B1513 - Do hypertensive disorders and anaemia in pregnancy increase the risk of respiratory and atopic diseases in childhood - 14/02/2013
Background:
We have previously found a negative association between umbilical cord iron concentration and early childhood eczema in ALSPAC[1], but associations between maternal anaemia and childhood atopic outcomes have not been reported. Other studies have reported that maternal hypertension in pregnancy is associated with impaired infant lung function[2] and, along with preeclampsia, with an increased risk of early childhood wheezing[3], but data are lacking on whether these conditions predict asthma and impaired lung function later in childhood. It would be interesting to know whether any effects of maternal hypertension/preeclampsia on these outcomes are mediated through lower birth weight and whether preeclampsia might explain any of the well-known birth order/parity association with atopy. Clearly, if anaemia and maternal hypertension/preeclampsia are causes of childhood asthma and atopy there may be important opportunities for primary prevention.
Aims:
To analyse the associations between maternal anaemia and hypertensive disorders of pregnancy and respiratory and atopic outcomes in the offspring.
Hypotheses:
* Anaemia is associated with increased risk of atopic disease
* Hypertension and preeclampsia are associated with increased risk of asthma and impaired lung function.
Variables needed for primary analyses:
Derived exposure variables of interest:
* Hypertensive disorder of pregnancy (gestational hypertension plus preeclampsia)
* Preeclampsia
* Gestational hypertension
* Pre-existing hypertension
* Early pregnancy Hb
Confounders and outcomes: We have all potential confounder variables with the exception of gestational weight gain. Outcomes will include asthma, hayfever, eczema, atopy and total IgE at 7 years, and lung function at 8-9 years (we have these variables too).
If we confirm associations with hypertension it might be of interest to carry out secondary analyses to explore associations with changes in blood pressure at different stages of gestation using the appropriate derived variables.