How does diabetes affect fertility and pregnancy?
Scientific support: PD Dr. Sandra Hummel,Prof. Dr. Michael Hummel
In most cases, women with type 1 or type 2 diabetes can get pregnant without any problems. There are certain risks for mother and child. However, these risks can be significantly reduced with good planning.
Women with diabetes who plan to have children should try to ensure their blood sugar levels are optimally managed before getting pregnant. An HbA1c value below 7 percent is recommended or – if the risk of hypoglycemia is low – even below 6.5 percent.
During pregnancy, average blood glucose levels between 90 and 110 mg/dl (5.0 mmol/l to 6.1 mmol/l) should be reached. A diabetologist should always be consulted for planning and care during pregnancy.
Contents
- Does diabetes affect fertility?
- What should you do before pregnancy if you have diabetes?
- What should be considered during a pregnancy with diabetes?
- What important examinations should the patient attend?
- What are the risks for mother and child?
- What is childbirth like for women with diabetes?
- What happens after giving birth?
1. Does diabetes affect fertility?
Normally, type 1 or type 2 diabetes has no negative effect on female fertility. If a woman with diabetes does experience difficulty getting pregnant, this often stems from other diseases, such as polycystic ovary syndrome (PCOS). This hormonal disorder disrupts the menstrual cycle and can lead to infertility.
When PCOS is accompanied by type 2 diabetes and obesity, weight loss can have a positive effect. The metabolism and menstrual cycle often normalize when the patient achieves a normal weight.
Infertility in men may be caused by undetected type 2 diabetes (prediabetes). Although still undetected, the blood sugar levels are already elevated. Nerves and blood vessels can be damaged in this phase, which can affect potency. This can be counteracted with a healthy lifestyle, i.e., a balanced diet and sufficient physical activity.
2. What should you do before pregnancy if you have diabetes?
When planning to get pregnant, women with type 1 or type 2 diabetes should contact their diabetes team. The risk of fetal malformation rises if blood sugar levels are not optimally managed. For this reason, patients with diabetes should undergo specific testing of the following factors before getting pregnant:
- Long-term blood sugar value (HbA1c value)
- Blood pressure
- Blood lipid levels
- Thyroid values to rule out hyperthyroidism or hypothyroidism
In cases of unwanted pregnancy, women with diabetes should seek medical advice as soon as possible.
HbA1c value
The long-term blood sugar level should be below 7 percent (53 mmol/mol) three months before conception. If there is no increased risk of low blood sugar levels, an even lower value of less than 6.5 percent (47.5 mmol/mol) is recommended.
Concomitant diseases and preventive medical examinations
Women with diabetes should also be examined for signs of already existing concomitant diseases before getting pregnant.
For example, the kidneys or the retina of the eyes (diabetic retinopathy) can be affected. Attention should also be paid to high blood pressure. All of this can worsen during
pregnancy and must therefore be monitored regularly. Ophthalmologic checks should be carried out before and during pregnancy and up to 12 months after delivery. Women with diabetes and high blood pressure should be treated with medication that is compatible with pregnancy as soon as they wish to have children.
Food supplements
As with all women who wish to get pregnant, specialist associations recommend beginning with folic acid tablets before pregnancy. Beginning at least 4 weeks before pregnancy and continuing until the end of the 12th week of pregnancy, women should take at least 0.4 milligrams of folic acid (folate) per day.
Smoking
Stopping smoking is essential for a good pregnancy and fetal health.
Nutrition and physical activity
The treatment plan should also include recommendations for diet and physical activity.
We recommend about 40–50 percent carbohydrates (fiber approx. 30 g/day), 30–35 percent mainly vegetable fat and 20 percent protein, as well as sufficient minerals and vitamins (iron, folic acid, vitamin D, calcium, vitamin B, magnesium, iodine).
Physical activity should be compatible with pregnancy, i.e., contact sports or martial arts, or sports with a high risk of falling or injury should be avoided. For example, brisk walking, cycling or swimming are suitable.
Therapy adjustments before pregnancy: type 1 diabetes
Diabetes therapy may need to be adjusted before pregnancy begins. It is therefore recommended to discuss with your diabetologist whether it is advisable to switch to a different insulin preparation or a different therapy technique.
