Diabetes and Pregnancy

Slide 1 · Diabetes and Pregnancy

Pathogenesis, maternal–fetal consequences, and longitudinal risk

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Distinguish pregestational from gestational diabetes by clinical chronology.

Explain why pregnancy can expose susceptibility to impaired glucose tolerance.

Relate maternal glycemia and timing of exposure to reported fetal outcomes.

Interpret postpartum resolution and subsequent diabetes risk without conflating them.

Slide 3 · Two settings for diabetes during pregnancy

Pregestational diabetes

Diabetes exists before conception.

The pregnancy occurs in a person already affected by diabetes.

The source also describes this as “overt” diabetes.

Gestational diabetes

The individual was previously euglycemic.

Impaired glucose tolerance or diabetes first develops during pregnancy.

The pregnancy-related metabolic setting is central.

Slide 4 · Define the phenotype by chronology

Question

Pregestational

Gestational

Before pregnancy

Diabetes already present

Previously euglycemic

During pregnancy

Preexisting diabetes complicates gestation

Dysglycemia appears for the first time

Typical postpartum course

Not defined by pregnancy-limited onset

Usually resolves after delivery

Chronology distinguishes the two settings; Glucose elevation can affect either.

Slide 5 · Diabetes type and pregnancy timing are separate axes

Underlying diabetes biology

Timing relative to conception

Pregnancy phenotype

Type 1 and type 2 describe differing mechanisms of diabetes.

Pregestational versus gestational specifies the relationship to pregnancy.

Do not equate “gestational” with a particular type 1 or type 2 mechanism.

Slide 6 · Think in windows of exposure

Before conception

Possible established diabetes

During gestation

Diabetes or new intolerance

After delivery

Resolution or persistence

A pregnancy can begin with diabetes already present.

Alternatively, glycemic intolerance can arise as pregnancy progresses.

Postpartum behavior is informative but does not erase prior exposure.

Slide 7 · Hyperglycemia affects a substantial minority of pregnancies

5%–9%

Approximate share of U.S. Pregnancies reported as complicated by hyperglycemia.

This range covers both pregestational and gestational diabetes.

It is a textbook-reported U.S. Estimate, not a universal or live surveillance rate.

Prevalence depends on population and ascertainment.

Slide 8 · Both forms have been increasing

An increasing incidence of gestational diabetes.

The same statement applies to pregestational diabetes in pregnancy.

Do not assume that the relative contribution of each category is constant.

The passage supplies no trend slope or year-specific time series.

Slide 9 · Pregnancy is a diabetogenic state

Pregnancy hormonal milieu

Increased insulin resistance

Greater glycemic demand

The normal hormonal environment of pregnancy favors resistance to insulin.

Increased resistance raises the physiological demand for effective insulin action.

Metabolic stress alone does not imply that diabetes occurs in every pregnancy.

Slide 10 · From resistance to hyperglycemia: Conditional pathway

Gestational insulin resistance

Susceptible metabolic background

Impaired glucose tolerance

The first component is the physiological context of pregnancy.

The second reflects additional genetic and environmental factors.

Only their interaction may lead to gestational dysglycemia.

Conceptual integration of the supplied pregnancy paragraph.

Slide 11 · Why many pregnancies remain euglycemic

A physiological challenge

Pregnancy tends to increase insulin resistance.

Insulin resistance is not identical to hyperglycemia.

Glucose balance depends on an adequate response to demand.

A susceptible individual

Genetic and environmental influences modify vulnerability.

Some individuals cannot sustain euglycemia under this challenge.

Gestational diabetes then becomes clinically apparent.

Slide 12 · Predisposition is multifactorial

Robbins explicitly names concurrent genetic and environmental factors.

No single susceptibility gene is claimed for ordinary gestational diabetes.

The pregnancy-associated insulin-resistance state can unmask existing risk.

The exact combination of factors may differ between individuals.

Slide 13 · Glucose homeostasis has three interacting components

Hepatic glucose production

Peripheral glucose utilization

Insulin–counterregulatory balance

The liver provides glucose particularly in fasting states.

Skeletal muscle is a major tissue for glucose utilization.

Insulin and counterregulatory hormones coordinate both processes.

Slide 14 · Liver: A major determinant of fasting glycemia

Insulin signaling

Suppression of gluconeogenesis

Controlled fasting glucose

Insulin normally restrains endogenous hepatic glucose production.

