[177-POS]: Seasonality of pregnancy induced hypertensive disorders in South Australia - A retrospective population study 2007-2011.
Pregnancy Hypertens. 2015 Jan;5(1):91. doi: 10.1016/j.preghy.2014.10.183. Epub 2015 Feb 23.
Verburg PE1, Tucker G2, Scheil W2, Erwich JJ1, Roberts CT3, Dekker GA3.
4 years, 4252 pregnancies,
7% had pregnancy induced hypertensive disorders (PIHD, which leads to preeclampsia)
To assess the seasonal variation of pregnancy induced hypertensive disorders (PIHD) in an Australian population.
Retrospective study of 59,993 South Australian singleton live born births, for whom a body mass index (BMI) of the mother and sex of the baby were recorded, during 2007-2011 in the South Australian Perinatal Statistics Collection. The incidence of PIHD in relation to birth date was assessed. Fourier series analysis was used to model seasonal trends.
Of a total of 59,993 births recorded during the study period 4252 (7.1%) women were diagnosed with PIHD. Seasonal modelling showed a strong relation between PIHD and date of birth (p<0.000). When adjusted for confounders (age, BMI, race, smoking during second half of pregnancy, parity and gestational diabetes) the model still showed a strong relation between PIHD and date of birth (p<0.000). The peak prevalence occurred among births in Winter (Jun/Jul/Aug), with a trough in pregnancies with birth in (late-) Summer (Jan/Feb).
These epidemiological data support seasonal periodicity for PIHD in an Australian population. The highest incidence of PIHD was associated with birth in the Winter months (Jun/Jul/Aug). The etiology of PIHD is still elusive, but theories include
- genetic and immune mechanisms,
- (abnormal placentation
- cardiovascular maladaptation to pregnancy,
- nutritional, hormonal and angiogenetic factors and
- enhanced systemic inflammatory response.
Recent studies found a relation between both infection and low maternal vitamin D levels and pre-eclamspia. These conditions could explain the detected seasonality for PIHD. Further investigation into the biological mechanism(s) for this finding should be undertaken to identify additional risk factors, so PIHD can be prevented in the clinic.
|IU||Cumulative Benefit||Blood level||Cofactors||Calcium||$*/month|
|200|| Better bones for mom|
with 600 mg of Calcium
|6 ng/ml increase||Not needed||No effect||$0.10|
|400|| Less Rickets (but not zero with 400 IU)|
3X less adolescent Schizophrenia
Fewer child seizures
|20-30 ng/ml||Not needed||No effect||$0.20|
|2000|| 2X More likely to get pregnant naturally/IVF |
2X Fewer dental problems with pregnancy
8X less diabetes
4X fewer C-sections (>37 ng)
4X less preeclampsia (40 ng vs 10 ng)
5X less child asthma
2X fewer language problems age 5
|42 ng/ml||Desirable||< 750 mg||$1|
|4000|| 2X fewer pregnancy complications |
2X fewer pre-term births
|49 ng/ml|| Should have |
|< 750 mg||$3|
|6000||Probable: larger benefits for above items|
Just enough D for breastfed infant
More maternal and infant weight
|< 750 mg||$4|