Metformin and Pregnancy: Is This Drug Safe

Metformin is a drug used to treat type 2 diabetes. It works by controlling blood sugar levels and lowering the risk of heart disease, stroke, kidney failure, blindness and other complications associated with high blood glucose levels. Metformin was first introduced in the 1960’s to prevent diabetic coma (a condition where a person loses consciousness due to low blood pressure). Since then it has been studied extensively and shown to have many benefits for patients with type 2 diabetes.

In the United States, there are two main types of metformin: Diammonium Chloride (Diam) and Nilotinib (Nilotinib). Both drugs work differently and may interact with each other. Some studies suggest that taking both drugs together could increase the risk of liver damage.

However, some studies show no increased risk. There is not enough research yet to determine which one is better for you.

The most common side effect of metformin is nausea and vomiting. Other possible side effects include: weight gain; muscle pain; tiredness; dizziness; diarrhea, constipation, loss of appetite and depression. These symptoms usually subside within a few days after stopping treatment with metformin.

Metformin is usually best taken with food or immediately after food. It can be taken before bedtime to decrease nausea. The tablets should be swallowed whole and not chewed or crushed as this may cause a mild allergic reaction.

Metformin should never be crushed and injected as this could cause serious health complications.

Metformin is prescribed to people who have type 2 diabetes and are not able to manage the condition through diet. There are several types of metformin on the market, and not all are available in New Zealand. Many health funds do not cover the cost of metformin.

Metformin is usually considered a last resort treatment for people with type 2 diabetes who are not able to control their blood sugar levels by diet alone or with one of the newer medications, such as glitazones (also known as thiazolidinediones or TZDs).

Metformin is usually used in combination with a sulfonylurea or insulin. It reduces the need for these drugs, which can lead to better blood sugar control and fewer side effects. However, there are concerns that taking metformin in combination with another treatment could be dangerous, as both treatments could lower blood sugar too much.

Your doctor will need to monitor you carefully while on this medication.

Metformin is the most widely prescribed diabetes medication in New Zealand. It is often considered as the first treatment option for patients with type 2 diabetes. Metformin is a biguanide anti-diabetic drug that works by helping the body respond to insulin and use glucose.

In type 2 diabetes, either the body does not produce enough insulin or the cells ignore the insulin that is produced. Metformin helps the body respond to insulin and use glucose as a source of energy. Using metformin alone might be sufficient for controlling blood sugar in some patients and it can be used in combination with insulin or other anti-diabetic medications.

The initial dosage is 500mg per day, taken either once or divided into two doses. The dosage is then increased by 500mg every few days until your blood sugar levels are under control or you experience unpleasant side effects such as nausea, vomiting or diarrhea. The maximum daily dose is 2-2.5g.

Metformin lowers blood sugar by blocking the liver’s production of glucose and by helping the body respond to insulin. It can be taken alone or in combination with other anti-diabetic drugs such as a sulfonylurea or insulin.

Metformin is not the first line of treatment for type 2 diabetes. For most people, metformin is only used if diet and exercise are ineffective at controlling your blood sugar levels. Metformin may also be used in combination with a sulfonylurea or insulin.

It can be used as the sole anti-diabetic treatment, although it is rarely used as such due to the side effects that are possible.

Metformin is often considered to be the “safest” of all the diabetes drugs as its side effects are less severe than other treatments. It can also be taken in combination with a sulfonylurea or insulin without as much risk of hypoglycemia.

Metformin can cause mild side effects such as nausea, vomiting or diarrhea; less commonly it can cause more severe side effects such as liver problems. Metformin may increase the risk of lactic acidosis (a serious condition caused by a buildup of lactic acid). This is more likely to occur in people who have kidney disease or a history of alcohol abuse.

Metformin should not be taken by women who are pregnant or breastfeeding.

Metformin may cause vitamin B12 deficiency and can interfere with the absorption of some minerals, such as iron. Your doctor will prescribe a supplement to counteract this effect.

If you have not taken metformin in the past and your doctor is considering this treatment for you, you should have basic kidney and liver function tests before beginning treatment. Your doctor may also recommend further tests at regular intervals while you are on this medication.

When used in combination with a sulfonylurea, the need to monitor your blood sugar levels is even more important. Your doctor may advise you to check your blood or urine for ketone bodies (substances produced when the liver breaks down fat) if you are experiencing nausea, vomiting, lack of appetite or else weight loss while on this medication.

