When doctors talk about adverse pregnancy outcomes (APOs), they are referring to major problems that can develop for a pregnant woman, or for the fetus. APOs include various pregnancy complications, many of which we have discussed here on The Pulse. Examples of APOs include hypertensive (high blood pressure) disorders of pregnancy (gestational hypertension, preeclampsia, eclampsia, HELLP syndrome, and chronic hypertension with superimposed preeclampsia), gestational diabetes, preterm birth, fetal growth restriction, and various things that can go wrong with the placenta. When it comes to maternal complications in particular, we tend to focus on what they could mean for health and development of the newborn and on what they could mean for the short-term health for the mother, such as whether she will be in danger of losing her life during pregnancy or just after childbirth. But doctors and scientists have been studying also the maternal health effects of APOs in the weeks and months following delivery and throughout the lives of mothers.
Although, as we learned in a previous post about the 19th century Hungarian-Jewish physician Ignaz Semmelweis, that maternal mortality during and just after childbirth was extremely common before the understanding of germ theory came to life, childbirth fever is not an issue in modern, developed countries. Consequently, the absolute proportion of women dying in childbirth fortunately is much lower than it was centuries ago. It does occur, however, generally in mothers with high risk factors, such as heart disease. One simple measure of the severity of heart disease during pregnancy, but also throughout life is the New York Heart Association (NYHA) Functional Classification, which defines four classes. In Class I, you have heart disease, but no symptoms that would limit your normal activity. In Class II, there are mild symptoms, such as dyspnea (difficulty breathing) or angina (chest pain that comes and goes). If you have Class III heart disease, you are comfortable only when you rest, so your activity is limited. In Class IV, you suffer symptoms, even when resting and so activity is extremely limited and you must remain in bed.
High risk also is attached to older mothers. In the case of certain APOs, notably preeclampsia and eclampsia, the higher risk falls on both mothers who are older and those who are very young (teenage pregnancy). Pregnancy complications furthermore are much more likely to strike particularly women who are African American, Hispanic, and Asian.
But when scientists look at the numbers, they find that of the mothers who die on account of pregnancy complications, just approximately one third (31 percent) die during pregnancy, approximately another one third (36 percent) at delivery or within a week of it, and the remaining third (33 percent) from one week to one year after pregnancy. On top of this, researchers in certain areas of medicine such as neurology, cardiology, and endocrinology are finding that APOs can affect maternal health for much longer periods after childbirth. They actually have implications for the mother’s health throughout the rest of her life. Certain serious conditions, such as strokes (interruption of blood circulation in the brain), for example, are notorious for striking mostly older individuals. Yet, they are more likely to strike women in their forties and fifties with a history of preeclampsia in their twenties or thirties. The same goes for cardiovascular disease resulting from atherosclerosis, problems of the inner walls of arteries, which is most notorious for causing serious heart problems in older people, but which premenopausal women often keep in check. But they are more susceptible to it at younger ages, if they have suffered APOs. This situation also applies to type 2 diabetes, a very common, long-term medical condition characterized by decreased ability of body cells to pull sugar from the bloodstream in response to insulin.
Consequently, this post is to serve as an introduction to a new series that I’ll continue from time to time, focussing on such long-term health issues for mothers with APOs in their history. In this series we’ll discuss classes of diseases, such as coronary artery disease and other heart disease, diabetes, and cerebrovascular disease (disease of blood vessels supplying the brain, which can lead to stroke), that may be preventable during the years following pregnancy with an APO and the year when they begin to make women feel sick.
