Effects of intra-abdominal hypertension on maternal-fetal outcomes in term pregnant women: A systematic review

OBJECTIVE: To carry out a systematic review to assess the effects of intra-abdominal hypertension on maternal-fetal outcomes. METHODS: The search was carried out between 28(th) June to 4(th) July 2022 on the Biblioteca Virtual em Saúde, Pubmed, Embase, Web of Science, and Cochrane databases. The study was registered in PROSPERO (CRD42020206526). The systematic review was performed according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. To assess the methodological quality and control the risk of bias, New Castle was used. RESULTS: A total of 6203 articles were found. Of these, 5 met the selection criteria for a full reading. The selected studies included a total of 271 pregnant women, of which 242 underwent elective cesarean section and measurement of intra-abdominal pressure via a bladder catheter. In both pregnant women groups, the lowest intra-abdominal pressure values were found in the supine position with left lateral tilt. Prepartum values in normotensive women with singleton pregnancy (7.3±1.3 to 14.1 ± 1 mmHg) were lower than in gestational hypertensive disorders (12.0±3.3 to 18.3±2.6 mmHg). In postpartum, the values decreased in both groups but were even lower in normotensive women (3.7±0.8 to 9.9 ± 2.6 mmHg vs 8.5 ± 3.6 to 13.6 ± 3.3 mmHg). The same was true for twin pregnancies. The Sequential Organ Failure Assessment index ranged from 0.6 (0.5) to 0.9 (0.7) in both groups of pregnant women. The placental malondialdehyde levels were statistically (p < 0.05) higher in pregnant women with pre-eclampsia (2.52±1.05) than normotensive (1.42±0.54). CONCLUSIONS: Prepartum intra-abdominal pressure values in normotensive women were close or equal to intra-abdominal hypertension and compatible with gestational hypertensive disorders even in the postpartum period. IAP values were consistently lower in supine position with lateral tilt in both groups. Significant correlations were found between prematurity, low birth weight, pregnant women with hypertensive disorders, and increased intra-abdominal pressure. However, there was no significant association of dysfunction in any system in the relationship between intra-abdominal pressure and Sequential Organ Failure Assessment. Despite the higher malondialdehyde values in pregnant women with pre-eclampsia, the findings were inconclusive. Given the observed data on maternal and fetal outcomes, it would be recommended that intra-abdominal pressure measurements be standardized and used as a diagnostic tool during pregnancy. TRIAL REGISTRATION: PROSPERO registration: October 9th, 2020, CRD42020206526.