As for all pregnant women, it is also important for women with diabetes to adapt their diet to the special calorie and nutrient requirements during pregnancy.
Therapy adjustments before pregnancy: type 2 diabetes
As with all types of medication, care should be taken during pregnancy. For many types of blood sugar reducing medications, there is little data available on their safety for the unborn child.
For women with type 2 diabetes, medical professionals usually advise switching to insulin therapy. Use is made of intensified insulin therapy or an insulin pump. This means that blood sugar levels can usually be adjusted and fine-tuned very well. Especially during pregnancy and around the time of birth, insulin therapy must be constantly adapted to the changing requirements because changes in sugar metabolism are sometimes considerable. What is more, insulin therapy has few side effects.
The dosage of insulin is not always easy. In addition, the switch to insulin often creates uncertainty. For this reason, women with type 2 diabetes should take part in a course to learn how to inject and measure their blood sugar levels correctly. There they will also learn to use an insulin pen or insulin pump. The costs for the course are usually covered by the health insurance provider.
Good to know:
In some cases, it is possible to get blood sugar levels under control through lifestyle changes, sufficient physical activity and a healthy diet. Many women with type 2 diabetes take the time of pregnancy as an opportunity for more physical activity and a healthier diet – because for the sake of the child, motivation is often particularly high at this time. Another advantage is that such a change in lifestyle not only benefits the child, but also the mother's health. Some women with type 2 diabetes manage to remain free of antidiabetic drugs even after the birth of their child.
3. What should be considered during a pregnancy with diabetes?
Women with type 1 or type 2 diabetes should aim for the following blood sugar levels during pregnancy:
- Before meals: 65–95 mg/dl (3.6–5.3 mmol/l)
- 1 hour after a meal: less than 140 mg/dl (less than 7.8 mmol/l)
- 2 hours after meal: less than 120 mg/dl (less than 6.7 mmol/l)
- Before sleeping (approx. 10–11 pm): 90–120 mg/dl (5.0–6.7 mmol/l)
- At night (approx. 2–4 am): above 65 mg/dl (above 3.6 mmol/l)
It is recommended that pregnant women measure their blood sugar levels 6 times per day (1 hour before each meal, and 1 hour after). The average value should remain between 90 and 110 mg/dl (5.0 mmol/l and 6.1 mmol/l). In principle, all pregnant women on intensified insulin therapy or insulin pump therapy should be offered continuous glucose monitoring (CGM).
Insulin requirements during pregnancy
Blood sugar levels and therefore insulin requirements change during pregnancy until delivery under the influence of pregnancy hormones. During the 1st trimester, the amount of insulin required falls. During this period, the expectant mother must inject less insulin to prevent low blood sugar levels. The insulin requirements increase rapidly during the 2nd trimester and then dramatically fall again after giving birth.
Because the need for insulin decreases, there is an increased risk of low blood sugar levels in the 1st trimester, especially at night. A sensor that continuously measures tissue glucose (CGM) and gives an alarm if the values are too low or too high can therefore be particularly helpful during pregnancy. If blood sugar levels are measured based on a drop of blood , they can be measured around 11 pm to estimate the risk of low blood sugar levels at night: If the reading is less than 110 mg/dl (less than 6.1 mmol/l), the risk increases.
Pregnant women with diabetes should always inform those close to them and their partner about what to do in the event of severely low blood sugar levels.
Ketoacidosis (acid buildup in the blood caused by lack of insulin) associated with pregnancy diabetes is an emergency situation. Expectant mothers should discuss with their diabetes specialist at what blood sugar level they should measure not only their blood sugar levels, but also their acetone in the urine or blood. Then, appropriate rules of conduct apply.
Good to know:
Compared to the 1st trimester, the need for insulin increases in the 2nd trimester by around 50 percent and in the last trimester by up to 70 to 100. The need for insulin then drops drastically again after giving birth.
Food supplements
In addition to the folic acid tablets, a daily intake of 0.1 to 0.15 mg (100 to 150 μg) of iodine and an iodine-rich diet are recommended during pregnancy. The aim is to supply the unborn child with sufficient iodine and prevent thyroid complications. If you have thyroid disease, you should consult your doctor before taking supplements.