With insulin resistance, that restraint is diminished.

The parent diabetes section links this defect with increased fasting glucose.

Slide 15 · Muscle: A major determinant after meals

Meal-related glucose

Insulin-dependent muscle uptake

Glucose storage / use

Skeletal muscle increases glucose uptake and glycogen synthesis in response to insulin.

Insulin resistance impairs this postprandial disposal pathway.

The parent section links the defect with increased postprandial glucose.

Slide 16 · Adipose tissue participates in insulin resistance

Reduced insulin response

Less inhibition of lipolysis

More circulating FFAs

Insulin ordinarily suppresses adipocyte triglyceride breakdown.

Insulin resistance can increase circulating free fatty acids (FFAs).

These metabolic changes connect adipose tissue to systemic glucose regulation.

Slide 17 · Three tissues, three important abnormalities

Tissue

Normal insulin action

Effect of resistance

Liver

Suppresses endogenous glucose output

Fasting glucose production inadequately restrained

Skeletal muscle

Promotes glucose uptake and glycogen synthesis

Post-meal glucose clearance impaired

Adipose tissue

Inhibits lipolysis

Circulating FFAs may increase

Slide 18 · β-cell response links glucose load to insulin release

Blood glucose rises

β-cell glucose metabolism

Calcium-triggered insulin release

Glucose is the major physiological stimulus for insulin secretion.

The parent section describes ATP-linked calcium entry and granule exocytosis.

Sustained stimulation also recruits a later phase of insulin secretion.

Slide 19 · Early insulin resistance can be compensated

Resistance increases

β-cell secretion rises

Glucose remains controlled

The general type 2 diabetes pathway initially involves compensatory hyperinsulinemia.

The relevant principle is increased secretory demand when tissues resist insulin.

This is background physiology—not a measured pregnancy-specific trajectory.

Slide 20 · Hyperglycemia emerges when compensation is insufficient

Increasing insulin requirement

Relative secretory inadequacy

Hyperglycemia

Inadequate β-cell function relative to resistance in type 2 diabetes.

The same logic illustrates why insulin resistance need not always cause diabetes.

This diagram is mechanistic context, not a separate gestational diagnostic criterion.

Slide 21 · Resistance is not the same as insulin deficiency

Insulin resistance

Target tissues respond suboptimally to available insulin.

Liver, skeletal muscle, and adipose tissue are key sites.

Secretory compensation may initially mask the defect.

Insulin deficiency

Insulin supply is inadequate for physiological demand.

It may be absolute with β-cell destruction.

Or relative when secretion fails to overcome resistance.

Slide 22 · Insulin signaling offers a cellular explanation

Insulin receptor signaling

Glucose-transporter response

Glucose uptake

The parent diabetes section discusses reduced insulin receptor/IRS signaling.

Reduced cell-surface GLUT4 contributes to impaired uptake in target tissues.

This is a general insulin-resistance mechanism, not uniquely ascribed to pregnancy.

Slide 23 · Type 1 and type 2 mechanisms differ

Type 1 diabetes

Autoimmune injury destroys pancreatic β cells.

Insulin deficiency becomes absolute.

Its mechanism is not defined by insulin resistance alone.

Type 2 diabetes

Insulin resistance is prominent.

β-cell secretion fails to compensate adequately.

Relative insulin deficiency accompanies hyperglycemia.

Slide 24 · Type 1 diabetes: Autoimmune β-cell loss

Loss of immune tolerance

Islet-directed T-cell injury

Progressive β-cell depletion

T cells targeting islet antigens are central to the mechanism.

Progressive cell loss limits endogenous insulin reserves.

If present before conception, this condition is pregestational diabetes.

Slide 25 · Type 2 diabetes: Two coupled defects

Insulin resistance

β-cell dysfunction

Persistent hyperglycemia

Both resistance and insufficient compensatory secretion matter.

Obesity and a proinflammatory metabolic state may contribute.

Type 2 diabetes established before conception is also pregestational diabetes.

Slide 26 · Visceral adiposity is relevant background susceptibility

Central or visceral obesity especially strongly with insulin resistance.

Distribution of adipose tissue matters beyond body mass alone.

This is described in the general type 2 diabetes parent section.

The pregnancy paragraph does not provide a gestational-specific risk ratio.

Slide 27 · Free fatty acids amplify metabolic dysfunction

Enhanced lipid release

Lipid signaling intermediates

Impaired insulin action

The type 2 section implicates increased FFAs in reduced insulin sensitivity.

