women with one prior low transverse cesarean and a prior vaginal delivery undergoing a trial of labor after cesarean at term were included in this cohort study. Multivariable analyses were performed to determine whether length of time since prior vaginal delivery was independently associated with VBAC and, if so, whether its inclusion enhanced the predictive capacity of previously published models.

RESULTS

Of the 5628 women included, 4901 (87%) achieved a VBAC. Each additional year since vaginal delivery decreased the odds of VBAC by 11% (95% CI: 10-13%). When added to an existing predictive model that included only factors available at early prenatal care, interval since vaginal delivery marginally improved the model's predictive ability (area under the curve [AUC] 0.73 versus 0.71, p < 0.01). When added to a model that included factors available proximate to the time of delivery, the addition of interval since vaginal delivery did not change the AUC (0.76 versus 0.75, p = 0.08).

CONCLUSIONS

A longer interval since vaginal delivery is associated with a decreased odd of VBAC. However, the addition of this interval to VBAC prediction models does not substantively improve their predictive ability.

Effect of an educational script on postpartum contraceptive use: a randomized controlled trial

OBJECTIVES

Short interpregnancy intervals are associated with adverse perinatal outcomes. Increased postpartum use of long-acting reversible contraception (LARC) could reduce short interpregnancy intervals. Therefore, the primary objective of our study was to evaluate if a postpartum educational script about LARC (LARC script) could increase postpartum LARC utilization at the 6-week postpartum visit.

STUDY DESIGN

We completed a randomized controlled trial (1:1) of 800 postpartum women in Raleigh, North Carolina. Women were recruited from the postpartum unit and randomized to receive (intervention) or not receive (control) the LARC script prior to hospital discharge. We conducted follow-up phone interviews to assess LARC use after their 6-week postpartum visit. We used Pearson's chi-squared test to compare LARC use between arms.

RESULTS

Between May 2011 and January 2012, 400 women were randomized to each arm. Three hundred sixty-nine women (92.3%) in each arm were successfully contacted after their 6-week postpartum visit. LARC use was reported by 17.6% and 13.3% of women in the intervention and control arms, respectively (p=.103).

CONCLUSIONS

The LARC script did not increase LARC utilization at the 6-week postpartum visit. Future studies should evaluate interventions that address both educational and systematic barriers to postpartum LARC uptake.

IMPLICATIONS

Use of a postpartum educational script focused on the intrauterine device and contraceptive implant did not increase their utilization after the 6-week postpartum visit. Future studies should evaluate interventions that address both educational and systematic barriers to postpartum contraceptive uptake.