Low placental weight and altered metabolic scaling after severe acute respiratory syndrome coronavirus type 2 infection during pregnancy: a prospective multicentric study.

OBJECTIVES: A higher risk of adverse pregnancy outcomes is associated with SARS-CoV-2 infection; this could be partially explained by an altered placental function. Because histopathology is often unspecific, we aimed to assess placental weight, birthweight/placental weight (b/p) ratio, and the metabolic scaling exponent ß, an indicator of normal fetal-placental growth, to analyze placental function. METHODS: We included 153 singleton pregnancies with SARS-CoV-2-positive PCR result who delivered at three referring hospitals in Switzerland. Placental weight and b/p ratio were compared to published reference charts. Logistic regression analysis investigated the role of time of infection and other confounding factors on placental weight. The scaling exponent ß was compared to the reference value of 0.75. RESULTS: Placental weight was inferior or equal to the tenth centile in 42.5% (65 of 153) and to the third centile in 19% (29 of 153) of the cases. The risk of low placental weight was not influenced by the trimester in which infection occurred. The b/p ratio was >50th centile in 80.4% (123 of 153) of the cases. The incidence of foetal growth restriction, preeclampsia, and gestational diabetes was 11.8% (18 of 153), 3.3% (5 of 153), and 19.6% (30 of 153). Linear regression modelling revealed a pathologic metabolic scaling exponent ß of 0.871 ± 0.064 (R2 = 0.56). DISCUSSION: SARS-CoV-2 infection during pregnancy was associated with a higher incidence of low placental weight, an increased b/p ratio, and an abnormal scaling exponent ß in our cohort. This could be particularly relevant for the still controversial issue of an increased stillbirth rate in SARS-CoV-2 infection during pregnancy. In this regard, intensified foetal surveillance should be mandatory in these pregnancies.

Factors contributing to late stillbirth among women with pregnancy hypertension in a developing country.

OBJECTIVE: To investigate the factors associated with late stillbirth among women with hypertensive disorders of pregnancy (HDP). MATERIAL AND METHODS: The clinical details of women with HDP having late stillbirth were compared with controls having livebirth. RESULTS: Total 208 cases and 288 controls were included in the study. Inadequate antenatal visits (p < 0.001, OR-5.92). birth weight < 2000 gms (p < 0.001, OR 10.3) and BW/PW ratio > 8 contributed significantly (p = 0.0001, OR-5.6) to stillbirth. CONCLUSION: Poor antenatal care, birth weight below 2000gms and high BW/PW ratio was associated with a higher risk of stillbirth.

Placental weight and birth weight to placental weight ratio in monochorionic and dichorionic growth-restricted and non-growth-restricted twins

OBJECTIVE: The aim of the present study was to compare the placental weight and birth weight/placental weight ratio for intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. METHODS: This was a retrospective analysis of placentas from twin pregnancies. Placental weight and the birth weight/placental weight ratio were compared in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. The association between cord insertion type and placental lesions in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins was also investigated. RESULTS: A total of 105 monochorionic (intrauterine growth restriction=40; non-intrauterine growth restriction=65) and 219 dichorionic (intrauterine growth restriction=57; non-intrauterine growth restriction=162) placentas were analyzed. A significantly lower placental weight was observed in intrauterine growth-restricted monochorionic (p=0.022) and dichorionic (p<0.001) twins compared to non-intrauterine growth-restricted twins. There was no difference in the birth weight/placental weight ratio between the intrauterine growth restriction and non-intrauterine growth restriction groups for either monochorionic (p=0.36) or dichorionic (p=0.68) twins. Placental weight and the birth weight/placental weight ratio were not associated with cord insertion type or with placental lesions. CONCLUSION: Low placental weight, and consequently reduced functional mass, appears to be involved in fetal growth restriction in monochorionic and dichorionic twins. The mechanism by which low placental weight influences the birth weight/placental weight ratio in intrauterine growth-restricted monochorionic and dichorionic twins needs to be determined in larger prospective studies.

The significance of placental ratios in pregnancies complicated by small for gestational age, preeclampsia, and gestational diabetes mellitus.

OBJECTIVE: This study aimed to evaluate the placental weight, volume, and density, and investigate the significance of placental ratios in pregnancies complicated by small for gestational age (SGA), preeclampsia (PE), and gestational diabetes mellitus (GDM). METHODS: Two hundred and fifty-four pregnant women were enrolled from August 2005 through July 2013. Participants were divided into four groups: control (n=82), SGA (n=37), PE (n=102), and GDM (n=33). The PE group was classified as PE without intrauterine growth restriction (n=65) and PE with intrauterine growth restriction (n=37). Birth weight, placental weight, placental volume, placental density, and placental ratios including birth weight/placental weight ratio (BPW) and birth weight/placental volume ratio (BPV) were compared between groups. RESULTS: Birth weight, placental weight, and placental volume were lower in the SGA group than in the control group. However, the BPW and BPV did not differ between the two groups. Birth weight, placental weight, placental volume, BPW, and BPV were all significantly lower in the PE group than in the control group. Compared with the control group, birth weight, BPW, and BPV were higher in the GDM group, whereas placental weight and volume did not differ in the two groups. Placental density was not significantly different among the four groups. CONCLUSION: Placental ratios based on placental weight, placental volume, placental density, and birth weight are helpful in understanding the pathophysiology of complicated pregnancies. Moreover, they can be used as predictors of pregnancy complications.

The significance of placental ratios in pregnancies complicated by small for gestational age, preeclampsia, and gestational diabetes mellitus

OBJECTIVE: This study aimed to evaluate the placental weight, volume, and density, and investigate the significance of placental ratios in pregnancies complicated by small for gestational age (SGA), preeclampsia (PE), and gestational diabetes mellitus (GDM). METHODS: Two hundred and fifty-four pregnant women were enrolled from August 2005 through July 2013. Participants were divided into four groups: control (n=82), SGA (n=37), PE (n=102), and GDM (n=33). The PE group was classified as PE without intrauterine growth restriction (n=65) and PE with intrauterine growth restriction (n=37). Birth weight, placental weight, placental volume, placental density, and placental ratios including birth weight/placental weight ratio (BPW) and birth weight/placental volume ratio (BPV) were compared between groups. RESULTS: Birth weight, placental weight, and placental volume were lower in the SGA group than in the control group. However, the BPW and BPV did not differ between the two groups. Birth weight, placental weight, placental volume, BPW, and BPV were all significantly lower in the PE group than in the control group. Compared with the control group, birth weight, BPW, and BPV were higher in the GDM group, whereas placental weight and volume did not differ in the two groups. Placental density was not significantly different among the four groups. CONCLUSION: Placental ratios based on placental weight, placental volume, placental density, and birth weight are helpful in understanding the pathophysiology of complicated pregnancies. Moreover, they can be used as predictors of pregnancy complications.