Technical aids during pregnancy
Nowadays, blood glucose monitoring is very often carried out using CGM systems. These are measuring systems for continuous glucose measurement. They measure the sugar level in the subcutaneous fatty tissue and help to improve the controllability of insulin therapy. Individually adjustable alarm functions additionally enable early detection of low and high blood sugar levels.
Women with diabetes usually regulate their blood sugar levels during pregnancy with insulin therapy. This usually involves an insulin pen or an insulin pump. The insulin pump is a small device that is connected to a catheter on the body via a tube. The catheter, which is often located on the stomach, can also be placed there during pregnancy. As there is a lot of space between the abdominal wall and the uterus, the catheter does not interfere here. If a caesarean section is necessary for giving birth, the catheter can, for example, also be placed on the thigh for the duration of the procedure.
The most modern form of insulin therapy for type 1 diabetes is the hybrid closed-loop system (or AID system). This is an insulin pump that is coupled with a continuous glucose monitor (CGM). Several hybrid closed-loop systems are already available in Germany, which are covered by statutory health insurance under certain conditions.
Studies are currently underway on the use of hybrid closed-loop systems during pregnancy. Only a few systems are officially approved for use during pregnancy in Germany. An up-to-date overview of available AID systems and information leaflets can be found on the website of the Diabetes and Technology Working Group. The information leaflets indicate whether a device is approved for use during pregnancy.
4. What important examinations should the patient attend?
To ensure good management of type 1 or type 2 diabetes during pregnancy, the patient should attend the following check-ups, among others:
- The German Maternity Guideline suggest three ultrasound examinations, which can be supplemented by additional examinations: 8th to 12th, 11th to 14th and 28th to 32nd week of pregnancy. From the 24th week of pregnancy, ultrasound examinations take place every 2 to 4 weeks. They should take place more often in the event of anomalies.
- Between the 19th and 22nd week of pregnancy, an anomaly scan of the fetal organs can be carried out.
- The long-term blood sugar value (HbA1c value) should be determined at intervals of between 4 and 6 weeks.
- Ophthalmologic examinations to test for retinal damage (diabetic retinopathy) are recommended before falling pregnancy, in the early stages of pregnancy, and then every 3 months until giving birth as well as up to 12 months after delivery. In the event of preexisting retinopathy or a newly developed condition, the ophthalmologist will schedule appointments based on the individual case.
- After the 20th week of pregnancy, regular blood pressure testing should be carried out, or earlier depending on risk factors or signs of disease. The risk of high blood pressure is increased in patients with long-term diabetes. The protein excretion levels in the urine should also be monitored.
- Thyroid panel testing should take place every 4 to 6 weeks.
Before giving birth, an estimation of the birth weight is recommended.
Employment during pregnancy
The Maternity Protection Act stipulates an employment ban for all pregnant women for several weeks before and after giving birth. During the remaining pregnancy, pregnant women can generally carry out their professional activities without any problems, regardless of any underlying diabetes. However, an individual employment ban during pregnancy can also apply outside the usual period if the activity performed endangers the life or health of the mother or child. During the employment ban, pregnant women receive continued payment of wages in full.
5. What are the risks for mother and child?
What are the risks for the mother?
If the blood sugar levels are too high throughout pregnancy, the child can become too large and too heavy (birth weight exceeding 4500 grams). This can lead to complications during birth or cesarean section.
Diabetes-related complications, e.g., affecting the eyes, kidneys, or nerves, can become more pronounced during pregnancy and must be regularly controlled and treated as early as possible. Check-ups should be carried out closely before, during and up to one year after pregnancy.
Pregnant women with diabetes are more likely to develop infections of the genital and urinary organs, which can lead to premature birth. For this reason, regular testing is recommended.
During the later stages of pregnancy, expectant mothers can develop high blood pressure. In this case, self-testing of blood pressure can be carried out on a daily basis.
Preeclampsia, also known as gestosis or pregnancy poisoning, is especially serious. It is characterized by high blood pressure (hypertension) and increased excretion of protein via the urine (proteinuria). Preeclampsia, the most severe form of gestosis, is a very serious emergency situation that requires immediate hospital treatment. To prevent preeclampsia, the intake of low-dose aspirin (150 mg/day) should be discussed with the attending physician. It is usually taken until the 35th week of pregnancy and will be discontinued thereafter.
