Maternal Physiologic Complications of Pregnancy
Maternal physiologic complications of pregnancy are the medical disorders that arise in, or are aggravated by, the pregnant state and that threaten the health of the mother. They span disturbances of glucose metabolism, blood pressure, coagulation, haemostasis, and host defence, and together they account for a large share of maternal morbidity and death worldwide.
Definition
Maternal physiologic complications of pregnancy are deviations from normal maternal physiology that occur during gestation, delivery, or the puerperium and that endanger the health of the pregnant or recently pregnant person, conventionally grouped with the broad MeSH heading Pregnancy Complications.
Scope
This area orients the reader to the principal pregnancy-related disorders of maternal physiology grouped in this branch: gestational and pregestational diabetes, hypertensive disorders of pregnancy, venous thromboembolism, antepartum and obstetric haemorrhage, and infection and sepsis. It frames how the adaptations of normal pregnancy create vulnerability to these conditions and points to the dedicated topic entries for detail; it does not address fetal anomalies or the conduct of labour as such.
Sub-topics
Core questions
- How do the normal physiological adaptations of pregnancy predispose to metabolic, vascular, haemostatic, and infectious complications?
- Which conditions contribute most to maternal morbidity and mortality, and how does this differ between high- and low-income settings?
- How are pregnancy-specific complications distinguished from pre-existing maternal disease that worsens in pregnancy?
- Why does severe maternal morbidity persist, and how is it distributed across populations?
Key concepts
- Physiological adaptation of pregnancy
- Maternal morbidity and mortality
- Severe maternal morbidity
- Pregnancy-specific versus pre-existing disease
- Direct versus indirect maternal death
- Hypercoagulability of pregnancy
- Placental and systemic vascular dysfunction
Mechanisms
Normal pregnancy involves wide-ranging physiological change: insulin resistance rises to divert glucose to the fetus, plasma volume and cardiac output expand, systemic vascular resistance falls, and the haemostatic system shifts toward a procoagulant, hypercoagulable state while immune tolerance of the fetus is established. Each adaptation carries a corresponding vulnerability. Insufficient insulin secretion against rising resistance produces gestational diabetes; abnormal placentation and endothelial dysfunction underlie hypertensive disorders; the procoagulant shift raises thromboembolic risk; the large uteroplacental circulation makes haemorrhage rapid and severe; and altered immunity together with instrumented delivery and tissue injury raises susceptibility to infection and sepsis. These mechanisms are developed in the individual topic entries.
Clinical relevance
These complications are central to obstetric and maternal-medicine practice and to the global agenda on maternal health, since haemorrhage, hypertensive disorders, sepsis, and thromboembolism are leading direct causes of maternal death. This area provides an orienting reference framework for how the disorders relate to one another and to normal pregnancy physiology; it describes the conditions and is not a source of dosing or individualised treatment recommendations.
Epidemiology
A WHO systematic analysis attributed the largest shares of global maternal deaths to haemorrhage, hypertensive disorders, and sepsis, with substantial contributions from indirect (pre-existing or aggravated) causes and from thromboembolism in higher-income settings (Say and colleagues, 2014). In the United States, pregnancy-related mortality and severe maternal morbidity have been tracked through national surveillance and shown to be unevenly distributed, with marked racial and ethnic disparities (Berg and colleagues, 2010; Admon and colleagues, 2018).
Evidence & guidelines
The conditions grouped here are addressed by major obstetric and maternal-medicine guidelines and by global health analyses; this overview cites population-level evidence (Say and colleagues, 2014; Berg and colleagues, 2010; Admon and colleagues, 2018) and a critical-care review (Williams and Mozurkewich, 2008), while condition-specific guidance is summarised in the linked topic entries.
History
Concern with maternal complications is as old as obstetrics, but systematic measurement is a twentieth- and twenty-first-century achievement: confidential enquiries into maternal deaths, national surveillance of pregnancy-related mortality, and global burden estimates progressively defined the leading causes and revealed persistent inequities, reframing many complications as largely preventable.
Related topics
Seminal works
- say-2014
- berg-2010
Frequently asked questions
- What counts as a maternal physiologic complication of pregnancy?
- It is a medical disorder of maternal physiology, such as a metabolic, vascular, haemostatic, or infectious disturbance, that arises during pregnancy, delivery, or the puerperium, or a pre-existing condition that worsens because of pregnancy.
- Which maternal complications cause the most deaths worldwide?
- Global analyses identify haemorrhage, hypertensive disorders, and sepsis as leading direct causes of maternal death, alongside indirect causes and, especially in higher-income settings, thromboembolism.