Preliminary Note
This practice guideline addresses only type 1 and type 2 diabetes already diagnosed
before pregnancy. These are high-risk pregnancies and require joint care by
specialized diabetologists, obstetricians and neonatologists in close cooperation
with midwives, ophthalmologists and other specialists.
Prevalence
In 2017, German maternity hospitals registered pre-conceptionally-diagnosed diabetes
in 0.93% of about 761 481 pregnancies (n=7096). This prevalence
increased by 5.2% compared to 2016. A differentiation into type 1 and type 2
diabetes is not possible from the available data.
The proportion of pregnant women with type 2 diabetes is estimated at about
20%.
Metabolic Targets
A metabolic adjustment close to the norm should be achieved with an
HbA1c<7% (better<6.5%) for at least 3 months before
conceiving. The blood glucose target values (capillary blood measurements using the
patient’s meter) after the beginning of the pregnancy are compiled in [Table 1].
Table 1 Blood glucose target values (capillary measurement as
plasma equivalent) after the start of pregnancy.
|
Time
|
mg/dl
|
mmol/l
|
|
Fasting, preprandial
|
65–95
|
3.6–5.3
|
|
1 h postprandial
|
<140
|
<7.7
|
|
2 h postprandial
|
<120
|
<6.6
|
|
Before bed
|
90–120
|
5.0–6.6
|
|
At night 2:00–4:00
|
>65
|
>3.6
|
|
Medium blood glucose (MBG)
|
90–110
|
5.0–6.1
|
The mean blood glucose (MBG) values of one day, consisting of 6 values (before main
meals and 1–2 h afterwards), of<90 mg/dl
(5.0 mmol/l) indicate too narrow a setting with the risk of fetal
growth retardation, MBG values of>110 mg/dl
(6.1 mmol/l) are considered to be insufficiently well-adjusted. The
postprandial values (after 1 or 2 h) are important for fetal prognosis, after which
the subsequent preprandial insulin doses should be adjusted.
Immediate postprandial correction should be made as of 200 mg/dl
(11.0 mmol/l). The HbA1c value should be determined every
4–6 weeks and should be within the reference range for healthy individuals.
(Different regional reference ranges of the HbA1c methods should be pointed out. In
general, the HbA1c value before conceiving should be no more than
0.5–1% absolute above the upper reference limit of the laboratory
method used).
The quality of blood glucose self-monitoring by the pregnant woman should be checked
regularly with device-specific control solutions.
CONCEPTT Study
The blood glucose targets required by the guidelines are often not achieved in
pregnant women with type 1 diabetes, and the rate of malformations,
complications and LGA children is therefore unfortunately still significantly
increased. Is the Continuous Glucose Monitoring System (CGMS) an option to
improve glucose control and reduce complications? So far, 3 randomized CGMS
studies have provided an answer to this question, but the data are mixed. Two
studies include type 1 diabetes and type 2 diabetes, in some cases only an
intermittent masked CGMS was used and the case numbers were small, so that in
2017, a Cochrane review concluded that the evidence is small and a large RCT is
needed. In 2017, the CONCEPTT study was published in the Lancet (Feig DS,
Donovan LE, Corcoy R et al. Continuous glucose monitoring in pregnant women with
type 1 diabetes (CONCEPTT): a multicentre international randomised controlled
trial. Lancet 2017; 390: 2347–2359), which addresses this issue.
Inclusion criteria were type 1 diabetes for at least 1 year, age between
18–40 years and suboptimal glycemic control. The primary endpoint was
the change in HbA1c in the 34th week of pregnancy, secondary endpoints were the
results of CGM measurements, the neonatal outcome and other endpoints such as
preterm rupture of the membranes. Using CGM, pregnant women with type 1 diabetes
were able to reduce their HbA1c levels 0.2% more than with conventional
blood glucose monitoring and, 34 weeks later, were in the glycemic target range
for longer (time-in-range). These effects were not observed in women planning to
become pregnant. Infants of CGM mothers showed a reduced risk of LGA
(NNT=6), neonatal intensive care admissions for>24h
(NNT=6), neonatal hypoglycemia with intravenous dextrose administration
(NNT=8), and a one day reduced hospital stay. With CGM, pregnant women
at week 34 spent approximately 100 min longer daily in the glucose target range.
