Placental weight and efficiency in relation to maternal body mass index and the risk of pregnancy complications in women delivering singleton babies

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Abstract

Herein we report placental weight and efficiency in relation to maternal BMI and the risk of pregnancy complications in 55,105 pregnancies. Adjusted placental weight increased with increasing BMI through underweight, normal, overweight, obese and morbidly obese categories and accordingly underweight women were more likely to experience placental growth restriction [OR 1.69 (95% CI 1.46-1.95)], while placental hypertrophy was more common in overweight, obese and morbidly obese groups [OR 1.59 (95% CI 1.50-1.69), OR 1.97 (95% CI 1.81-2.15) and OR 2.34 (95% CI 2.08-2.63), respectively]. In contrast the ratio of fetal to placental weight (a proxy for placental efficiency) was lower (P < 0.001) in overweight, obese and morbidly obese than in both normal and underweight women which were equivalent. Relative to the middle tertile reference group (mean 622 g), placental weight in the lower tertile (mean 484 g) was associated with a higher risk of pre-eclampsia, induced labour, spontaneous preterm delivery, stillbirth and low birth weight (P < 0.001). Conversely placental weight in the upper tertile (mean 788 g) was associated with a higher risk of caesarean section, post-term delivery and high birth weight (P < 0.001). With respect to assumed placental efficiency a ratio in the lower tertile was associated with an increased risk of pre-eclampsia, induced labour, caesarean section and spontaneous preterm delivery (P < 0.001) and a ratio in both the lower and higher tertiles was associated with an increased risk of low birth weight (P < 0.001). Placental efficiency was not related to the risk of stillbirth or high birth weight. No interactions between maternal BMI and placental weight tertile were detected suggesting that both abnormal BMI and placental growth are independent risk factors for a range of pregnancy complications.

Original languageEnglish
Pages (from-to)611-618
Number of pages8
JournalPlacenta
Volume33
Issue number8
Early online date11 Jun 2012
DOIs
Publication statusPublished - Aug 2012

Fingerprint

Pregnancy Complications
Body Mass Index
Mothers
Weights and Measures
Thinness
Induced Labor
Stillbirth
Low Birth Weight Infant
Pre-Eclampsia
Birth Weight
Cesarean Section
Proxy
Growth
Hypertrophy
Pregnancy

Keywords

  • Adult
  • Cohort Studies
  • Databases, Factual
  • Female
  • Great Britain
  • Humans
  • Hypertrophy
  • Obesity
  • Obesity, Morbid
  • Organ Size
  • Overweight
  • Placenta
  • Placental Insufficiency
  • Placentation
  • Pregnancy
  • Pregnancy Complications
  • Retrospective Studies
  • Risk Factors
  • Thinness
  • Young Adult

Cite this

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title = "Placental weight and efficiency in relation to maternal body mass index and the risk of pregnancy complications in women delivering singleton babies",
abstract = "Herein we report placental weight and efficiency in relation to maternal BMI and the risk of pregnancy complications in 55,105 pregnancies. Adjusted placental weight increased with increasing BMI through underweight, normal, overweight, obese and morbidly obese categories and accordingly underweight women were more likely to experience placental growth restriction [OR 1.69 (95{\%} CI 1.46-1.95)], while placental hypertrophy was more common in overweight, obese and morbidly obese groups [OR 1.59 (95{\%} CI 1.50-1.69), OR 1.97 (95{\%} CI 1.81-2.15) and OR 2.34 (95{\%} CI 2.08-2.63), respectively]. In contrast the ratio of fetal to placental weight (a proxy for placental efficiency) was lower (P < 0.001) in overweight, obese and morbidly obese than in both normal and underweight women which were equivalent. Relative to the middle tertile reference group (mean 622 g), placental weight in the lower tertile (mean 484 g) was associated with a higher risk of pre-eclampsia, induced labour, spontaneous preterm delivery, stillbirth and low birth weight (P < 0.001). Conversely placental weight in the upper tertile (mean 788 g) was associated with a higher risk of caesarean section, post-term delivery and high birth weight (P < 0.001). With respect to assumed placental efficiency a ratio in the lower tertile was associated with an increased risk of pre-eclampsia, induced labour, caesarean section and spontaneous preterm delivery (P < 0.001) and a ratio in both the lower and higher tertiles was associated with an increased risk of low birth weight (P < 0.001). Placental efficiency was not related to the risk of stillbirth or high birth weight. No interactions between maternal BMI and placental weight tertile were detected suggesting that both abnormal BMI and placental growth are independent risk factors for a range of pregnancy complications.",
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author = "Wallace, {J M} and Horgan, {G W} and S Bhattacharya",
note = "Copyright {\circledC} 2012 Elsevier Ltd. All rights reserved.",
year = "2012",
month = "8",
doi = "10.1016/j.placenta.2012.05.006",
language = "English",
volume = "33",
pages = "611--618",
journal = "Placenta",
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T1 - Placental weight and efficiency in relation to maternal body mass index and the risk of pregnancy complications in women delivering singleton babies

AU - Wallace, J M

AU - Horgan, G W

AU - Bhattacharya, S

N1 - Copyright © 2012 Elsevier Ltd. All rights reserved.

