Pregnancy Conditions Associated with Delayed Villous Maturation in
Placenta: A Systematic Review and Meta-Analysis
Abstract
Background Delayed villous maturation (DVM) also called DVI
(distal villous immaturity) is a placental maturation disorder that
mainly affects maternal-to-fetal oxygen transfer. Objective We
conducted a systematic review and meta-analysis of conditions associated
with histopathological findings of DVM based on pathologist assessment
after delivery. Search strategy Medline, EMBASE, Web of
Science, and MIDIRS databases were searched from inception to December
2023. Selection criteria Peer-reviewed, observational studies
including cohort, case-control, and cross-sectional studies reported the
histopathological findings of DVM after placenta delivery. Data
collection and analysis Two reviewers performed the systematic article
screening, bias assessment, and data extraction. Senior authors resolved
disagreement between reviewers. The risk of bias scoring was assessed
using the Newcastle-Ottawa scale for cohort and case-control studies.
The random-effect model was used for meta-analysis since there was
clinical and statistical heterogeneity ( I2)
across studies. For comparisons with an I2
value < 50% (low heterogeneity), the fixed-effect model was
used. Main result There were 52 included studies considered
eligible that reported DVM and linked pregnancy conditions. The
conditions associated with DVM in term placentas were gestational
diabetes (GDM) [OR(95%CI)=3.75(1.93, 7.29)], pregestational
diabetes (PGDM) [OR(95%CI)=2.64(1.65, 4.22)], obesity
[OR(95%CI)=1.91 (1.23, 2.98)], stillbirth [OR(95%CI)=5.46 (2.26,
13.20)], preterm birth [OR(95%CI)= 3.48 (1.11, 10.97)], and
congenital anomalies [OR(95%CI)= 7.57 (3.91, 14.65)].
Conclusion DVM is a placental abnormality associated with
dysmetabolism, particularly pregnancy diabetes, and obesity; and with
adverse outcomes including stillbirth and congenital anomalies. In
studies with variable DVM definition, it was also associated with
preterm birth. Optimising metabolism could avoid preventable harm to the
baby.