However, the authors' recommendation to consider CGMS as the standard
for type 1 diabetes pregnancy seems premature. It would be important to identify
patients who would particularly benefit from CGMS technology. Also, LGA rates in
this study remained unusually high.
Counseling for Fertility
Human genetic counseling
The risk of children developing type 1 diabetes is 0.8% after 5 years
(5.3% after 20 years). If the father also has type 1 diabetes, the
5-year risk is 11%. If a sibling is also affected in addition to the
mother, the rate is 12% after 5 years. The risk in the general
population is about 0.3% until the age of 25.
Abortion and malformation risk
The risk for early abortions is increased and depends on the pre-conceptional
metabolic control. Numerical chromosomal anomalies are not more frequent in
diabetic pregnancies.
The risk of malformations also depends on the quality of the pre-conceptional
metabolic control, it is on average about 4 times higher compared to the general
population, on average 8.8%. This applies equally to type 1 and type 2
diabetes. In planned pregnancies, the risk of malformations is lower than in
unplanned pregnancies due to targeted counseling, better metabolic control and
blood glucose self-monitoring. Malformations mainly affect the heart and vessels
near the heart (risk: 4-fold), neural tube defects (risk: 2 to 3-fold) and
multiple malformations. There is no diabetes-specific type of malformation. The
frequently-mentioned caudal regression syndrome is very rare (prevalence in
diabetic pregnancies: 1.3/1000). The risk of malformations is also
associated with obesity, microvascular complications and inadequate
periconceptional folic acid substitution in the pregnant woman.
Risk of perinatal mortality and infant death in the first year of
life
The risk of perinatal mortality in fetuses or neonates without malformations
increases significantly above a periconceptional HbA1c of 6.6%. This
also applies to infant death until the end of the first year of life.
Possibilities of reproductive medicine
Fertility in women with well-adjusted diabetes is hardly reduced compared to
metabolically healthy women. If the desire to have children is not fulfilled,
there are no restrictions on the methods of infertility treatment that can be
considered - after completion of the reproductive medical diagnostics in a
specialized center. Cycle disorders are often normalized by an optimized insulin
therapy.
Folic acid and iodide substitution
Periconceptional substitution with 0.4–0.8 mg folic
acid/day, starting at least 4 weeks pre-conception and until the end of
week 12 (to prevent neural tube malformations and cleft lip and palate - if
possible combined with a folate-rich diet), can be recommended to all pregnant
women who wish to have children. Due to the increased incidence of diabetes,
pregnancy and thyroid diseases and to ensure sufficient iodine supply to the
fetus, medicinal iodine prophylaxis with at least 200 µg iodide
per day, information on iodine-rich foods and the use of iodized table salt are
recommended (TSH screening of pregnant women, see below).
Insulin therapy
Insulin is the only well-studied pharmacotherapy for pregnancies with manifest
diabetes. Pregnant women with type 2 diabetes must therefore be switched from
oral antidiabetics to insulin either pre-conception or immediately after the
diagnosis of pregnancy if a diet without rapidly resorbable carbohydrates is not
sufficient. Intensified conventional insulin therapy (ICT) or, if indicated,
continuous subcutaneous insulin infusion (CSII) by means of an insulin pump are
the insulin strategies of choice and equivalent in terms of outcome.
Postprandial blood glucose levels are of particular importance for fetal growth,
birth weight and thus perinatal risks. The strict, normal setting is limited by
the maternal risk of hypoglycemia. Therefore, individual target agreements must
be made in the case of frequent severe hypoglycemia, special life circumstances
and a problematic social environment.
In the first trimester of pregnancy, the risk of maternal hypoglycemia increases
- adverse effects on embryogenesis are not known, but long-term follow-up
observations of the children regarding their psychomotor development are
lacking. The insulin requirement increases continuously starting in the 2nd
trimester of pregnancy (+50–100% until birth) and can be
extremely high, especially in obese pregnant women with type 2 diabetes, while
the risk of hypoglycemia decreases at the same time. At the time of birth, the
insulin requirement drops relatively quickly. At the beginning of labor, the
basal insulin requirement is reduced by about 50% (e. g. below
CSII). During labor, only short-acting insulin is administered, also
intravenously, depending on local practice. Postpartum, insulin substitution is
individually readjusted within a few days; the pre-conceptional need serves as a
guide.
