What factors put you at risk?
Preeclampsia affects 5% to 10% of pregnancies worldwide. The rates, however, are lower in the United States at about 3% to 5% due to a more religious prenatal care program.
It is the most common complication that develops during pregnancy characterized by high blood pressure, the presence of protein in urine, swelling of hands, feet and the legs and damage to the body organs especially the kidneys.
The etiology and pathophysiology of preeclampsia have always been elusive. We still do not know what causes this condition.
Certain clinical risk factors that make you prone to preeclampsia during pregnancy are indentified but the etiology still remains elusive.
What are the conditions or factors that make some women more at risk of developing preeclampsia?
The first pregnancy, more so if it is multiple (twins) poses a high risk of developing preeclampsia. The chances of preeclampsia are significantly higher in the first than during subsequent pregnancies.
According to a study, the risk of pre-eclampsia was 4.1% in the first pregnancy and 1.7% in later pregnancies overall.
The incidence of pre-eclampsia associated with delivery prior to 34 weeks’ gestation was 0.42% in primiparous (first pregnancy) women.
Presence of preeclampsia in the first pregnancy makes you a very potential candidate for this complication in subsequent pregnancies.
History of preeclampsia in previous pregnancy:
Multiparous women with a history of pre-eclampsia in their previous pregnancies have a sevenfold increased risk of this condition in their next pregnancy.
According to the same study, the risk was 14.7% in the second pregnancy for women who had had pre-eclampsia in their first pregnancy and 31.9% for women who had had pre-eclampsia in the previous two pregnancies.
Secondly, the more severe the condition and the earlier it appears in the first pregnancy, the higher your risk in the next pregnancy.
For example, if you had severe preeclampsia that started before 29 weeks of previous pregnancy, your chances of getting it again may be nearly 40 percent, or perhaps more.
Gap between subsequent pregnancies
A study conducted by The New England Journal of Medicine concluded that the risk of preeclampsia during the second pregnancy was found to increase as the time interval since the first delivery increased
An increasing interval between the second and the third deliveries was similarly associated with a rising risk.
If there is a gap of at least ten years between the first and the second pregnancies, the chances of developing preeclampsia during the second pregnancy are almost tripled, almost reaching the level of the risk found among nulliparous women.
The first pregnancy with a new partner always has a higher chance of preeclampsia even if you have had a previous pregnancy with some other partner. The reason brought forward is a hypothesis.
Preeclampsia is believed to be the woman’s immunologic response to foreign fetal antigen derived from the father’s sperm.
Subsequent pregnancies with the same partner do not pose this risk. This is because the risk is reduced by prolonged exposure to father’s antigen, such as through a prior pregnancy, which is the reason why multiparas are typically at lower risk for preeclampsia than nulliparas.
The family history of preeclampsia in a mother, sister, or aunt will usually mean that you too, will carry on the tradition.
In a first-time mother, family history is associated with a fourfold increased risk of severe pre-eclampsia.
Obesity with a BMI of 30 or more is high risk factor. It is estimated that 30% of the preeclampsia risk is attributed to obesity.
In developed countries, however, obesity is the leading risk factor responsible for this disorder because obesity has reached alarming proportions in these countries.
Pregnancy before the age of 20 years and over 35 years increases the risk of preeclampsia.
The incidence of preeclampsia is increased by twofold in pregnant adolescence in comparison to women between ages 30-34. This is believed to be due to non-physiological related issues, such as the nulliparity (first pregnancy) and the lack of prenatal care.
Similarly, first time pregnancy in a woman of advanced maternal age (AMA) above 35 years is an independent risk factor of preeclampsia.
Women with AMA are more likely to be suffering from diabetes, hypertension and such chronic diseases, which make them more prone to develop this hypertensive pregnancy complication.
In Vitro Fertilization
Women who have conceived through in vitro fertilization (IVF) are at an increased risk of developing preeclampsia during pregnancy. The risk increases by 40%.
Researchers indicate that exposing embryos to laboratory conditions during IVF may lead to improper development of the placenta and its poor blood supply.
The egg may also lose its ability to implant itself successfully on the uterine wall.
Some health conditions
Women with kidney disease and diabetes, are at higher risk of developing preeclampsia during their pregnancy.
The incidence of preeclampsia is also seen to be higher in women who suffer from migraine headaches. Reason is not known.
Women with auto immune diseases such as systemic lupus erythematosus have a two-fold increase in their risk of preeclampsia
10% to 30% of the women with gestational diabetes develop preeclampsia. Like preeclampsia, gestational diabetes develops only during pregnancy.
Positive family history of hypertension and hypercholesterolemia
According to a study conducted by the US National Library of Medicine National Institutes of Health, severe preeclampsia is associated with a positive family history of hypertension and/or hypercholesterolemia.
For reasons unknown, AAfrican-American women in the United States are more prone to develop preeclampsia than white women.