Aim: To assess bone mineral density (BMD) and bone mineral content (BMC) of offspring born from a preeclamptic pregnancy.

Hypothesis: We hypothesise, based on the limited available evidence on this topic, that offspring who were 'exposed' to preeclampsia will have a higher bone mineral density than those who were not exposed.

Exposure variables: Preeclampsia and gestational hypertension

Outcome variables: Bone mineral density and content (as measured by DXA and pQCT)

Confounding/mediator variables: SES, maternal smoking, maternal BMI, maternal ethnicity, maternal age, maternal alcohol consumption, maternal physical activity, maternal vitamin D & Calcium intake, offspring weight/height, offspring total body fat mass/lean mass, CTX, Insulin, parity, birthweight, gestational age.

Summary:

Preeclampsia is the leading cause of perinatal and maternal mortality and morbiditiy and effects around 3% of all pregnancies worldwide. The only current cure is the delivery of the placenta and thus often results in an iatrogenic preterm delivery. The fetus has the greatest demand for calcium during the third trimester, so consequently a preterm delivery can result in insufficient bone mineralization (Weiler et al. 2002). A recent study has suggested that in pregnancies compliated by preeclampsia additional mechanisms may exist which result in protective effects on long term bone health in the offspring, both in preterm and term births (Miettola et al. 2013). However, this study was limited by a small sample size and no maternal lifestyle information. This study warrants replicating with larger numbers and more comprehensive confounder adjustment.

We hope to use the ALSPAC data to explore the association between preeclampsia (and gestational hypertension) in term and preterm births with bone parameters from recently collected DXA and pQCT scan data.

References

Miettola S, Hovi P, Andersson S et al. Maternal preeclampsia and bone mineral density of the adult offspring. Obstetrics. Am J Obstet Gynecol 2013;20:443.e1-10

Weiler HA, Yuen CK, Seshia MM. Growth and bone mineralization of young adults weighing less than 1500g at birth. Early Hum Dev. 2001; 67: 101-12