Choice of insulin preparation
Human insulin is the medication of choice. Pregnant women who are well-adjusted
to the short-acting insulin aspart or lispro insulin analogues can continue to
use them. There is no experience with insulin glulisin and insulin degludec.
Women who are well-adjusted to the long-acting insulin analogue insulin detemir
can also continue to use it. Insulin glargin can continue to be used if targets
are well-set before conceiving.
If the metabolic control is optimal during early pregnancy
(HbA1c<7%, no frequent hypoglycemia), a change of insulin
preparations or therapeutic strategies (e. g. CSII for ICT) must be
weighed against the risk of a possible metabolic deterioration.
Diabetological emergencies
It is imperative that pregnant women avoid severe hypoglycemia with the need for
glucose or glucagon injections. A stable, near-normal setting can result in
hypoglycemic warning signs increasingly being suppressed and eventually
disappearing completely due to insufficient hormonal counter-regulation. The
partner or another relative must be informed about hypoglycemia and instructed
in the use of the emergency glucagon kit. Ketoacidosis in diabetic pregnancy is
a critical emergency situation. Immediate admission to a suitable clinic with
emergency medical supervision is indicated. There, coma therapy should be
started immediately according to the in-house treatment plan and the further
procedure should be carried out in close consultation with diabetologists,
obstetricians and neonatologists.
Complications and Concomitant Diseases
Complications and Concomitant Diseases
Arterial hypertension
A distinction must be made between hypertensive forms with pre-conceptional
therapy and pregnancy-specific hypertensive diseases (gestational hypertension,
pre-eclampsia), which only manifest themselves after the 20th week of pregnancy.
The correct blood pressure measurement during pregnancy should be observed
([Table 2]). While the blood pressure
therapy goal before conceiving and up to the 20th week of pregnancy
is<140/90 mmHg, the threshold for the initial blood
pressure intervention in pregnancy is higher after the 20th week: therapy is
only started as of values of 160/100 mmHg as there is a risk of
fetal growth retardation if therapy is started too early. Clinical symptoms of
pre-eclampsia require therapy at lower blood pressure levels. The primary
management of pregnancy-specific high-pressure therapy after the 20th week is
the responsibility of the obstetrician in close consultation with the
diabetologist. In diabetic nephropathy, individual therapy goals are given
priority, the risk of pre-eclampsia is reduced by tight blood pressure control
of<140/90 mmHg before conceiving and before the 20th
week of pregnancy.
Table 2 Notes on correct blood pressure measurement for
pregnant women.
|
5 min of rest before taking the blood pressure
measurement
|
|
Mercury sphygmomanometers with upper arm measurement are
preferable
|
|
Observe proper cuff width (depends on the manufacturer)
|
|
▪ Standard cuff 12–13 cm
wide and 35 cm long for arm circumference of
24–32 cm
|
|
▪ Cuff 15×30 cm for arm
circumference 33–41 cm (thick arms)
|
|
▪ Cuff 18×36 cm for arm
circumference>41 cm (very thick arms)
|
|
▪ Cuff 10×18 cm for arm
circumference<24 cm (very thin arms)
|
|
Pregnant woman sits or lies with upper body raised at a
45° angle
|
|
Remove all clothing from the arm
|
|
Place cuff at heart level for blood pressure measurement
|
|
At the first measurement, compare right and left sides, use
higher value
|
|
Measure blood pressure accurately to the nearest
2 mmHg
|
|
At the first measurement, perform at least two measurements
at intervals of 1–2 min
|
|
In case of increased values, confirm by a second measurement
after at least 4 h
|
|
Systolic blood pressure→Korotkoff phase I
(=Faint tapping sound)
|
|
Diastolic blood pressure→Korotkoff phase V
(=silence)
|
-
Pregnancy per se (hormonal change)
-
Unfavorable pre-conception initial situation
-
Insufficient pre- conception laser coagulation
-
Arterial hypertension
-
Diabetic nephropathy
-
Smoker
-
High periconceptional HbA1c level
-
Diabetes duration>10 years
-
Anemia
ACE inhibitors, AT1 receptor inhibitors and the direct renin inhibitor aliskiren
are contraindicated throughout pregnancy and must be converted before conceiving
– alpha-methyldopa is the medication of choice. If alpha-methyldopa is
not sufficient as monotherapy, it can be combined with cardio-selective
beta-receptor blockers (e. g. metoprolol) and calcium channel blockers
(e. g. nifedipine “off-label”). Atenolol should not be
used because of the risk of growth retardation. Due to the possibility of
neonatal bradycardia with beta-blocker therapy, the neonatologist should be
informed antenatally. Diuretics should not be restarted during pregnancy;
diuretic therapy that has already been started pre-conceptionally can be
continued; thiazide diuretics can make a normoglycemic adjustment difficult
– a therapy adjustment may be necessary.