PY - 2012/8

Y1 - 2012/8

N2 - Herein we report placental weight and efficiency in relation to maternal BMI and the risk of pregnancy complications in 55,105 pregnancies. Adjusted placental weight increased with increasing BMI through underweight, normal, overweight, obese and morbidly obese categories and accordingly underweight women were more likely to experience placental growth restriction [OR 1.69 (95% CI 1.46-1.95)], while placental hypertrophy was more common in overweight, obese and morbidly obese groups [OR 1.59 (95% CI 1.50-1.69), OR 1.97 (95% CI 1.81-2.15) and OR 2.34 (95% CI 2.08-2.63), respectively]. In contrast the ratio of fetal to placental weight (a proxy for placental efficiency) was lower (P < 0.001) in overweight, obese and morbidly obese than in both normal and underweight women which were equivalent. Relative to the middle tertile reference group (mean 622 g), placental weight in the lower tertile (mean 484 g) was associated with a higher risk of pre-eclampsia, induced labour, spontaneous preterm delivery, stillbirth and low birth weight (P < 0.001). Conversely placental weight in the upper tertile (mean 788 g) was associated with a higher risk of caesarean section, post-term delivery and high birth weight (P < 0.001). With respect to assumed placental efficiency a ratio in the lower tertile was associated with an increased risk of pre-eclampsia, induced labour, caesarean section and spontaneous preterm delivery (P < 0.001) and a ratio in both the lower and higher tertiles was associated with an increased risk of low birth weight (P < 0.001). Placental efficiency was not related to the risk of stillbirth or high birth weight. No interactions between maternal BMI and placental weight tertile were detected suggesting that both abnormal BMI and placental growth are independent risk factors for a range of pregnancy complications.

AB - Herein we report placental weight and efficiency in relation to maternal BMI and the risk of pregnancy complications in 55,105 pregnancies. Adjusted placental weight increased with increasing BMI through underweight, normal, overweight, obese and morbidly obese categories and accordingly underweight women were more likely to experience placental growth restriction [OR 1.69 (95% CI 1.46-1.95)], while placental hypertrophy was more common in overweight, obese and morbidly obese groups [OR 1.59 (95% CI 1.50-1.69), OR 1.97 (95% CI 1.81-2.15) and OR 2.34 (95% CI 2.08-2.63), respectively]. In contrast the ratio of fetal to placental weight (a proxy for placental efficiency) was lower (P < 0.001) in overweight, obese and morbidly obese than in both normal and underweight women which were equivalent. Relative to the middle tertile reference group (mean 622 g), placental weight in the lower tertile (mean 484 g) was associated with a higher risk of pre-eclampsia, induced labour, spontaneous preterm delivery, stillbirth and low birth weight (P < 0.001). Conversely placental weight in the upper tertile (mean 788 g) was associated with a higher risk of caesarean section, post-term delivery and high birth weight (P < 0.001). With respect to assumed placental efficiency a ratio in the lower tertile was associated with an increased risk of pre-eclampsia, induced labour, caesarean section and spontaneous preterm delivery (P < 0.001) and a ratio in both the lower and higher tertiles was associated with an increased risk of low birth weight (P < 0.001). Placental efficiency was not related to the risk of stillbirth or high birth weight. No interactions between maternal BMI and placental weight tertile were detected suggesting that both abnormal BMI and placental growth are independent risk factors for a range of pregnancy complications.

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KW - Cohort Studies

KW - Databases, Factual

KW - Female

KW - Great Britain

KW - Humans

KW - Hypertrophy

KW - Obesity

KW - Obesity, Morbid

KW - Organ Size

KW - Overweight

KW - Placenta

KW - Placental Insufficiency

KW - Placentation

KW - Pregnancy

KW - Pregnancy Complications

KW - Retrospective Studies

KW - Risk Factors

KW - Thinness

KW - Young Adult

U2 - 10.1016/j.placenta.2012.05.006

DO - 10.1016/j.placenta.2012.05.006

M3 - Article

VL - 33

SP - 611

EP - 618

JO - Placenta

JF - Placenta

SN - 0143-4004

IS - 8

ER -