The Mayo Clinic states that hypertension during pregnancy can fall into two different categories: gestational hypertension or chronic hypertension. The effects on the baby will depend on the type of hypertension that is present. It is possible for severe, persistent high blood pressure to lead to significant complications for an unborn baby, as well as the mother. If a woman has a history of high blood pressure or develops high blood pressure during pregnancy, her doctor will monitor her closely until the baby is born.
When a woman suffers hypertension, the baby will be suffering as well. In order to keep the baby safe, doctors will usually make arrangements to deliver the baby earlier than the normal 40 weeks. Doctors may decide to deliver the baby between 34 weeks and 37 weeks to keep the baby from suffering the severe effects preeclampsia can bring. It is possible that the baby could stop developing past this point because of the hypertension, so early delivery is deemed safer for the baby and for the mother. Most often the doctor will try to let the mother carry the child until 37 weeks gestation so the baby can develop further and have a lower risk for complications.
Low Birth Weight
Hypertension during pregnancy causes the blood vessels that carry blood to the placenta to become more narrow, states the March of Dimes. The problem with this is it keeps the unborn baby from receiving the nutrients it should. The unborn baby will then have problems growing or gaining weight, which is called restricted fetal growth. Unless the hypertension is controlled, this can cause the baby to be significantly underweight at birth, which can cause medical complications in the future. Luckily, it is possible to control hypertension and prevent this complication.
Preeclampsia is a medical condition caused by hypertension in pregnant women. The pregnant woman will develop protein in the urine. Preeclampsia is a precursor to eclampsia, which is a more severe occurrence of high blood pressure. Eclampsia can cause seizures in the mother and can even be fatal. The National Heart Lung and Blood Institute states that preeclampsia is only diagnosed after 20 weeks gestation.
Placental abruption is a serious problem caused by untreated cases of hypertension. The placenta will separate itself from the wall of the uterus, causing internal bleeding in the pregnant woman. It can also rob the unborn baby of oxygen. Because the baby is in significant danger when this happens, immediate delivery is necessary.
March of Dimes: High Blood Pressure During Pregnancy - https://www.marchofdimes.com/professionals/14332_1222.asp
National Heart Lung And Blood Institute: High Blood Pressure in Pregnancy - https://www.nhlbi.nih.gov/health/public/heart/hbp/hbp_preg.htm
Mayo Clinic: High Blood Pressure and Pregnancy - https://www.mayoclinic.com/health/pregnancy/PR00125