Other than magnesium sulfate as the basic therapy, the frequently
intravenously-administered dihydralazine is no longer the drug of first choice
due to its complication rates at higher doses for the treatment of hypertensive
emergencies and impending eclampsia. Nifedipine and urapidil are the preferred
alternatives. A combination of magnesium and nifedipine can cause a greater drop
in blood pressure due to the potentiating effect of both substances.
Diabetic retinopathy
This is the most common microvascular complication in diabetic pregnant women and
can first manifest itself during pregnancy. Existing lesions may worsen during
pregnancy, usually in the 3rd trimester. Risks of progression are:
In the absence of diabetic retinopathy, 4 ophthalmologic examinations with
dilated pupils are indicated:
-
Pre-conception in pregnancy planning
-
Immediately after diagnosis of pregnancy
-
Every 3 months until birth
In case of already diagnosed retinopathy or new manifestation, individual
controls are agreed upon by the ophthalmologist (who must be a retinal
specialist). If an active, proliferative retinopathy exists in the case of
infertility (possibly with insufficient metabolic control), the complete
regression of the retinal findings should be awaited after adequate laser
coagulation and the metabolism should be lowered to the required target range
before planning to conceive.
Diabetic retinopathy is not per se an indication for C-section delivery. If
retinopathy is known, multiple individual controls are indicated in the 1st year
after delivery.
Diabetic nephropathy
Pre-conception stage classification should be based on the new clinical
nephropathy classification (see Nephropathy Practice Guideline). Pregnancy per
se does not lead to a decrease in GFR after birth.
After the diagnosis of pregnancy, an albumin screening should be performed at the
beginning of each trimester, even if the results are negative. The screening for
albuminuria (mean value from 2 spontaneous urine samples due to high
variability) correlates well in pregnant women with albuminuria with the urine
collected over 24 h (spontaneous urine: microalbuminuria
20–200 mg/l,
macroalbuminuria>200 mg/l; 24-h-urine: microalbuminuria
30–300 mg/24 h,
macroalbuminuria>300 mg/24 h) and, at its first
appearance, indicates an increased risk of pre-eclampsia and preterm birth,
among others. Due to the possibility of false negative and false positive
results when measuring albumin in spontaneous urine without urinary creatinine,
simultaneous measurement of this value is recommended (women: microalbuminuria
30–300 mg/g creatinine,
macroalbuminuria:>300 mg/g creatinine). False positive
findings, e. g. during physical exertion, urinary tract infections or
insufficiently-controlled diabetes must be taken into account.
Nephropathy stages 1a/1b are associated with increased rates of
pre-eclampsia and preterm birth. This risk is reduced by adjusting blood
pressure to target values<140/90 mmHg. The rate of
preterm births before the 34th week of gestation can also be reduced by
treatment of normotensive pregnant women with type 1 diabetes and
microalbuminuria with alpha-methyldopa.
Nephropathies in diabetic pregnancy from stage 3 according to KDOQI are rare, but
associated with high fetal, neonatal and infantile risks (preterm birth rate,
growth retardation, intrauterine death, perinatal/neonatal mortality,
psychomotor retardation in childhood). There is also a significant
maternal-social risk after birth: inclusion in the dialysis program, increased
mortality before their children reach adulthood. Pregnancies in diabetic women
during hemodialysis or peritoneal dialysis, as well as after a double kidney or
kidney-pancreas transplant are very rare.
