Delivery indication matters for perinatal outcomes in late preterm newborns

Abstract

Background

The late preterm (LP) rate in Western countries is 3–6% of all births, accounting for about two-thirds of the entire preterm population. However, all LP babies are not the same.

Aims

To identify pregnancies at risk for adverse outcomes in the LP period, we investigated how gestational age (GA) at delivery, delivery indication and prenatal risk factors may affect neonatal outcomes.

Study design

Prospective cohort study among singleton infants born between 34 + 0 and 36 + 6 weeks, in Emilia Romagna, Italy, during 2013–2015.

Outcomes measures

The primary outcome was a composite of adverse perinatal outcomes. Multivariate logistic regression models were used to, respectively, investigate the effects of GA at delivery, circumstances at parturition and prenatal risk factors, on study outcomes after controlling for confounding variable.

Results

Among 1867 births, 302, 504, and 1061 infants were born at 34, 35, and 36 weeks, respectively. There were no neonatal deaths. An increased risk of composite neonatal outcome was observed among 34 and 35 weeks deliveries compared with 36 weeks, and among indicated deliveries compared with spontaneous. When studying prenatal risk factors, neonatal morbidity was associated with pre gestational diabetes, preterm premature rupture of membranes (pPROM), maternal obesity, bleeding and polyhydramnios; instead, preeclampsia had a protective effect.

Conclusion

LP with indicated deliveries at 34 or 35 weeks, or with specific prenatal risk factors have worse neonatal outcome when compared to 36. Such differences should be considered when counseling patients and planning interventions such as timing of delivery in LP period.

Keywords:

• Late preterm
• p PROM
• medical indication
• perinatal outcomes

Acknowledgments

The authors are indebted to all colleagues and research fellows for their contributions to data collection:

Bologna Research Team: Maria Bisulli (Obstetric Unit), Nicola Rizzo (Obstetric Unit), Elisa Moro (Obstetric Unit), Silvia Vandini (Neonatal Unit) from Ospedale S. Orsola- Malpighi di Bologna; Francesco Giura (Neonatal Unit), Fabrizio Sandri (Neonatal Unit), Paola Murano (Obstetric Unit), Barbara Di Marcobernardino (Obstetric Unit), Giorgio Scagliarini (Obstetric Unit) from Ospedale Maggiore of Bologna.

Romagna Research Team: Elena Baudassi (Neonatal Unit) from Ospedale Infermi of Rimini

Parma and Piacenza Research Team: Federica Tamarri (Neonatal Unit), Cinzia Magnani (Neonatal Unit), Alice Suprani (Obstetric Unit), from the Department of Medicine and Surgery, University of Parma; Bruno Mandelli (Obstetric Unit), Melissa Bellini (Pediatric Unit), Luca Le Pera (Pediatric Unit) from the Ospedale of Piacenza; Maria Luisa Bidetti (Pediatric Unit), Giuseppe Crovini (Obstetric Unit) from Ospedale of Fidenza; Salvatore Anfuso (Obstetric Unit), Antonio Albarelli (Obstetric Unit) from Ospedale of Borgotaro.

Modena Research Team: Petrella Elisabetta (Obstetric Unit), Isotta Guidotti (Neonatal Unit), Fabrizio Ferrari (Neonatal Unit), Mariamaddalena Carbone (Obstetric Unit), from Mother-Infant and Adult Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena.

Reggio Emilia Research Team: Marina Palmieri (neonatal Unit), Flavio Vanacore (Obstetric Unit) from Arcispedale Santa Maria Nuova, IRCCS, Reggio Emilia, Lisa Melandri (Pediatric Unit) from Ospedale of Montecchio and Ospedale of Scandiano, Marcella Palmisano (Obstetric Unit) from Ospedale of Guastalla.

Author contributions

F. M. was responsible for designing the review protocol, writing the protocol and report, conducting the search, extracting and analyzing data, interpreting results, updating reference lists and creating “Summary of findings” tables. G. C. was responsible for extracting and analyzing data, conducing the metaregression analyses, interpreting results, updating reference lists and creating “Summary of findings” tables. M. B. contributed to writing the report, extracting and analyzing data, interpreting results, G. G., D. B., and A. C. contributed to designing the review protocol, writing the protocol and interpreting results. F. F. was responsible for designing the review protocol and provided feedback on the report.

Disclosure statement

The authors declare that they have no competing financial interests in relation to the work described.

Additional information

Funding

The study was financed by the Emilia Romagna County Grant [no. 417149 _ 2014].