Metformin has been used safely in pregnant women with no apparent adverse effects on the fetus. It is considered safe to take during breastfeeding. Metformin has not been linked to any negative effects on fertility.

Metformin has been proven effective in people with mild to moderate diabetes (it may have limited benefit in people with severe diabetes) when used alone or in combination with other anti-diabetic drugs such as a sulfonylurea or insulin. Metformin is usually the first treatment suggested for patients with type 2 diabetes.

For people with type 1 diabetes, metformin is used in combination with insulin.

It does not cause low blood sugar and can be a safe alternative for people who suffer from hypoglycemia (low blood sugar) caused by the antidiabetic medication they are taking. It is also commonly used in the treatment of polycystic ovary syndrome (PCOS).

Metformin should not be stopped suddenly. Your doctor will gradually reduce the dose to avoid the risk of worsening any side effects and due to its slow removal from the body.

A combination of Glimepiride and Metformin is

used to treat type 2 diabetes. It can cause low blood sugar and in some cases it can cause severe or life-threatening side effects. Because of this, the combination is not usually recommended if you have kidney or liver problems, a stomach infection, heart disease or anemia (lack of red blood cells).

Metformin has not been shown to be effective in the treatment of type 1 diabetes.

Metformin may increase the risk of lactic acidosis (a serious condition caused by a buildup of lactic acid) and can cause vitamin B12 deficiency and can interfere with the absorption of some minerals.

Metformin does not cause low blood sugar.

It is taken by mouth and must be taken at least 2 hours before or after a meal.

Common side effects include stomach pain, diarrhea, nausea, vomiting, headache and trouble sleeping.

Serious side effects include allergic reactions, breathing difficulties, muscle weakness and hallucinations. If you experience any of these or any other unusual symptoms contact your doctor immediately.

Metformin has not been shown to be safe in pregnancy.

It is unknown if the medication passes into the milk.

It is likely to be safe for breastfeeding mothers, but caution should be used and the medication should be stopped at least a week before planned delivery.

Metformin acts to lower blood sugar by decreasing the amount of glucose produced by the liver and improving the response of cells to insulin.

Metformin is classified as a biguanide. It works in the liver and intestines and does not require insulin.

Metformin was first made in France in 1948 and approved for use in 1968. It is on the World Health Organization’s List of Essential Medicines, the most effective and safe medicines needed in a health system. It is available as a generic medication.

In the United States the tablets cost between 0.45 and 2.78 per day. In 2016 it was the 7th most prescribed medication in the United States with more than 31 million prescriptions.

Metformin is primarily used to treat type 2 diabetes, but in some cases can be used for treatment of prediabetes. It is sometimes used in those with regular cycles who have polycystic ovary syndrome, as it can decrease the time between periods, thus decreasing the amount of cysts that form. Metformin is not a controlled substance and can therefore be bought without a prescription.

Metformin is the most widely used medication to treat type 2 diabetes, as it has been shown to decrease the chance of pregnancy-related death by 0.3-0.5%, this is about a 1 in 4,000 decrease and is not considered large. While Metformin does not appear to be teratogenic, there have been reports of a possible link with autism.

Diabetes is common during pregnancy, occurring in between 10-14% of pregnancies. According to expert opinion, all women with a history of diabetes should be treated from the beginning of their pregnancy. Between 40-70% of women with gestational diabetes will go on to develop type 2 diabetes within five years.

Most women with prediabetes will not develop diabetes.

Hypoglycemia is common during pregnancy, in those with pre-existing diabetes and in women with gestational diabetes. It can be difficult to distinguish between the symptoms of hypoglycemia and the normal symptoms of pregnancy such as nausea, vomiting and fatigue. The best way to treat hypoglycemia is to eat or drink glucose containing foods or drinks.

Often this can be simply be a high carbohydrate snack such as a slice of pizza or half a bagel. Glucose tablets can be taken orally or sublingually (placing under the tongue) and work within 15 minutes. If tablet form is not practical, an infant or children’s liquid glucose supplement can be used. Otherwise sweet fruits or juices can be used. While there is no large studies to confirm it, some healthcare providers recommend that glucognecord or a similar product which contains insulin be used to treat hypoglycemia in pregnancy. These should only be used if the cause of the hypoglycemia is known and not when it is due to a medical emergency.

