However, the damaging effects of smoking on overall health and pregnancy outcomes outweighs the benefits in decreasing the incidence of pre-eclampsia. It is recommended that smoking be stopped prior to, during and after pregnancy. Immune modulation
Some studies have suggested the importance of a womans gestational immunological tolerance to her babys father, as the baby and father share genetics. There is tentative evidence that ongoing exposure either by vaginal or oral sex to the same semen that resulted in the pregnancy decreases the risk of pre-eclampsia. As one early study described, "although pre-eclampsia is a disease of first pregnancies, the protective effect of multiparity is lost with change of partner". The study also concluded that although women with changing partners are strongly advised to use condoms to prevent sexually transmitted diseases, "a certain period of sperm exposure within a stable relation, when pregnancy is aimed for, is associated with protection against pre-eclampsia".Several other studies have since investigated the decreased incidence of pre-eclampsia in women who had received blood transfusions from their partner, those with long preceding histories of sex without barrier contraceptives, and in women who had been regularly performing oral sex.Having already noted the importance of a womans immunological tolerance to her babys paternal genes, several Dutch reproductive biologists decided to take their research a step further.
In the absence of proteinuria, the presence of new-onset hypertension (elevated blood pressure) and the new onset of one or more of the following is suggestive of the diagnosis of pre-eclampsia:
Evidence of kidney dysfunction (oliguria, elevated creatinine levels)
Impaired liver function (noted by liver function tests)
Thrombocytopenia (platelet count <100,000/microliter)
Pulmonary edema
Ankle edema (pitting type)
Cerebral or visual disturbancesPre-eclampsia is a progressive disorder and these signs of organ dysfunction are indicative of severe pre-eclampsia. A systolic blood pressure ≥160 or diastolic blood pressure ≥110 and/or proteinuria >5g in a 24-hour period is also indicative of severe pre-eclampsia. Clinically, individuals with severe pre-eclampsia may also present epigastric/right upper quadrant abdominal pain, headaches, and vomiting. Severe pre-eclampsia is a significant risk factor for intrauterine fetal death. A rise in baseline blood pressure (BP) of 30 mmHg systolic or 15 mmHg diastolic, while not meeting the absolute criteria of 140/90, is important to note but is not considered diagnostic. Predictive tests
There have been many assessments of tests aimed at predicting pre-eclampsia, though no single biomarker is likely to be sufficiently predictive of the disorder. Predictive tests that have been assessed include those related to placental perfusion, vascular resistance, kidney dysfunction, endothelial dysfunction, and oxidative stress. Examples of notable tests include:

Doppler ultrasonography of the uterine arteries to investigate for signs of inadequate placental perfusion. This test has a high negative predictive value among those individuals with a history of prior pre-eclampsia.