Comparison of morphometric and histological features of placenta of in vitro fertilization and naturally conceived pregnancies

Abstract

Aims: In vitro fertilization (IVF) is associated with an increased risk of placental abnormalities and placental-related complications. This study aimed to compare the morphological and histological features of placentae of IVF pregnancy with those of natural pregnancies. Methods: This cross-sectional study included placentae from both IVF and natural conception pregnant mothers aged between 20-45 years who delivered at Milan Fertility Center and Birthing Hospital, JP Nagar Bangalore. Pregnant women with hypertension, diabetes mellitus, anemia, multiple pregnancies, or preterm pregnancies were excluded from the study. Morphometric parameters of the placenta like weight, thickness, diameter, attachment of cord, and number of cotyledons were recorded, and histological examinations of placentae were performed. Results: The study included a total of 100 placentae, 50 from IVF pregnancy and 50 from natural pregnancy (age, mean±standard deviation: 31.5±3.0 years, IVF pregnant mothers; 30.9±4.0 years, natural pregnant mothers; p=0.254). The IVF group had a lower gestational ages at delivery (37.0±1.3 weeks vs. 38.1±0.9 weeks; p=0.001), low birth weight (BW) (2.7±0.5 kg vs. 3.0±0.5 kg; p=0.001), and increased placental thickness (2.43±0.36 cm vs. 2.17±0.39 cm; p=0.043). There was no significant difference in placental weight, placental diameter, and the mean number. of cotyledons between the two groups (p>0.05). The IVF group had an increased rate of velamentous cord insertion (20% vs. 2%; p=0.001) and marginal cord insertion (38% vs. 8%; p=0.001), calcification (74% vs. 54%, p=0.004), syncytial knot (44% vs. 38%; p=0.014), and fibrinoid necrosis (30% vs. 12%, p=0.027). Infarction and stromal fibrosis were also increased in IVF, but the difference was statistically in significant (p=0.052, 0.542 respectively). Conclusions: The IVF group had a higher incidence of marginal and velamentous insertion of the umbilical cord, increased placental thickness, low BW, and a higher tendency toward early calcification, infarction, and fibrosis.

Keywords

• in vitro fertilization (ivf)
• placenta
• histological
• morphological
• velamentous insertion