PGDM-GDM Complications
1.What are the fetal complications of Gestational Diabetes Mellitus?
Macrosomia:
Macrosomia is defined as a birth weight > 90th
percentile for population-specific standards, or a birth weight greater than
4kg. Maternal hyperglycemia increases the amount of glucose transferred to the
placenta. In response, fetal insulin secretion increases, resulting in fetal
abdominal fat distribution and visceral adiposity, particularly in the liver
and heart. Macrosomia raises the risk of birth asphyxia.
Shoulder dystocia and Birth Injuries:
Because of macrosomia, the baby's anterior shoulder is
locked behind the pubic bone and cannot be delivered after the head. Macrosomic
newborns are up to ten times more likely to have Erb's palsy.
Still Birth:
Stillbirth is described as fetal loss that occurs after 24
weeks of gestation. The risk of stillbirth is five times greater in diabetic
pregnancies than in non-diabetic pregnancies. Congenital abnormalities alone
cannot explain such a large proportion, but prenatal hypoxia and acidity may be
contributing factors. Fetal hypoxia occurs when hyperinsulinemia causes an
increase in substrate availability, which exceeds the placental oxygen supply.
Neonatal hypoglycemia
Prolonged use can result in brain damage and impaired
neurodevelopment. Transient hypoglycemia is prevalent, affecting roughly half
of diabetic pregnancies. The macrosomic newborn is at risk of hypoglycemia due
to hyperinsulinemia caused by secondary beta cell hyperplasia, which inhibits
hepatic glucose synthesis. Early feeding minimizes the risk of hypoglycemia,
hence all diabetic mothers should be urged to breastfeed within 30 minutes of
birth.
Hyperbillirubinemia
The causes of hyperbilirubinemia appear to be multifaceted,
including birth trauma, erythrocytosis, hemolysis, and immature hepatic
absorption and conjugation of bilirubin.
Respiratory Distress Syndrome
Rather than being a direct result of hyperglycemia, RDS is
more likely to occur due to an increased proportion of preterm delivery and a
high prevalence of LSCS in diabetic pregnancies. Hesitancy in providing
glucocorticoids due to their effect on glycemic control may also contribute to
an increased risk of respiratory distress syndrome.
Other complications:
Infants born to diabetic mothers may develop neonatal
erythrocytosis, transient hypertrophic cardiomyopathy, hypocalcemia, and
hypomagnesemia.
Long term consequences:
GDM adds an intrauterine environmental risk factor to an
increased genetic risk of developing obesity, diabetes, and/or metabolic
syndrome in childhood. Recent research suggests that GDM may increase the risk
of cardio-metabolic morbidities later in life by affecting DNA methylation of
genes related to energy metabolism, anti-inflammatory processes, insulin
resistance, and β-cell apoptosis. However, the exact mechanism remains unknown.
Hyperglycemia alters the expression of angiogenesis-associated molecules in trophoblasts, as well as pro-inflammatory factors including IL-6 and TNF-α, negatively impacting the intrauterine environment. Not only does maternal glycemia affect offspring obesity, but so does maternal glucose intake.
2. What are the Maternal complications of Gestational Diabetes Mellitus?
In terms of maternal problems, GDM is a substantial risk
factor for the development of persistent diabetes later in life (40% in 10
years), as well as GDM in subsequent pregnancies (35%), which increases with
the mother's age and weight. It also increases the risk of preeclampsia.
Several recent investigations have established a link
between GDM and several long-term problems. Stress urine incontinence and mixed
urinary incontinence, a twofold risk of overactive bladder during the
premenopausal period, and cardiovascular morbidity are the most serious.
Increased risks of obstetric complications: Pregnancy-induced hypertension, caesarean section, bradytocia related to macrosomia, and inducement of labor all have an increased prevalence. Complications such as shoulder dystocia increase the risk of postpartum hemorrhage and grade 3-4 perineal tears.
3.What are the fetal complications of Pre Gestational Diabetes Mellitus?