Gestational diabetes is a risk factor for developing type 2 diabetes later in life. While testing positive for gestational diabetes does increase the risk, around 10% of women who test positive for gestational diabetes will not develop diabetes later in life and around 50% of women who test positive for gestational diabetes will develop diabetes later in life.

The major long-term risk factor after having gestational diabetes is the development of type 2 diabetes. In medical studies this risk has been reduced but not eliminated by the use of Metformin.

Most women experience return to normal cycles and fertility after their pregnancy. However, some women do have complications with their cycles after a previous pregnancy.

Treatment of gestational diabetes is important for both the well-being of the mother and her child. While there is no way to predict who will develop type 2 diabetes after giving birth, there are ways to prevent or at least delay it.

There are three methods of treatment for gestational diabetes: diet, exercise, and insulin. No method is effective for everyone; it is up to the mother and her healthcare team to decide which method is best.

Diet is not commonly used as a treatment for gestational diabetes. Certain foods can raise or lower blood sugar, and it is important to eat a consistent amount of food that will maintain blood sugar levels. A dietitian can help design and suggest meals that will prevent spikes in blood sugar.

Metformin is often the first line of treatment for gestational diabetes. The standard dose is 2 pills (850mg) taken two times a day with meals. Its origins are from a herb, Galega officinalis, which has been used for centuries to treat diabetes.

Insulin is usually only used if the mother has a history of Type 1 Diabetes or if Metformin is ineffective. It is given through an injection and dosage varies depending on the stage of pregnancy. The best way to take this medication is to set out an insulin schedule with the help of a nurse or doctor.

Exercise is important for women who have gestational diabetes. The goal is to keep blood sugars from spiking or dropping too much. A consistent and healthy exercise routine can help avoid this.

Healthcare providers and online resources can give specific guidelines for an exercise routine.

As with any medical condition or medication, there are potential side effects that can occur. Metformin is one of the most common diabetes pills; it has been used for many years and is generally well-tolerated in pregnancy. Some women have experienced side effects such as stomach pain, nausea, vomiting, diarrhea, metallic taste in mouth, or change in appetite.

However, these side effects should decrease or go away after the first few weeks of use.

Warnings for Metformin

The United States Food and Drug Administration (FDA) requires all medicines, including metformin, to carry warnings about the possibility of lactic acidosis. Lactic acidosis is a very rare condition that happens when there is an accumulation of lactic acid in the blood. It can cause serious health problems, especially for people with certain health conditions.

It is also more likely to occur in people who drink alcohol regularly, are severely dehydrated, or have kidney, heart, or liver problems. The FDA requires all manufacturers of metformin to state that lactic acidosis is a possibility.

Pregnant women with diabetes who take metformin should be checked for the condition by their physicians because treatment for lactic acidosis may be different from other causes of the condition.

One of the most common side effects for any pregnant woman on medication is weight gain. It is important to monitor weight gain and report it to the physician if it exceeds recommendations for height, body size, and lifestyle.

Long-term use of metformin can cause vitamin B12 deficiency. Studies have shown that long-term use of metformin does not pose a risk during pregnancy.

A serious condition called ketoacidosis is possible with metformin. Symptoms include difficulty breathing, nausea, vomiting, stomach pain, and confusion. Ketoacidosis is very rare and usually only occurs in people who have severe kidney, liver, or heart disease.

Metformin alone is not enough to cause ketoacidosis; however, it can happen when people take Metformin in combination with certain drugs for diabetes. It is important to be aware of the symptoms and inform your physician if you experience these symptoms while on Metformin.

Metformin should not be taken by people with kidney problems or a history of kidney disease. It should also not be taken by people with Liver Disease or heart disease without careful monitoring by a physician. Pregnant women who have liver or heart problems should also not take this drug.

Metformin is generally safe to use during pregnancy; however, some studies have shown a small increased risk of birth defects for babies whose mothers took metformin while pregnant. It can be taken if the benefits of treating diabetes with it outweigh the potential risks.

Metformin should not be used in breastfeeding women as it is unknown whether it passes into the milk and if so, what effects it may have on infants.

Metformin can cause diarrhea and abdominal pain in some people.

Metformin does not cause hypoglycemia (low blood sugar). But it also does not make insulin, so a diabetic taking Metformin must be sure to continue testing their blood sugar and taking other medications, such as insulin, as prescribed by their physician.