Especially high maternal and fetal risks should be pointed out in case of
diabetic nephropathy and the desire for children with:
-
A serum creatinine level of 1.5 mg/dl
(133 µmol/l and above),
-
Nephropathy from stage 3 (creatinine
clearance<60 ml/min×1.73 m2)
-
Arterial hypertension that is difficult to control
An individual risk assessment in cooperation with the nephrologist is
essential.
Diabetic neuropathy
In the case of planned pregnancy and a diabetes duration>10 years, it
should be checked whether there are indications of diabetic gastroparesis,
orthostatic hypotension or hypoglycemia perception disorders. Pregnancy per se
does not lead to the recurrence or progression of neuropathic changes.
Macroangiopathy
Women with diabetes have a 3-fold increased cardiovascular risk, which is further
increased by pregnancy. At risk are women who are older, with a long diabetes
duration, nephropathy, arterial hypertension and who are smokers. After a
myocardial infarction, women should wait at least one year before becoming
pregnant. An individual risk analysis in cooperation with the cardiologist is
imperative.
Thyroid
There is a high prevalence of autoimmune thyroiditis in diabetic women,
especially those over 30 years of age. Before conceiving or when pregnancy is
diagnosed, TSH should be determined. If the TSH level is elevated, FT4 and TPO
should be determined and a thyroid sonography should be performed. Subclinical
hypothyroidism must be substituted with L-thyroxine. Because of the increased
risk of postpartum thyroid dysfunction, laboratory tests (TSH) should be
performed within 3–12 months after birth. Iodide administration during
and after pregnancy can also be carried out in the case of an increased TPO
titer. Autoimmune thyroiditis of the Hashimoto type is thereby neither induced
nor aggravated.
In cases of manifest hyperthyroidism in pregnancy, low doses of thiamazole or
propylthiouracil can be used as monotherapy.
Thyrostatic drugs are harmless even in low doses during breastfeeding. Iodide is
contraindicated in hyperthyroidism.
Examinations to Diagnose Fetal Condition
Examinations to Diagnose Fetal Condition
Ultrasound examinations
The maternity guidelines provide for 3 ultrasound examinations, which must be
supplemented by additional examinations in diabetic pregnant women:
-
8th–12th week: physical integrity of pregnancy and heart
movement
-
11th–14th week: nuchal translucency measurement (optional)
-
19–22nd week: differentiated organ diagnostics (according to
Level DEGUM II)
-
From 24th week: biometrics every 2–4 weeks, more often in case of
abnormalities
Ultrasound signs for diabetes-specific macrosomia are:
-
Increase in abdominal circumference>75th percentile (according to
Hadlock) with normal growth of head and femur
-
Abdominal circumference considerably larger than the head circumference
in relation to week of gestation
Before delivery, an estimation of the birth weight and assessment of the ratio of
abdomen (insulin-sensitive) to head (non-insulin-sensitive) is recommended.
Doppler ultrasound
The indication for this examination is independent of the diagnosis of diabetes
in pregnant women. It is an additional monitoring method in case of growth
retardation of the fetus [Table 3].
Table 3 Action steps for the desire for children, pregnancy,
birth.
|
Time/event
|
What to do?
