Risk factors

High Blood Pressure in Pregnancy ⁽¹⁸⁾

What Are the Effects of High Blood Pressure in Pregnancy?

Although many pregnant women with high blood pressure have healthy babies without serious problems, high blood pressure can be dangerous for both the mother and the fetus. Women with pre-existing, or chronic, high blood pressure are more likely to have certain complications during pregnancy than those with normal blood pressure. However, some women develop high blood pressure while they are pregnant (often called gestational hypertension).

The effects of high blood pressure range from mild to severe. High blood pressure can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery. In the most serious cases, the mother develops preeclampsia – or „toxemia of pregnancy“ – which can threaten the lives of both the mother and the fetus.

What Is Preeclampsia?

Preeclampsia is a condition that typically starts after the 20th week of pregnancy and is related to increased blood pressure and protein in the mother's urine (as a result of kidney problems). Preeclampsia affects the placenta, and it can affect the mother's kidney, liver, and brain. When preeclampsia causes seizures, the condition is known as eclampsia–the second leading cause of maternal death in the U.S. Preeclampsia is also a leading cause of fetal complications, which include low birth weight, premature birth, and stillbirth.

There is no proven way to prevent preeclampsia. Most women who develop signs of preeclampsia, however, are closely monitored to lessen or avoid related problems. The only way to „cure“ preeclampsia is to deliver the baby.

How Common Are High Blood Pressure and Preeclampsia in Pregnancy?

High blood pressure problems occur in 6 percent to 8 percent of all pregnancies in the U.S., about 70 percent of which are first-time pregnancies. In 1998, more than 146,320 cases of preeclampsia alone were diagnosed.

Although the proportion of pregnancies with gestational hypertension and eclampsia has remained about the same in the U.S. over the past decade, the rate of preeclampsia has increased by nearly one-third. This increase is due in part to a rise in the numbers of older mothers and of multiple births, where preeclampsia occurs more frequently. For example, in 1998 birth rates among women ages 30 to 44 and the number of births to women ages 45 and older were at the highest levels in 3 decades, according to the National Center for Health Statistics. Furthermore, between 1980 and 1998, rates of twin births increased about 50 percent overall and 1,000 percent among women ages 45 to 49; rates of triplet and other higher-order multiple births jumped more than 400 percent overall, and 1,000 percent among women in their 40s.

Who Is More Likely to Develop Preeclampsia?

Women with chronic hypertension (high blood pressure before becoming pregnant)
Women who developed high blood pressure or preeclampsia during a previous pregnancy, especially if these conditions occurred early in the pregnancy
Women who are obese prior to pregnancy
Pregnant women under the age of 20 or over the age of 40.
Women who are pregnant with more than one baby
Women with diabetes, kidney disease, rheumatoid arthritis, lupus, or scleroderma

How Is Preeclampsia Detected?

Unfortunately, there is no single test to predict or diagnose preeclampsia. Key signs are increased blood pressure and protein in the urine (proteinuria). Other symptoms that seem to occur with preeclampsia include persistent headaches, blurred vision or sensitivity to light, and abdominal pain.

All of these sensations can be caused by other disorders; they can also occur in healthy pregnancies.

Risk factors for depressive symptoms during pregnancy⁽¹⁷⁾

Depression is one of the most commoncomplications in pregnancy. As many as 12.7% of pregnant women experience a major depressive disorder. Several professional organizations now recommend routine screening for antepartum depression. In fact, the American College of Obstetricians and Gynecologists (ACOG) recommends screening for depression during each trimester of pregnancy.

The purpose of this study was to evaluate risk factors for antepartum depressive symptoms that can be assessed in routine obstetric care. We evaluated articles in the Englishlanguage literature from 1980 through 2008. Studies were selected if they evaluated the association between antepartum depressive symptoms and ≥1 risk factors. For each risk factor, 2 blinded, independent reviewers evaluated the overall trend of evidence. In total, 57 studies met eligibility criteria. Maternal anxiety, life stress, history of depression, lack of social support, unintended pregnancy, Medicaid insurance, domestic violence, lower income, lower education, smoking, single status, and poor relationship quality were associated with a greater likelihood of antepartum depressive symptoms in bivariate analyses. Life stress, lack of social support, and domestic violence continued to demonstrate a significant association in multivariate analyses. Results demonstrate several correlates that are consistently related to an increased risk of depressive symptoms during pregnancy

Results

A total of 159 articles met inclusion criteria (Figure). Studies were most often excluded because they did not assess predictors for depression (n = 55) or they presented only postpartum data (n = 45). A table of the excluded articles is available by request from the corresponding author (C.A.L.).

The 159 included articles had a mean sample size of 522 subjects (SD = 1014; median = 175). Approximately half (54.1%) of the studies were performed in the United States. Seventeen studies (10.7%) were longitudinal in design, and 52 studies (32.7%) included multivariate analysis. The 159 studies used 24 different depression screeners, with the Center for Epidemiological Studies Depression Scale (31.4%), the Edinburgh Postnatal Depression Scale (18.2%), and the Beck Depression Inventory (17.0%) being the most common. Only 20 studies (12.6%) used a formal diagnostic assessment for depression.

Overall, the mean study quality score was 6.3 (SD = 1.1). Due to the large number of studies and heterogeneity of study designs, we limited our analysis to the top 25th percentile of quality scores (≥7). In addition, to reach a score of 7, studies must have addressed quality items involved in both internal and ex-ternal validity. A total of 57 studies met this quality cutoff (hereafter referred to as “high-quality studies”) and are presented in Table 1. We included 20 potential predictor variables for antepartum depressive symptoms. Table 2
displays the overall trend of association for each potential risk factor.

Comment

In summary, our results highlight several important correlates of depressive symptoms during pregnancy, including maternal anxiety, life stress, prior depression, lack of social support, domestic violence, unintended pregnancy, relationship factors, and public insurance. Life stress, lack of social support, and domestic violence continued to be associated with antepartum depressive symptoms in multivariate analyses. In general, our findings regarding antepartum depression are consistent with those of previous metaanalyses that evaluated postpartum depression. However, while 2 of the postpartum metaanalyses found an association between SES and postpartum depression, our review showed no association between composite SES measures and antepartum depression. This disparity could be due to the fact that their metaanalyses evaluated risk factors for postpartum depression, while our review focused on risk factors for depression during pregnancy. Also, the studies in our sample tended to compare SES within homogeneous patient populations. The lack of variability within each study sample could have decreased the power to detect an association. In addition, the power of our review to detect an association was limited by the fact that we did not use metaanalytic techniques. Third, the lack of an association between SES and antepartum depression may be due to true mediators that explain this phenomenon, such as chronic stress. Finally, SES may not be directly associated with antepartum depressive symptoms, but it may moderate the relationship between other risk factors and depression during pregnancy.

Maternal anxiety

In the general population, depression and anxiety are highly comorbid, with almost 60% of individuals with major depression also meeting criteria for an anxiety disorder. In this review, 11 studies evaluated the relationship between maternal anxiety and depression. Anxiety showed one of the strongest associations with antepartum depressive symptoms. On average, anxiety during pregnancy had a medium-tolarge correlation with depressive symptoms in bivariate analysis.