Good to know:
Women with type 1 diabetes in particular can develop low blood sugar levels during the 1st trimester, especially at night. Therefore, it may be necessary to temporarily change or adjust their course of treatment. Later in pregnancy, the blood sugar levels become more stable and the risk drops.
What are the dangers to the fetus?
The internal organs of the fetus develop during the 1st trimester of pregnancy. If the blood sugar levels are not optimally regulated before and during pregnancy, this can result in malformation of the heart, nervous system, and lungs in particular. Miscarriage and premature birth are also possible. The risk of premature birth (birth before the end of the 37th week of pregnancy) is on average 5 times higher for expectant mothers with diabetes. These risks can be significantly reduced thanks to targeted counseling, good metabolic management, and blood sugar self-testing.
Other typical adjustment problems observed in the child immediately after birth include a tendency to hypoglycemia, a tendency to newborn jaundice (hyperbilirubinemia) and respiratory disorders.
Good to know:
In addition to taking folic acid until the end of the 12th week of pregnancy and an adequate supply of iodine, a sufficient supply of thyroid hormone is also important for the development of the unborn child. The mother's thyroid hormone levels should therefore be checked regularly. If necessary, the doctor will prescribe a thyroid replacement hormone.
Risk of offspring developing diabetes
Later, around 3 in 100 children born to mothers with type 1 diabetes also develop type 1 diabetes, as the disease is partly genetic. Find out here how high the inheritance risk is if the father, both parents or siblings have type 1 diabetes.
No concrete figures are known on the risk of diabetes in offspring of mothers with type 2 diabetes. The risk of type 2 diabetes in offspring also depends largely on lifestyle factors (diet, physical activity, normal weight or overweight).
6. What is childbirth like for women with diabetes?
Expectant mothers are advised to give birth at a perinatal center (at least level 2). These clinics are specialized in high-risk pregnancies and premature births. They have a pediatric clinic with a neonatal intensive care unit and are equipped to provide comprehensive medical care for mother and child. This enables newborns to quickly receive emergency care on site. For example, glucose can be administered intravenously in cases of newborns with low blood sugar levels.
The blood sugar levels of the mother at the start of childbirth should be between 90 and 126 mg/dl (5.0–7.2 mmol/l). Low blood sugar can lead to reduced contraction activity. The blood sugar levels should be monitored every 1 to 2 hours during childbirth and corrected if needed. Only short-acting insulins are administered during childbirth.
If labor begins so early that a substance to inhibit contractions is required, special attention must be paid to the blood sugar levels during this period. Certain types of medication can have a negative influence on metabolism.
Good to know:
All pregnant women with diabetes should give birth at a perinatal center.
7. What happens after giving birth?
Mother and child require close monitoring after birth. The mother's insulin requirements fall rapidly after giving birth, increasing the risk of low blood sugar levels. It may be necessary to individually adjust the required amount of insulin. The dosage used before pregnancy can be used as a reference value. The blood sugar level should be tested at least every 4 to 6 hours, also at night.
When breastfeeding begins, the required amount of insulin can fall even further and adjustment is needed. Attention should be
paid to ensuring sufficient carbohydrate intake during the day to prevent low blood sugar levels at night or after breastfeeding.
To prevent low blood sugar levels in children of diabetic mothers, the baby's blood sugar level is also monitored in the further course. The 1st blood sugar test takes place between 1 and 2 hours after birth. It is important to be aware of the possible signs of low blood sugar.
Find out more about low blood sugar levels here!
Breastfeeding with Diabetes
The children of mothers with diabetes should be breastfed and vaccinated like other children. The risk of children later developing obesity or type 2 diabetes is reduced by breastfeeding. However, in reality, mothers with diabetes tend to breastfeed more rarely and for a shorter period compared to non-diabetic mothers. Studies have shown that mothers with diabetes have more success breastfeeding when they participate in breastfeeding classes before giving birth.
If possible, the newborn should be breastfed for the first time 30 minutes after birth and then every 2 to 3 hours. This has been proven to stabilize the blood sugar level of the newborn and prevent low blood sugar levels. Breastfeeding can also improve the mother's diabetes management.
Good to know:
Breastfeeding women with type 2 diabetes should not use blood sugar-reducing medication. If the blood sugar levels cannot be sufficiently be brought under control with dietary adjustments, then insulin continues to be used.
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As of: 17.06.2024