|
|
Desire to have children
|
▪ Consultation with diabetologist and
gynecologist
|
|
▪ Analyze accompanying risks
|
|
– Retinopathy (referral to ophthalmologist)
|
|
– Nephropathy (urinary albumin, serum creatinine, GFR
according to MDRD equation)
|
|
– Neuropathy (anamnesis and clinical examination)
|
|
– Coronary heart disease (clinic, ECG, ergometry,
echocardiography)
|
|
▪ 0.4–0.8 mg folic acid/day,
advice on folate-rich food
|
|
▪ Exchange oral antidiabetics for insulin
|
|
▪ Check training status, instruct relatives on
glucagon set
|
|
▪ Check thyroid function with TSH screening
|
|
▪ Prescribe iodide
200 µg/day, recommend iodized salt,
nutritional advice
|
|
▪ Optimize metabolism (HbA1c<7%) for
at least 3 months
|
|
▪ Adjust high pressure therapy (exchange ACE
inhibitors/AT-1 antagonists for
alpha-methyldopa)
|
|
▪ Exchange glargine for NPH insulin
|
|
Pregnancy diagnosis
|
▪ Consultation with diabetologist and
gynecologist
|
|
▪ Information about blood glucose targets
|
|
▪ Ophthalmologisch examination
|
|
▪ Urinary albumin screening, then at the beginning of
each trimester
|
|
Every 4–8 weeks
|
Check blood glucose self-monitoring device with control
solution
|
|
8–12th week
|
Ultrasound - check the progress of the pregnancy
|
|
11–14th week
|
Ultrasound – optionally perform nuchal translucency
measurement
|
|
As of 16th week
|
Adjust insulin dose as the need increases
|
|
19–22th week
|
Differentiated organ diagnostics (DEGUM Stage II - German
Society for Ultrasound in Medicine)
|
|
20–24th week
|
Ophthalmological examination
|
|
As of 24th week
|
Biometrics every 2–4 weeks
|
|
As of 32nd week
|
CTG control, frequency to be decided individually
|
|
32–36th week
|
Contact with perinatal center (at least LEVEL 2)
|
|
34–36th week
|
Ophthalmological examination
|
|
36–38th week
|
Estimate birth weight (>4500 g - discuss
planned C-section)
|
|
Early labor
|
Admission to the inpatient labor clinic, bed rest, tocolysis
PO: nifidepin (off-label), i. v. Atosiban (therapy
of choice)
|
|
Immenent premature birth
|
Fetal lung maturation induction with 2×12 mg
betamethasone over 24 h, adjust insulin dose
(+20–40%)
|
|
Gestational hypertension Pre-eclampsia
|
▪ ASS 100 mg/day for prevention in
high risks, high pressure therapy from
160/100 mmHg, earlier for symptoms
(performed by perinatal center)
|
|
▪ Adequate monitoring
|
|
Birth clinic
|
Timely appointment (at the latest in week 36 of pregnancy),
for insulin therapy at the LEVEL 2 or LEVEL 1 perinatal
center
|
|
Birth
|
Spontaneous delivery is aimed for, no further injections of
long-acting insulin at the start of labor, continue to use
pump (basal rate to 50%)
|
|
Inducing
|
When the calculated delivery date is exceeded
|
|
C-section Child
|
primary and secondary only from obstetrical indication
|
|
Kind
|
▪ Planned and unplanned only from obstetrical
indication
|
|
▪ Examination and evaluation by neonatologists within
24 h of birth, immediately in case of clinical
abnormalities
|
|
▪ Immediate skin-to-skin breastfeeding with 30
min
|
|
▪ First blood glucose measurement after 2 h of life
(see AWMF Guideline 024/006)
|
|
Breastfeeding
|
Recommendation for 6–12 months, support in every
respect
|
|
Documentation
|
Document diabetes basic data and data on
pregnancy/birth/newborn child
|
Cardiotocography (CTG)
The frequency of CTG controls should be adjusted to the individual fetal and
maternal risks. This allows early detection of impending intrauterine asphyxia,
particularly with fetal risks such as growth retardation or macroscopic
tendencies.
Contraction stress test, biophysical profile, hormone determination, amniotic
insulin, fetal movements
The contraction stress test as well as the determination of the biophysical
profile are obsolete as routine measures in diabetes. Measurements of estriol
and placental lactogen are also obsolete. Amniotic fluid insulin measurements
from the 28th week of gestation are suitable for the quantification of fetal
hyperinsulinism, but because of the invasiveness (amniocentesis required) and
the fact that only a few centers offer fast and reliable laboratory tests, they
are not a routine method and are therefore reserved for individual cases.
In some cases (e. g. in rural areas), the self-monitoring of fetal
movements by the pregnant woman by means of daily counts (“count to
ten”) can help to improve the early detection of fetal risks in the home
environment if ultrasound/Doppler ultrasound and CTG are not available
promptly or close by.
Treatment of Obstetric Complications
Treatment of Obstetric Complications
Infections
The frequency of urogenital tract infections in diabetic pregnant women is
increased and associated with an increased rate of preterm births. Therefore,
regular check-ups and early antibiotic therapy are recommended.
