Hypertension in pregnancy

Pregnancy associated with certain high risk factors carries more risk to the developing fetus as well as the mother. These pregnancies require more vigilance and care and are called as High Risk Pregnancy.


  • Mother has anaemia, high blood pressure, heart diseases, diabetes, multiple pregnancies, women over the age of 40 years, previous caesarean deliveries, previous miscarriages etc

  • The fetus may have IUGR / FGR (growth restriction), less fluid around the baby (oligohydroamnios), more fluid around the baby (polyhydroamnios) etc


  • High BP (blood pressure) which develops during the pregnancy is called pregnancy induced hypertension (PIH), which in severe cases can cause PRE ECLAMPSIA.

  • Some women have high BP prior to conceiving, this is called chronic hypertension. Women with chronic hypertension may already be on drugs while conceiving. Such women must visit the obstetrician prior to conception as certain medications used for controlling BP may not be good for the baby. We generally shift the women to another drug which can control the BP and also not harm the developing baby. These mothers may develop swelling of the feet, headache, increase in BP etc later during their pregnancies knowing as superimposed Pregnancy induced hypertension or pre eclampsia.

  • About 1 in 10 pregnant women has problems with high blood pressure.

  • If you are pregnant you should have regular blood pressure checks.

  • Most women will not develop any problems with their blood pressure during pregnancy. However, in some women, high blood pressure can develop. It is often mild and not serious. But in some cases, high blood pressure can become severe and can be harmful to both the mother and baby.

  • Some women can develop new high blood pressure during their pregnancy. This is called pregnancy-induced high blood pressure (or hypertension) or gestational high blood pressure (or hypertension).

  • Gestational high blood pressure is high blood pressure that develops for the first time after 5 months of pregnancy. Women with a family history of hypertension or history of PIH in previous pregnancies have a higher incidence of developing it. Also women who are overweight or obese prior to pregnancy and women who tend to gain too much weight during pregnancy are at high risk of developing PIH.

  • These women are also at risk for developing growth restriction in the baby (IUGR/FGR). These babies may have low birth weight due to deficient blood supply through the placenta.

  • Therefore these women and pregnancies should be monitored more strictly and vigilantly.


  • Rhesus (Rh) incompatibility refers to the discordant pairing of maternal and fetal Rh type.
  • This leads to maternal Rh sensitization and hemolytic disease of the neonate (HDN).
  • A person has Rh positive blood group if her erythrocytes (blood cells) express the Rh D antigen. If this anitgen is not expressed they are called Rh-negative.
  • If the mother has Rh negative blood group and becomes sensitized to the D antigen and subsequently, produces anti-D antibodies (i.e., alloimmunization) they can bind to and potentially lead to the destruction of Rh-positive erythrocytes.
  • This is extremely important if a Rh-negative mother is carrying a Rh-positive fetus, which can result in HDN. This can be self-limited hemolytic anemia to severe hydrops fetalis.
  • However, if the exposure to the Rh D antigen occurs during the mother’s first pregnancy, the adverse consequences of Rh incompatibility do not typically affect that initial pregnancy because the fetus often is delivered before the development of the anti-D antibodies.
  • However, as the mother has been sensitized, future pregnancies are at risk for the development of HDN secondary to Rh incompatibility if the fetus is Rh-positive.
  • It is strongly recommended to do a Rh(D) blood type and antibody screen for all pregnant women at the initial prenatal visit. Immunoprophylaxis via RhIg is of value when alloimmunization has not yet occurred. 
  • The main principles of the management of Rh incompatibility is the prevention of maternal sensitization. 
  • Following birth, ABO and Rh D typing should be performed on cord blood and if the baby is confirmed to be D positive, all D negative, previously non‐sensitised, women should be offered at least 500 IU of anti‐D Ig within 72 h following delivery.



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