One of the most common but most dangerous complications in pregnancy is metabolic toxemia of late pregnancy. This is also called Preeclampsia or Eclampsia depending on when symptoms present itself. 

Symptoms 

• Elevated Blood pressure (where previously the woman did not have high blood pressure)

• Protein in Urine 

• Generalised swelling beyond normal swelling in pregnancy

• Rapid weight gain 

• Changes in vision 

• Dizziness 

• Headaches

• Vomiting and Nausea 

Symptoms usually appear after 34 weeks of pregnancy. 

The most severe form of Eclampsia is when the placenta detaches itself from the uterine wall prematurely, endangering the baby, or seizures for the mother and death to the mother and baby. 

I wasn’t able to find any consistent statistics on how common preeclampsia is as it is so highly dependent on your specific circumstances. For example, it’s more common in a first pregnancy, if you have had a history of having it before. It is also more common for women who have a family history of preeclampsia, kidney disease, obesity or have a multiple pregnancy. 

Causes 

While doctors haven’t determined the exact cause for preeclampsia or eclampsia, its generally thought to be caused by poor nutrition, high body fat ratio or genetics. 

Risks 

Rupture of the placenta prior to birth, and seizures for the mother after birth with risk of potential death. Preeclampsia could also prevent the placenta from receiving the blood and nutrition it needs to feed the baby, leading to premature birth or problems with the baby such as learning disabilities, cerebral palsy or hearing and vision problems. It may also result in a stillbirth. 

Prevention 

According to Ina May Gaskin, Toxemia can be prevented by good nutrition and reducing stress. This means eating real food, not things out of a packet that have preservatives, additives. Avoid fizzy drinks and sweets, this includes fruit juice. Drink lots of water and eat plenty of protein. You can get protein from meat, dairy, legumes, nuts. Unlike doctors who told women to restrict their salt intake, she recommended women to salt their food however much they like. 

Treatment 

Doctors have historically not recognised the connection between good nutrition and toxemia, because doctors are not taught nutrition as part of their medical training. In the 1800s, Doctors treated Toxemia with bloodletting. In the 1930s and 1940s they recommended no salt starvation diets during pregnancy to prevent toxemia. In the 1960s and 70s they prescribed water pills as well to stop women from gaining more than 24 pounds during pregnancy. Ina may suggests that the techno-medical models favourite way to treat toxemia is by early delivery, either by induction of labour or planned c-section. In addition, many doctors prescribe magnesium sulfate, valium or calcium.  

Once women have Preeclampsia, the techno-medical model believes that the only way to treat it is to deliver the baby as soon as possible. Once you are 37 weeks pregnant, your doctor may suggest induction or a caesarean. The midwifery model however recommends prevention as the first treatment, by educating women on nutrition and improving the standard of prenatal care. 

Research 

There have been different theories about what causes preeclampsia or toxemia, which appears to be more common in first pregnancies than later pregnancies. Some have argued that its to do with the mother rejecting the mix of the fathers genes in the baby, as some studies have found that there is an increased risk in later pregnancies when there is a different partner fathering the child. Others have suggested that this has nothing to do with a different partner, but more to do with waiting years between children. To date, none of these correlations have been proven. 

Unfortunately it is very difficult to prove that nutrition has an effect in preventing toxemia as if you wanted to test it properly, you would need a control group where pregnant women are deliberately starved and suffer from malnutrition which would be extremely unethical. 

Dr. Thomas Brewer conducted a study which is the Contra costa county project in 1963 - 1976. He took a group of women - over 7000 mothers from low income groups in San Francisco, where the risk of toxemia for similar groups would have been 20 - 35%. By teaching the women about nutrition and counselling them through their pregnancy, they had a rate of toxemia that was only 0.5% and no cases of convulsive toxemia. 

https://midwiferytoday.com/mt-articles/preventing-complications-nutrition/