Preterm birth
Inhibiting contraction
Preterm contractions are treated with the aim of extending the gestation
period until lung maturity is complete. Tocolysis over a longer period
should be avoided. Oral tocolysis with a beta-mimetic and/or
magnesium sulfate is ineffective. Due to the glycogenolytic effect and the
frequent simultaneously-prescribed bed rest and glucocorticoid
administration, IV tocolysis with a beta-mimetic leads to a considerable
increase in blood glucose levels, so that insulin therapy must be adjusted
at short notice: day 1+25%, day 2 and 3+40%,
day 4+20%, day 5+10–20%. The
additional insulin requirement is calculated on all days from the insulin
requirement prior to steroid administration and includes all
basal/bolus and correction administration (following the example of
the National Hospital in Copenhagen). The oxytocin antagonist Atosiban is
metabolically neutral and is considered to be the first choice as IV
tocolytic.
Inducing lung maturity
The risk of preterm birth (birth before 37th week of gestation) is almost 5
times higher on average for diabetic mothers. At the same time, fetal
hyperinsulinism inhibits surfactant formation resulting in the risk of
respiratory distress syndrome in the newborn. In cases of imminent preterm
birth before the 34th week of gestation, inducing fetal pulmonary maturation
with 2×12 mg betamethasone every 24 h is indicated. After
the start of glucocorticoid administration, an increase in the insulin
requirement by 20–40% must be expected for 4 days.
Maternal complications and emergencies - hypertension,
pre-eclampsia/eclampsia
Pre-eclampsia is defined as an increase in blood pressure
> 140 mmHg systolic or>90 mmHg
diastolic in combination with protein
excretion>300 mg/24 h after 20th week of
gestation. In gestational hypertension, proteinuria is absent. In severe
pre-eclampsia, blood pressure values of>160 mmHg systolic
and/or>110 mmHg diastolic are measured. In the case
of such findings, the aim of intervention is to prevent eclampsia, which is
characterized by the occurrence of cerebral seizures and the risk of
intracerebral bleeding. The main symptom of HELLP syndrome, a typical
complication of pre-eclampsia, is persistent right-sided upper abdominal
pain in combination with specific changes in laboratory values:
thrombocytopenia, hemolysis and increased transaminases. As part of primary
prevention, by taking 100 mg acetylsalicylic acid (ASA)/day,
starting no later than the 16th week of pregnancy, the risk of pre-eclampsia
can be reduced in cases classified as high risk by obstetricians. In
particular, these include pregnant women with type 1 diabetes with arterial
hypertension and nephropathy. ASA should be discontinued before birth at
approx. week 37 in accordance with the obstetrician instructions specific to
the individual case. General primary prevention with low-dose ASA in all
pregnant women with type 1 and type 2 diabetes can be advocated and is
decided by the obstetrician. After the 20th week, high pressure therapy
should be started as of 160 mmHg systolic or 100 mmHg
diastolic. This can also be initiated earlier and with proper monitoring
depending on clinical symptoms. The individual risk of pre-eclampsia can be
assessed by Doppler ultrasound of the uterine artery
(“Notch”).
Giving Birth
Choice of maternity clinic
For all pregnant women with type 1 or type 2 diabetes (with insulin therapy),
giving birth must be planned in a perinatal center of at least level 2
(guideline of the Joint Federal Committee of Physicians and Health Insurance
Companies - Gemeinsamen Bundesausschusses der Ärzte und Krankenkassen).
Early presentation at the clinic is mandatory, by week 36 at the latest. In the
case of malformations diagnosed before birth, delivery must take place at a
clinic with a direct connection to the corresponding surgical specialty area
(pediatric, neurosurgery, cardiac surgery).
Inducing birth and indication for C-section
The indications for inducing labor correspond to those of metabolically healthy
women. When the calculated date of delivery is reached, active birth management
is indicated, exceeding the due date should be avoided. Early inducing as a
routine method increases the C-section rate without reducing neonatal risks. The
mother's diabetes is not per se an indication for a planned C-section.
If the estimated weight>4500 g (for small women:
4250 g), a planned C-section should be considered due to the increased
risk of shoulder dystocia. For an estimated weight of
4000–4499 g: inform the pregnant women individually about the
increased specific risk of shoulder dystocia according to fetal biometrics,
especially in the case of a pronounced head-abdomen difference. The indication
for an unplanned C-section should be encouraged in the event of obstructed labor
or an abnormal CTG.
