What do we mean by maternal mortality and morbidity?

MEGAN KILL: So in this week, we’re looking at the public health issues around safe motherhood. And in this particular step, we’ll describe the terminology that’s frequently used in the maternal health field. So pregnancy-related complications are a problem everywhere, and particularly so in poorer countries, where they are among the leading causes of death and disability for women aged 15 to 49. And safe motherhood it’s not just a medical problem, but it’s also a public health problem. And we need to ensure that all women receive safe, healthy, and respectful care throughout pregnancy and childbirth. Maternal mortality refers to deaths around the time of pregnancy.

And according to the last update of the International Classification of Diseases 9 and 10, maternal death is defined as the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by pregnancy or management, but not from accidental or incidental causes. Now just note the time frame, which is 42 days, as we’ll come back to it later. And also note that accidental and incidental causes are excluded from maternal deaths. Now, an accidental death can refer to something as in a car crash. And an incidental death could be a death from cancer, not related or aggravated by pregnancy.

And maternal death is also divided into two groups, direct and indirect. So in practise, we speak about maternal death. But there’s also the concept of pregnancy-related deaths, where we do not know the exact cause of death. And this can be useful in settings where the health information system is weak and where maternal deaths are captured principally through surveys of the population. Direct deaths are complications that only exist in pregnant women or women who are in labour. And they mainly include preeclampsia, eclampsia, obstetric haemorrhage, puerperal sepsis and prolonged or obstructed labour. Unanticipated complications of management of other illnesses fall under this category as well. And these can be things such as suicide in pregnancy, postpartum depression, things like that.

Now, indirect obstetric deaths include deaths from diseases that already existed before pregnancy or which developed during pregnancy, but are not specific to pregnant women and are aggravated by pregnancy. So indirect obstetric conditions can include cardiac disease, HIV, malaria, some psychiatric disorders. So indicators of maternal mortality reflect distinct probabilities– the probability of getting pregnant and the probability of dying once pregnant. So clearly, you cannot die of a maternal death if you’re not pregnant in the first place. The most frequently used indicator is the maternal mortality ratio. And this is otherwise known as the obstetric risk. So this measures the probability of death once pregnant and it’s often expressed per 100,000 live births.

So an example of this, say, in Uganda in 2010, they estimated to be 310 maternal deaths per 100,000 live births was the maternal mortality ratio. Now, the maternal mortality rate is different. It’s another indicator used. And it’s defined by the number of maternal deaths in a given period per number of women of reproductive age during the same period. So this is not as oftenly used as maternal mortality ratio, as we tend not to have the information to produce this figure. But then the lifetime risk, which measures the probability of a 15-year-old woman dying from a maternal cause at some point in her lifetime.

And this takes into account the number of times the woman is exposed to the risk, or in other words, the number of times the woman falls pregnant and her risk of dying in any given pregnancy. So for example, again in Uganda, women have on average six children. And there’s a high MMR or obstetric risk. So their lifetime risk is 1 in 49. So in other words, for every 49 women, one will die of maternal causes.

Now, as maternal mortality is declining, there’s a stronger interest in understanding maternal morbidity. So in 2013, the WHO Maternal Morbidity Working Group redefined maternal morbidity as “any health condition attributed to or complicating pregnancy, childbirth, or following pregnancy that has a negative impact on the woman’s wellbeing or functioning.” Now, note there’s no defined time period for maternal morbidity and that the negative impact of a complication could last much longer than 42 days as the maternal mortality definition is. So the other things I want to point out is that the terms “wellbeing” and “health-related functioning” in the definition refers to body functions, activities and participation– so for example, the ability to work or have social interaction.

And wellbeing also reflects the satisfaction, expectations, and aspirations. So there are different pathways that pregnancies can take. Now, this diagram shows how pregnancy can lead to morbidity, death, and near-misses. Now, most women have uncomplicated pregnancies, deliveries, and postpartum periods and have no adverse outcomes. Some will have complications which can range from complicated to severely complicated or life-threatening. And these types of complications can lead to morbidity. Now, if a woman has a life-threatening complication, they can either die or survive. If they survive, then it’s termed a near-miss. So a near-miss has a really important concept in safe motherhood, because there are many more near-misses than deaths and it helps for evaluation of programmes, as maternal death is quite a rare event.

And it can be complex to capture in the field. So as we talk about with mortality, there are also different morbidity indicators. And I have listed a few examples of common morbidity indicators below, but there are more used. So the point prevalence morbidity refers to morbidity episodes at a point in time divided by the number of pregnant or postpartum women at that point in time. And this indicator is quite useful for planning services. The maternal near-miss ratio refers to the number of maternal near-miss cases per 1,000 live births. And it’s mostly obtained from hospital data. The mortality index refers to the number of maternal deaths divided by the number of women with life-threatening complications.

And this can be used as a measure of quality of care.