Intracellular lipid intermediates can attenuate receptor signaling.

This offers general mechanistic context for susceptibility—not a direct GDM biomarker.

Slide 28 · Adipokines alter systemic insulin sensitivity

Adipose endocrine activity

Adipokine signaling

Change in insulin sensitivity

Adipose tissue releases proteins with metabolic effects.

Adiponectin can increase sensitivity; Levels are lower with obesity.

This under type 2 diabetes rather than specifically gestation.

Slide 29 · Inflammation interacts with type 2 metabolic disease

Nutrient excess

Inflammatory mediator release

Resistance and β-cell stress

The type 2 diabetes section describes a proinflammatory milieu.

It contributes to both insulin resistance and β-cell dysfunction.

Distinguish this from autoimmune β-cell destruction in type 1 diabetes.

Slide 30 · Integrating pregnancy with general diabetes biology

Gestational insulin resistance

Individual predisposition / β-cell reserve

Gestational dysglycemia

Pregnancy introduces an insulin-resistant physiological challenge.

The background capacity to maintain glucose control modifies the response.

A conceptual mechanism joins source statements; It is not an obstetric prediction tool.

Slide 31 · Pregestational and gestational disease: Comparison

Dimension

Pregestational

Gestational

Starting glycemic status

Already diabetic

Previously euglycemic

Time of onset

Before conception

During pregnancy

Pregnancy physiology

Can add resistance to established disease

Contributes to first-onset intolerance

Typical after delivery

Preexisting condition remains conceptually distinct

Usually resolves, but later diabetes risk persists

Slide 32 · Type 1 diabetes can predate conception

Before pregnancy

Autoimmune β-cell loss

At conception

Preexisting diabetes

During pregnancy

Gestational insulin resistance

Underlying type 1 pathogenesis precedes the pregnancy in this setting.

An additional insulin-resistant hormonal state occurs during gestation.

This combined exposure belongs to the pregestational category.

Slide 33 · Type 2 diabetes can predate conception

Before pregnancy

Resistance + β-cell dysfunction

At conception

Established type 2 diabetes

During pregnancy

Additional metabolic challenge

Type 2 diabetes is not defined by first appearance during pregnancy.

The underlying defects remain resistance and insufficient secretion.

Clinical chronology—not just mechanism—classifies the pregnancy.

Slide 34 · Gestational diabetes first develops during gestation

Before pregnancy

Euglycemia

During pregnancy

Impaired tolerance / diabetes

After delivery

Usually resolves

The core definition involves dysglycemia newly arising during pregnancy.

Pregnancy-associated insulin resistance is part of the explanatory context.

Typical resolution does not mean risk disappears.

Slide 35 · Maternal hyperglycemia creates several risk pathways

Maternal dysglycemia

Pregnancy / fetal exposure

Adverse outcomes

Pregestational diabetes with stillbirth and congenital malformations.

Later poor control is associated with excessive fetal growth.

Offspring may have increased obesity and diabetes risk later in life.

Slide 36 · Pregestational diabetes: Increased stillbirth risk

Diabetes present before conception is associated with a greater risk of stillbirth.

The passage describes increased risk—not inevitability for an individual pregnancy.

It does not provide an absolute event rate or identify a single causal mechanism.

Clinical management thresholds are outside the supplied paragraph.

Slide 37 · Pregestational diabetes: Congenital malformation risk

Established maternal diabetes with increased fetal congenital malformations.

This association belongs specifically to its pregestational discussion.

A malformation is a structural developmental abnormality, not synonymous with macrosomia.

The excerpt supplies no organ-specific spectrum or risk ratio.

Slide 38 · Stillbirth and malformation are different endpoints

Stillbirth

A fetal death outcome.

Listed among increased risks with preexisting diabetes.

Not itself a structural malformation.

Congenital malformation

Abnormal development of fetal structure.

Also linked to maternal pregestational diabetes.

Cannot be reduced to increased birth weight.

Slide 39 · Pregnancy timing changes the question asked

Diabetes already present

Gestational exposure continues

Later glycemic control matters

Preexisting diabetes means the condition is present at pregnancy onset.

The source also highlights outcomes of later poorly controlled diabetes.

Ask separately about chronology and whether hyperglycemia remains controlled.