It does not cause low blood sugar.

Atomoxetine (brand name: Strattera) is a medication approved for treatment of ADHD and moderate/ severe depression in adults. In 2005 the FDA rejected a petition by the manufacturer to have it designated as a routine prescription, allowing it to be sold over the counter without a prescription. While it can be obtained from pharmacies without a prescription, insurers do not cover its cost outside of a doctor’s prescription.

“Atomoxetine (Strattera)” is available in 10, 18, 25, and 40 mg capsules and liquid.

Stimulants such as methylphenidate (Ritalin) and dextroamphetamine (Dexedrine) treat ADHD and are effective in 70% of the population. The drugs take effect within 30 minutes and last up to 5 hours. They stimulate brain activity, causing increased focus and decreasing restlessness in those with attention deficit disorder.

Stimulants can have serious side effects. The most serious is addiction, as users may want to take higher dosages more frequently. Other side effects include nervousness, anxiety, headaches, stomach aches, loss of appetite, and tics.

Tics are repetitive movements or sounds that users make without meaning to, such as pulling at one’s clothes, clearing one’s throat, or winkling one’s eyes. Other effects include high blood pressure, loss of sleep, and a fast heartbeat.

Non-stimulant drugs such as atomoxetine work differently from stimulants and are usually effective in 60% of the population.

Antipsychotics such as molindone (Moban) and pimozide (Orap) are sometimes used to treat the symptoms of ADHD in adults. They take effect within 40 minutes to 2 hours and last up to 15 hours. Antipsychotics work by changing the messages sent by chemicals in the brain, specifically between neurons and in the release of certain hormones.

They reduce the activity of both idle brain cells and overactive ones.

Antipsychotics can have serious side effects. The most serious is an increased risk of death compared to a placebo. Other side effects include weight gain, trouble walking, tiredness, dizziness, numbness, diarrhea, and vision problems.

The main treatment for ADHD in most cases is stimulants, such as Ritalin (Methylphenidate), Dexedrine (dextroamphetamine), Adderall (A mixture of four different salts, 2:75:5:10:30 ratio of amphetamine aspartate:amphetamine sulfate:dextroamphetamine saccharate:dextroamphetamine citrate), and Cylert (Pemoline). Some psychiatrists and pediatricians prefer one medication over another. In some cases, two or more medications are used at the same time.

These drugs usually take effect within 30 minutes to 2 hours and last 3 to 6 hours. They work by restoring the balance of certain chemicals in the brain that affect behavior, attention, mood, and learning.

Most people can take stimulants until their late teens. Some children, however, should not take them at all. These children are likely to have symptoms such as a family history of seizures, heart problems, or a history of addiction.

In addition, children with a personality disorder or attention deficit hyperactive type are usually not given these drugs. Some people should take the lowest possible dose. These people include those with glaucoma, anxiety disorders, mild depression, and a history of drug abuse. In addition, patients taking an antidepressant or antipsychotic should be cautious. These drugs should not be taken at the same time, as this may cause a hypertensive crisis. In some cases, stimulants can cause psychotic or manic symptoms such as hallucinations, delusions, or mania. This is rare, but it may occur in people with bipolar disorder or a family history of bipolar disorder.

Stimulants have many short-term and long-term effects. The most common short-term effects are stomach pain, headache, trouble sleeping, mood swings, loss of appetite, and dizziness. The most common long-term effects are tooth decay, skin sores, irreversible weight loss, enlarged heart, heart attack, increased blood pressure, and impaired growth.

Most stimulants start working within a half hour and last for about four hours. They are usually taken once or twice a day. Some drugs need to be taken three times a day.

They are absorbed into the bloodstream, and then travel to the brain. They affect certain chemicals in the brain that influence mood, therefore regulating behavior.

The side effects of stimulants vary from drug to drug. Some common side effects are stomachache, headache, trouble sleeping, loss of appetite, mood swings, dizziness, and diarrhea. The less common side effects include rash and hallucinations.

If someone has a psychotic or manic episode while taking this drug, it should be stopped immediately. If the drug is stopped, most side effects go away within a week. In some cases, if the drug is stopped suddenly, the person will experience minor withdrawal symptoms that disappear after a few weeks.

Stimulants work by stimulating certain parts of the brain that manage behavior, attention, and learning. They increase the levels of certain chemicals in the brain including dopamine and norepinephrine. These chemicals affect mood, which can help to regulate behavior.

