Pregnancy is a time in which a woman's body changes drastically--not only the outward shape as the developing baby grows, but her internal system as well. Blood volume increases and blood pressure may rise to accommodate the additional fluids. Glucose levels may rise as well. Levels of cholesterol -- a substance that aids in digestion and helps make hormones and vitamin D -- may also be affected during pregnancy.
Normal Cholesterol Levels
According to the American Association for Clinical Chemistry -- AACC, cholesterol levels for the non-pregnant population should be below 200 mg/dL to keep your risk of heart disease low. Cholesterol levels are considered borderline high between 200 and 239 mg/dL and high at 240 mg/dL or higher. Pregnancy can cause your previously normal cholesterol levels to rise; this is a normal development that is not necessarily cause for alarm. Your doctor will determine whether your readings put you at risk for health problems during the course of your pregnancy.
Low Cholesterol and Pregnancy
Women who have low cholesterol prior to conception and during their pregnancy may have an increased risk of premature labor and other pregnancy-related problems. The AACC defines low cholesterol as less than 100 mg/dl. The National Institutes of Health --NIH -- studied women with lower cholesterol -- the participants studied measured an average of 159 mg/dl -- and found that they were more likely to give birth prematurely. The incidence of preterm birth was significantly higher among white women than those of color, for reasons that were not stated in the study. The NIH reports that cholesterol is essential for the development of a healthy placenta; not enough cholesterol in the mother's body may hamper fetal development leading to low birth weight and a smaller head circumference.
High Cholesterol Risks in Pregnancy
High cholesterol levels can cause some risks during pregnancy. Women who had high cholesterol before becoming pregnant--as opposed to the normal rise in cholesterol during the gestation period--have a heightened risk of preterm birth, according to the NIH. The March 1999 issue of the "American Journal of Hypertension" discusses correlation between high maternal cholesterol levels and pregnancy-induced hypertension, a state of high blood pressure brought on by pregnancy. The study found that pregnant women who had elevated cholesterol levels of 279 mg/dL and raised insulin levels were more likely to develop pregnancy-induced hypertension, or PIH. PIH is a potentially dangerous condition that can threaten the life of both mother and infant. The only treatment for PIH is delivery of the baby.
Statin Drugs in Pregnancy
Statin drugs are the class of medications used to lower high cholesterol levels. In some cases, an expectant mother's cholesterol levels may creep up to a point at which both she and her baby may be at risk for heart disease. In November 2007, the "Journal of Obstetrics and Gynaecology Canada" published a review of studies that discuss the risks of use of statin drugs during pregnancy. Neither animal nor human research showed teratogenic effects of the drugs when used at normal doses. Higher doses of some statin medications that would cause toxicity in the mother showed corresponding harmful effects in fetal animal testing. Recommendations for statin drug use during pregnancy remain, like other medications, that the benefits of medicating should significantly outweigh the risks to both mother and baby.
If pregnant women were prescribed statin drugs as needed to control high cholesterol, the need for caesarean section births would decrease. Liverpool University studies show that high cholesterol can inhibit uterine contractions, stalling the birth process and requiring surgical intervention.
High cholesterol levels associated with pregnancy most often resolve themselves within the first few weeks after birth, according to the AACC. The organization recommends waiting at least six weeks postpartum before performing cholesterol testing to get an accurate reading. Women who still have high cholesterol should consult their doctors to determine the best course for reducing their total cholesterol levels and decreasing associated health risks.
Is This an Emergency?
- Lab Tests Online: Cholesterol
- American Journal of Hypertension: Higher Cholesterol and Insulin Levels in Pregnancy Are Associated With Increased Risk for Pregnancy-Induced Hypertension
- Journal of Obstetrics and Gynaecology Canada: Risks of Statin Use During Pregnancy: A Systematic Review
- Reuters: Low Cholesterol May Raise Preterm Birth Risk
- Pediatrics: Adverse Birth Outcome Among Mothers With Low Serum Cholesterol