Slide 40 · Later poorly controlled diabetes: Fetal macrosomia

Poor glycemic control arising later in pregnancy is linked with excessive newborn weight.

The term macrosomia for this excessive birth weight.

The association applies regardless of diabetes history before pregnancy.

No birth-weight threshold is specified in the supplied passage.

Slide 41 · Macrosomia risk is not confined to gestational diabetes

Pregestational or new-onset diabetes

Poor late-pregnancy control

Excessive newborn weight

The qualifying factor in the text is poor control later in pregnancy.

The same outcome can arise in either chronological diabetes category.

Do not incorrectly reserve macrosomia for gestational diabetes alone.

Slide 42 · Avoid collapsing all fetal complications into one

Associated context

Outcome

What source does not assert

Preexisting diabetes

Stillbirth

That every affected pregnancy ends in fetal death

Preexisting diabetes

Congenital malformation

A specific pattern or quantified fetal risk

Later poor glycemic control

Macrosomia

Restriction to gestational diabetes alone

Maternal hyperglycemia

Later obesity / diabetes in child

Certainty of disease in every offspring

Slide 43 · Maternal and offspring outcomes need separate timelines

Pregnant patient

Diabetes may be preexisting or gestational.

Gestational dysglycemia commonly resolves after birth.

Substantial later risk of overt diabetes remains.

Fetus / offspring

Stillbirth and malformation risks are linked with preexisting diabetes.

Poor late control may cause macrosomia.

Later obesity and diabetes risk may be increased.

Slide 44 · The offspring may face later obesity risk

Obesity later in life among possible offspring sequelae.

This is a long-term association following diabetes-complicated pregnancy.

The paragraph provides neither a causal pathway nor a quantified probability.

A risk association should not be presented as a diagnosis in the newborn.

Slide 45 · The offspring may face later diabetes risk

Increased later diabetes risk is discussed separately from neonatal macrosomia.

The outcome may emerge long after the index pregnancy.

The excerpt does not distinguish specific childhood or adult diabetes phenotypes.

Do not infer a screening test or follow-up interval absent from this source.

Slide 46 · Offspring outcomes span different time horizons

During pregnancy

Stillbirth / malformation associations

At birth

Macrosomia may be present

Later life

Obesity / diabetes risk

These endpoints differ in nature, timing, and interpretation.

The textbook does not assign a uniform risk level across endpoints.

Outcome categories should be described without equating association with certainty.

Slide 47 · Birth removes the pregnancy-related metabolic milieu

Delivery

Gestational influence wanes

GDM typically resolves

Resolution after delivery is the usual course reported by Robbins.

This is a characteristic of the gestational form, not an exclusion of future disease.

The exact physiological timeline of resolution is not provided.

Slide 48 · Postpartum resolution does not mean permanent cure

Short-term course

Gestational diabetes typically resolves after delivery.

The hyperglycemic state may no longer be apparent.

This describes the observed pregnancy-related episode.

Long-term course

Most affected individuals later develop overt diabetes.

The source places this on a 10–20-year horizon.

Underlying susceptibility can remain relevant.

Slide 49 · Long-term risk follows gestational diabetes

10–20 years

Overt diabetes developing in most individuals with prior gestational diabetes over this interval.

A typical postpartum return to euglycemia does not negate future risk.

“Most” is the source’s qualitative statement; No exact proportion is provided.

This is a long-term risk statement, not a prediction for an individual patient.

Slide 50 · Gestational diabetes can reveal a life-course risk

Before conception

Euglycemic

During pregnancy

Gestational diabetes

Immediately postpartum

Usually resolves

Following decades

Elevated overt-diabetes risk

Pregnancy provides a metabolically stressful interval in susceptible individuals.

The episode may precede clinically manifest diabetes later in life.

Temporal resolution and future predisposition are not contradictory.

Slide 51 · Three concepts must be kept distinct

Resolution: Glycemia commonly returns toward normal after delivery.

Predisposition: A vulnerability may exist despite a temporary normal glucose state.

Progression: The source describes subsequent overt diabetes in most affected persons.

None of these labels by itself specifies an individual future diagnosis date.

Slide 52 · Case 1 — diabetes predates the pregnancy

A patient with documented type 1 diabetes becomes pregnant. Gestational insulin resistance is expected to add metabolic demand.

How should this pregnancy be classified?

The defining feature is diabetes present before conception; Its autoimmune mechanism specifies type 1.