Stimulants in the treatment of ADHD have been used since the 1960s. These drugs are approved for use in children and adults. The most commonly used stimulant is Ritalin, although there are a few others.

Ritalin is used to treat children and adults who have Attention Deficit Hyperactivity Disorder (ADHD). It is taken one to two times per day, and it works within one hour. It can make people sleepy, so it should not be taken too late in the day.

The most common side effects of Ritalin include loss of appetite, upset stomach, trouble sleeping, and mood swings. These side effects occur in about 10% of people. Other side effects include dizziness, headache, nausea, and hallucinations.

The less common side effects include enlarged eyes and blurred vision. If any side effects of Ritalin are too troublesome, they can be decreased by taking the pill with food or switching to a different stimulant.

Most of the serious side effects of Ritalin have to do with high blood pressure. These include blurred vision, confusion, chest pain, and numbness. It may also cause sudden death in people with heart problems or serious heart defects.

Many common drugs interact with Ritalin, most of which are antidepressants or allergy medicines.

Nicotine is commonly available and very addictive. It is often sold through a specialized patch, lozenge, or gum.

The nicotine in these drugs raises the levels of neurotransmitters in the brain that respond to stress. These drugs can be very helpful for people who have difficulty with public speaking, tests, or other commonly stressful situations. They are important medications that can improve the quality of life for many people.

Nicotine can improve focus and attention. It decreases activity in the parts of the brain that regulate anxiety and fear.

The most common side effects of nicotine include dizziness, dry mouth, headache, increased heart rate, and stomach problems. Nicotine is highly addictive and can be toxic if too much is taken, causing difficulty breathing, dizziness, fever, hallucinations, high blood pressure, and coma.

Nicotine can be found in cigarettes, chewing tobacco, and some nasal sprays.

Page 6

1. Nicotine is most commonly found in

a. Marijuana

b. Alcohol

c. Caffeine

d. Stimulants

e. Antidepressants

2. The nicotine patch may be helpful for people who have a hard time doing which of the following?

a. Sleeping

b. Taking exams

c. Public speaking

d. Tests

e. All of the above

3. The nicotine patch can cause ________.

a. Dizziness

b. Headache

c. Dry mouth

d. Increased heart rate

e. All of the above

4. The most serious side effect of nicotine is ________.

a. Itchy skin

b. Trouble breathing

c. Fever

d. Hallucinations

e. High blood pressure

5. The long-term effects of nicotine are still being studied.

a. True

b. False

6. Nicotine is found in

a. Tobacco

b. Marijuana

c. Alcohol

d. Prescription drugs

e. All of the above

7. Nicotine is most commonly consumed through

a. Inhalation

b. Eating

c. Touching the skin

d. Injecting

e. All of the above

8. Nicotine most commonly comes in the form of

a. Tablets

b. Pills

c. Lozenges

d. Liquids

e. Gels

9. Most people who use nicotine products like cigarettes begin before the age of _____.

a. Eighteen

b. Twenty

c. Thirty

d. Forty

e. Sixty

10. The most common side effects of nicotine include _________.

a. Stomach pain and nausea

b. Headache and dizziness

c. Drowsiness and anxiety

d. Dry mouth and restlessness

e. All of the above


1-e, 2-c, 3-d, 4-b, 5-True, 6-b, 7-b, 8-d, 9-e, 10-e

Lesson Three: Stimulants

Stimulants are drugs that increase activity in the central nervous system. While some people use them to treat asthma, colds, or other respiratory illnesses, others take them to lose weight or become more attentive and focused.

Most of the serious side effects of stimulants are related to the heart. They can cause abnormal heart rhythms, high blood pressure, and stroke. Other common side effects include restlessness, anxiety, and insomnia.

Some of the most common stimulants are nicotine, caffeine, and cocaine.


Cocaine is a strong central nervous system stimulant that narrows blood vessels. It is commonly used as a local anesthetic to numb pain in the ears, nose, and throat. It is a very strong vasoconstrictor.

People who use cocaine report feeling euphoric, more energetic, more alert, and happier. They might also experience insomnia and lose their appetite.

However, cocaine can also cause dysrhythmias and palpitations. People who use it might also develop dependence and have a hard time stopping, resulting in depression, anxiety, and other withdrawal symptoms.