Metabolic control during labor
Blood glucose targets during labor should be 80–130 mg/dl
(4.4–7.2 mmol/l). Maternal hypo- or hyperglycemia as
well as severe fluctuations in blood glucose should be avoided using a treatment
plan with instructions for infusions and insulin dose adjustment. This plan must
be present in the delivery room and must have been authorized by
interdisciplinary, authorized internal staff and remains in effect until the
umbilical cord has been cut. At the beginning of labor, only short-acting
insulin should be injected instead of long-acting insulin for better therapy
control. The insulin pump can be used until the end of the labor with a lowered
basal rate, even in the case of birth by C-section (attachment e. g. to
the upper arm). During labor, hourly blood glucose checks are indicated for the
pregnant woman (point-of-care test), from which immediate therapeutic
consequences must be drawn. After the placenta is delivered, the insulin dose
must be adjusted.
Perinatal morbidity and mortality
The preterm birth rate is 5 times higher (absolute: 25–58%),
depending on metabolic control. The transfer rate to the neonatal intensive care
unit is also increased. The 7 infantile complications include hypoglycemia,
hyperbilirubinemia, polycythemia, transient hypertrophic cardiomyopathy,
respiratory disorders and convulsions.
The total perinatal mortality after the 22nd week up to day 7 of life
is not different for type 1 and type 2 diabetes (2.8% and 2.5%).
However, the rates are 4 to 6 times higher than in the general population.
Etiological factors play a role:
Postpartum and Postnatal Aspects
Postpartum and Postnatal Aspects
In the first few hours after birth, no or very little insulin may be required.
Approximately 3 days after birth, the insulin requirement is reduced by about
20% compared to before conceiving and the risk of hypoglycemia is increased.
Blood glucose should be monitored every 4–6 h during this period to promptly
detect trends in blood glucose development.
Breastfeeding and vaccination of children of diabetic mothers
Breastfeeding is strongly recommended for all mothers with diabetes. During
breastfeeding, the insulin requirement may be reduced. Regular vaccinations of
children do not increase their risk of type 1 diabetes. Children of mothers with
type 1 diabetes are not at increased risk for beta-cell autoimmunity after
supplementation with cow's milk formula compared to hydrolyzed infant
formula.
Special Features of Type 2 Diabetes
Special Features of Type 2 Diabetes
Pregnancies in type 2 diabetes are on the rise. The perinatal risks are at least as
high as for type 1 diabetes. Compared to type 1 diabetes, pregnant women with type
2
diabetes have a higher rate of obesity, a higher age, a shorter diabetes duration
and a higher rate of concomitant risks and medication. They are more likely to
belong to an ethnic minority. In addition, chronic arterial hypertension is more
frequent, while pre-eclampsia is less frequent. Preparation before conceiving is
worse and they take folic acid less frequently before conceiving. The first medical
appointment is usually only after completion of embryogenesis, and a high percentage
are treated with oral antidiabetics during early pregnancy. Before conceiving, a
high percentage of pregnant women with type 2 diabetes do not receive diabetic care,
and in about 30% of cases, no HbA1c was documented 6 months prior to
conceiving. The percentage of unplanned pregnancies is higher than for type 1
diabetes.
Type 2 diabetes in pregnant women should not be trivialized as the risks are
comparable to type 1 diabetes. Training before conceiving, conversion from oral
antidiabetics to insulin as well as diabetological co-supervision are necessary. The
metabolic targets are similar to those of type 1 diabetes.
Quality Control
Pregnancies in which diabetes was already diagnosed beforehand are a rare event in
a
high-risk situation. The treatment quality of both outpatient and inpatient care for
this target group should be centralized in the hands of specialized teams
(competence centers). It should be obligatory to record pregnancies in which
diabetes was already diagnosed in terms of process and outcome quality and to
compare these with formulated health objectives. Structured questionnaires should
be
made available for this purpose by the German Diabetes Society (Deutsche Diabetes
Gesellschaft) and the German Society for Gynecology and Obstetrics (Deutsche
Gesellschaft für Gynäkologie und Geburtshilfe).
German Diabetes Association: Clinical Practice Guidelines
This is a translation of the DDG clinical practice guideline
published in Diabetologie 2020; 15 (Suppl 1): S1-S8,
DOI 10.1055/a-1193-3815