Apart from fetal
complications seen in neonates born to mother with GDM, new born are at
increased risk of congenital malformations (3%) when delivered by mother with
Pre GDM. This occurs due to fetal exposure of hyperglycemia in early pregnancy
(6-8 weeks).
Most commonly anomalies are
seen cardiovascular system followed by musculoskeletal and central nervous
system. As such there is no specific cardiac
abnormalities for diabetes, conotruncal cardiac anomalies are more common in
new born of diabetic mother. TGA, tricuspid atresia and truncus arteriosus are 15 times more common in infant of
diabetic mother.
Caudal dysgenesis is relatively specific to diabetic pregnancy. Many anomalies are part of VACTRAL syndrome. (Vertebral anomalies, anal atresia, cardiac defect, trachea-esophageal fistula, renal anomalies and limb abnormalities). The absolute risk is congenital anomaly is 3% is when pre-conceptional Hba1c is 6.7% and 10% when HbA1c is 11.3%. Rate of pre term delivery is slightly increase in patients treated with metformin compared to insulin.
4.What are the Maternal complications of Pre Gestational Diabetes Mellitus?
There is increase risk of worsening of diabetic retinopathy,
nephropathy and ketoacidosis. DKA is associated with increased risk of fetal
loss.
Diabetic Ketoacidosis:
Although type 2 DM can also occur, type 1 DM accounts for
the majority of instances. Lower glucose levels are more likely to cause
ketoacidosis. Prolonged vomiting and hunger, infections, inadequate glycemic
management, the use of corticosteroids for lung maturation, and other factors
can all cause it. Fetal discomfort is brought on by DKA, and the fetal
mortality rate can reach 10–30%.
Maternal Hypoglycemia
Pregnant women with type 1 diabetes are especially
vulnerable to hypoglycemia, particularly asymptomatic nocturnal hypoglycemia,
which raises the risk of severe hypoglycemia and causes hypoglycemia
unawareness. 61% of women with type 1
diabetes and 21% of women with type 2 diabetes reported recurrent hypoglycemia,
according to CEMACH (Confidential Enquiry into Maternal and Childhood Health).
Diabetic Retinopathy
Pregnancy-related diabetic retinopathy often advances based
on two factors: the severity of pre-existing retinopathy and improvements in
glycemic management. The risk is low for women who do not have retinopathy.
Growth factors are found in higher concentrations in the
blood during pregnancy. PGF (Placental Growth Factor), a VEGF family member, is
making the retina more vulnerable.
Retinopathy can occasionally appear de novo, although it
never develops into proliferative diabetic retinopathy. The emergence of cotton
wool patches is a hallmark of deterioration.
Diabetic Nephropathy
Increased renal failure and pre-eclampsia are maternal risks
of diabetic nephropathy; IUGR, pre-maturity, and mortality are fetal sequelae.
GFR often increases by 50% to 100% during pregnancy. When
pregnant, women with diabetic nephropathy may see a modest increase in GFR but
a sharp rise in protein excretion. In the postpartum phase, the condition
typically returns to its pre-pregnancy level, with the exception of stages 3
and 4.
Pre-eclampsia is a serious problem; it can occur in up to
64% of patients with severe proteinuria and is more likely in people with
microalbuminuria.
Pre-eclampsia is characterized in women who already have
renal illness by worsening hypertension, double proteinuria, and rising plasma
creatinine, thrombocytopenia, and transaminase levels.
Early, rigorous treatment lowers the risk of preterm birth and pregnancy-induced hypertension.
5.What are ways to prevent materno-fetal complications apart from Glycemic control?
Breastfeeding has been identified as a significant
intervention with long-term metabolic benefits for both mother and child.
Lactation was linked to low glucose and insulin concentrations, improved
glucose tolerance, and a significant delay in the onset of type 2 diabetes in
women with GDM. In contrast, the offspring showed protection against excessive
fat accumulation, protection against childhood infections, cardiovascular
diseases, and type 2 diabetes.
Materno-fetal problems appear to be less likely when the
mother's weight is controlled.
The decrease of maternal-fetal problems is further aided by
the prenatal treatment of thyroid issues, hypertension, dyslipidemia, and folic
acid supplements.