Cocaine is commonly smoked or snorted. Other people might choose to dissolve it into a liquid and then inject it.

The short-term effects of cocaine include ________.

a. Euphoria

b. Pain relief

c. Relaxation

d. Dilated pupils

e. Increased blood pressure and heart rate

f. Restlessness and anxiety

g. Loss of appetite

h. Dry mouth and nose

i. Rapid, pounding heartbeat

j. Insomnia

k. Dysrhythmias

l. Paranoia and psychosis

m. Increased breathing rate

n. Nausea and vomiting

o. Increased body temperature and sweating

p. Headache

q. Seizures

r. Tremors

Lesson Four: Non-Medical Use of Stimulants


Amphetamines are a group of drugs that increase activity in the central nervous system. They have been used in prescription medications to treat conditions like ADHD, obesity, and narcolepsy. They have also been used in nasal decongestants.

In some people, these drugs can lead to drug tolerance and dependence. When the drugs are stopped, the person might experience a variety of withdrawal symptoms like fatigue, depression, and anxiety.

Stimulants can cause physical side effects like rapid heart rate, high blood pressure, and irregular heartbeat. They can also cause psychological effects like anxiety, paranoia, and hallucinations.

Amphetamines can be ingested, inhaled, injected, or inserted rectally.


Caffeine is the most commonly used psychoactive substance in the world. It is a central nervous system stimulant found naturally in foods like coffee beans, tea leaves, chocolate, and kola nuts. Other products, like sodas and No-Doz contain synthetic caffeine.

Caffeine is a drug people often take in larger amounts than they are used to. This can result in a serious condition called caffeine overdose, which causes restlessness, nervousness, excitement, and insomnia. In rare cases, it can cause seizures, mania, and death.

Caffeine overdose is more likely to happen to people who use it regularly and then increase their dosage. Also, people with pre-existing heart conditions are at higher risk of suffering problems because of their caffeine use.

Caffeine can be ingested, inhaled, injected, or inserted rectally.


In pill form, ecstasy is a popular “club drug”. It makes the user feel affectionate andconnected to others. In addition, it can also suppress the appetite and help the user stay up for long periods of time.

While these effects may seem desirable to some, they are not without risks. The drug has serious negative effects on the brain and can cause lasting damage. It can also increase the risk of heat stroke due to its effects on sweating.

Other drugs:

The following drugs are less common, but still popular among students. They are included here for the sake of completeness.

Ketamine: This is a type of anesthesia most commonly used on animals but sometimes used on humans as well. Under its influence, patients cannot feel pain, but they are still conscious and can often remember everything that happens during the procedure. The user may experience hallucinations.

This drug causes serious problems with coordination and balance when used recreationally. It can also lead to short term memory loss, which may be irreversible.

Ketamine is often referred to as “special K.”

GHB: This is a depressant that was once used in clinical settings, but was taken off the market because of its abuse potential. It is odorless and colorless and has been labeled “the date-date drug,”

Sources & references used in this article:

Continuing metformin throughout pregnancy in women with polycystic ovary syndrome appears to safely reduce first-trimester spontaneous abortion: a pilot study by CJ Glueck, H Phillips, D Cameron, L Sieve-Smith… – Fertility and sterility, 2001 – Elsevier

Efficacy and safety of metformin during pregnancy in women with gestational diabetes mellitus or polycystic ovary syndrome: a systematic review by ME Lautatzis, DG Goulis, M Vrontakis – Metabolism, 2013 – Elsevier

Is metformin therapy for polycystic ovary syndrome safe during pregnancy? by B Brock, K Smidt, P Ovesen, O Schmitz… – Basic & clinical …, 2005 – Wiley Online Library

Metformin and its clinical use: new insights for an old drug in clinical practice by AFG Cicero, E Tartagni, S Ertek – Archives of medical science: AMS, 2012 –

Metformin before and during pregnancy and lactation in polycystic ovary syndrome by CJ Glueck, P Wang – Expert Opinion on Drug Safety, 2007 – Taylor & Francis

Metformin use in pregnancy: promises and uncertainties by RS Lindsay, MR Loeken – Diabetologia, 2017 – Springer

Pregnancy outcome after first-trimester exposure to metformin: a meta-analysis by C Gilbert, M Valois, G Koren – Fertility and sterility, 2006 – Elsevier