Preterm prelabor rupture of membranes: evaluating latency and neonatal morbidity for pregnancies with expectant management ≥34 weeks

Abstract

Objective

To evaluate the association between latency and neonatal morbidity for pregnancies with expectant management of PPROM ≥34 w.

Materials and Methods

A retrospective cohort of singletons with PPROM from 2011 to 2016. Exposure was defined as latency (period from diagnosis of PPROM to delivery) and was analyzed as a count variable (i.e. number of days) and binary variable (≥7 days and <7 days; ≥21 days and <21 days). Primary outcome was composite neonatal morbidity defined as need for respiratory support, culture positive neonatal sepsis, and/or neonatal antibiotics >72 h. Fisher’s exact test, chi-square test, Mann–Whitney U and binary logistic regression tests were performed with p<.05 considered significant.

Results

Of 813 pregnancies, 104 met inclusion criteria: 73 (70.2%) pregnancies with PPROM diagnosed at <34 weeks and 31 (29.8%) pregnancies with PPROM diagnosed ≥34 weeks. A total of 58 (55.8%) pregnancies had a latency of ≥7 days and 46 (44.2%) had a latency <7 days. There was no difference in composite neonatal morbidity for latency ≥7 d versus <7 d (aOR 0.92; 95% CI 0.30–2.82) or latency as a count variable (aOR 0.70; 95% CI 0.23–2.13). However, a latency ≥21 d was associated with increased composite neonatal morbidity (aOR 10.24, 95% CI 1.42–73.99).

Conclusion

In pregnancies with PPROM expectantly managed ≥34 w, a latency of ≥7 d is not associated with significant differences in neonatal morbidity. However, different latency thresholds may be more clinically relevant for late preterm pregnancies. The increase in composite neonatal morbidity associated with a latency >21 days should be an area of future investigation and may suggest there is a population of pregnancies with PPROM which may not benefit from expectant management past 34 weeks.

Keywords:

• Preterm prelabor rupture of membranes
• latency
• late preterm

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

TL, AM, AD, CS: Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; AND

TL, AM, AD, CS: Drafting the work or revising it critically for important intellectual content; AND

TL, AM, AD, CS: Final approval of the version to be published; AND

TL, AM, AD, CS: Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.