Pregestational diabetes.

Slide 53 · Case 2 — new dysglycemia during pregnancy

A previously euglycemic patient develops impaired glucose tolerance during an ongoing pregnancy.

Which chronological form best matches the textbook definition?

Glycemic intolerance appeared for the first time during gestation, in a pregnancy-associated insulin-resistant state.

Gestational diabetes.

Slide 54 · Case 3 — excess birth weight is not type-specific

Poorly controlled hyperglycemia occurs late in pregnancy. The individual had type 2 diabetes before conception.

Is macrosomia excluded because the diabetes is pregestational?

No. Robbins explicitly links poor later control to macrosomia regardless of earlier history.

Macrosomia risk can occur in either diabetes category.

Slide 55 · Case 4 — postpartum euglycemia and future risk

A patient had gestational diabetes. The episode resolves following delivery.

Does the return to euglycemia eliminate the long-term concern?

The source reports overt diabetes developing later in most affected individuals over 10–20 years.

No: Temporary resolution and later diabetes risk coexist.

Slide 56 · Case 5 — separate fetal endpoints

A learner states that congenital malformations and macrosomia are interchangeable consequences of maternal diabetes.

Identify the reasoning error.

A malformation concerns fetal development; Macrosomia describes excessive weight at birth and is tied to later poor control.

They are distinct outcomes and should not be conflated.

Slide 57 · Case 6 — interpreting susceptibility

Two previously euglycemic patients undergo pregnancy-related insulin resistance; Only one develops gestational diabetes.

What explanatory factor is explicitly allowed by Robbins?

The text names concurrent genetic and environmental susceptibility as modifying progression under the hormonal challenge.

Insulin resistance plus individual susceptibility.

Slide 58 · Classification drill: Three independent questions

Question

Reasoning target

Was diabetes present before conception?

Yes → pregestational; no, new intolerance → gestational setting

What is the underlying metabolic defect?

Absolute insulin deficiency, resistance, or inadequate compensation

When did poor control occur?

Exposure timing and degree may change the relevant offspring outcome

Slide 59 · A coherent maternal–fetal model

Pregnancy-related insulin resistance interacts with preexisting diabetes or individual susceptibility.

Maternal setting

Pregestational diabetes or newly gestational dysglycemia

Exposure

Degree and timing of maternal hyperglycemia

Offspring

Malformation / stillbirth associations; Macrosomia; Later obesity or diabetes risk

This is a teaching synthesis of stated associations, not a causal risk calculator.

Slide 60 · Common interpretation errors

Calling all diabetes diagnosed during gestation “pregestational” without prior evidence.

Assuming insulin resistance invariably produces diabetes.

Attributing macrosomia exclusively to gestational diabetes.

Treating postpartum resolution as evidence of zero later diabetes risk.

Converting qualitative risk associations into unsupported numerical forecasts.

Slide 61 · Clinical evidence boundaries in this lecture

The dedicated Robbins passage does not specify gestational screening procedures.

It does not give pregnancy-specific diagnostic thresholds or glycemic targets.

It does not supply drug regimens, delivery algorithms, or quantified endpoint risks.

General nonpregnant diabetes thresholds elsewhere in the chapter must not be substituted for obstetric criteria.

Slide 62 · Core comparison: The complete storyline

Concept

Pregestational diabetes

Gestational diabetes

Origin

Diabetes already established

First development of intolerance in pregnancy

Metabolic context

Pregnancy adds an insulin-resistant state

Pregnancy can expose susceptibility

Pregnancy outcomes

Stillbirth and malformation risks elevated

Late poor control can also cause macrosomia

Long horizon

Underlying preexisting disease

Often resolves, yet later overt diabetes is common

Slide 63 · Essential conclusions

Classify by relationship to conception: Pregestational versus gestational.

Pregnancy-related insulin resistance exposes genetic/environmental susceptibility.

Preexisting diabetes increases stillbirth and congenital malformation risk.

Poor later glycemic control may produce macrosomia irrespective of prior diabetes history.

Gestational diabetes often resolves after delivery but signals substantial future risk.

Slide 64 · Reference and scope

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. 2026.

Primary source section: “Diabetes and Pregnancy” in “The Endocrine System.”

Supporting context: glucose homeostasis, insulin secretion and action, and type 1/type 2 pathogenesis.

No external obstetric guidelines, fabricated statistics, or synthetic diagnostic images were incorporated.