Can a child’s speech defect be linked to insulin use in pregnancy? A patient with gestational diabetes at the antenatal clinic asked if insulin causes speech defect in children. She feels one of her child who cannot speak at age 4years was due to the insulin she used to control her blood sugar in that pregnancy. The other child has no problem with speech because she did not use insulin while pregnant. She strongly believes it and also claimed she read online that insulin use in pregnancy causes speech problem in children.

On further probing, she did not develop gestational diabetes in the pregnancy that resulted in that child with no speech problem. Also, the one with speech difficulty is actually having difficulty hearing. So, can insulin use in pregnancy cause speech problem in children? If insulin is not the culprit, what then could be responsible? Stay with me as you will have your answers right here.


The period of organogenesis also called the embryonic period is from the 3rd to the 8th weeks of pregnancy. This is when all the body’s organs are formed, exposure to agents that disrupt the process will result in birth defect.

The development of the sense of hearing starts in the early 4th week of pregnancy. Babies born with deafness maybe from their genetic makeup or the presence of other maternal medical conditions such as; diabetes or infection with toxoplasmosis, rubella, cytomegalovirus, herpes or syphilis.

Hearing plays a significant role in the acquisition and development of communication skills. A child that cannot speak may not be hearing. Children born with deafness can be helped to restore their sense of hearing. They may require surgery to correct any malformation or for insertion of implant. Some may benefit from the use of hearing amplification devices and audiology rehabilitation. Significant progress has been made in research on hearing loss; in auditory hair cell and nerve regeneration.


Insulin is a hormone produce naturally in the body by specific cells in the organ called the pancreas. The hormone is key to the uptake, utilization and storage of blood sugar in the body. It also plays a role in the production of protein and fat in the body. Intake of carbohydrate meal stimulate the release of insulin. The relative, body cells not sensitive to insulin, or absolute deficiency of this hormone insulin results in diabetes.

The discovering of insulin revolutionises the treatment of diabetes; initially, the insulin used was gotten from pig and cow, later, synthetic human insulin was produce with some limitations. The production of synthetic insulin analogue has overcome the limitation associated with human insulin. Available data from studies do not associate insulin use in pregnancy with any major birth defect or miscarriage. Side effect of insulin includes; allergic reaction, weight gain, hypoglycaemia, hypokalaemia.


Gestational diabetes or GDM is carbohydrate intolerance that is first discovered in pregnancy and resolves within six weeks after delivery. In simple term; it means abnormal blood sugar level that is discovered for the first time in pregnancy in a woman who is not previously diabetic.


The cause of gestational diabetes is not exactly known but there are risk factors associated with it. Although, genetic and environmental factors seem to play a major role. Pregnant women with the following risk factors as outlined below are called potential diabetes. They include;

  • Family history of diabetes
  • Previous history of gestational diabetes
  • Obesity; weight at antenatal booking ≥90kg or a body mass index of ≥30kg/m2
  • Previous delivery with one or more babies weighing ≥4kg
  • Previous history of a child with birth defect
  • Previous or current history of too much baby water
  • Previous history of fetal demise
  • Persistent glucose in urine test
  • Recurrent or persistent vaginal discharge


Gestational diabetes is diagnosed using the screening test called oral glucose tolerance test (OGTT) when it is abnormal. The screening for gestational diabetes depends on the guideline for screening in your country, this differ from country to country. In my facility in Nigeria, only women with the above risk factors are screened while in other countries the recommendation is for all pregnant women to be screened.

Oral glucose tolerance test is a screening test for diabetes done between 24 to 28weeks of pregnancy. For patients who book early in pregnancy with the above risk factors, a blood sugar level is determine after a period of fasting and 2hours after eating. However, some experts advocate for an earlier OGTT which should be repeated at 24 to 28weeks of pregnancy.


 Before the OGTT is done, there are some prerequisite to be met and they include;

  • The patient should fast for at least 8hrs prior to the test
  • She should be on her regular diet with no carbohydrate restriction
  • She should not smoke

On the morning of the test, 75g glucose is mix in 250ml of water to be consumed within 5minutes. A blood sample is drawn to measure the fasting sugar level before starting the test. After drinking the solution, blood samples are drawn at one hour and 2hours.  Urine samples are also taken same time as the blood to check for the presence of sugar in the urine.

If any one of the result is abnormal; either the fasting, one or two hours’ blood sugar result, the patient is confirmed to have gestational diabetes.


The complication of GDM could be to the mother or baby and they result from poor sugar control. Sometimes, these complications would have occurred in the baby before the diagnosis of GDM is made. The complication to the mother includes;

  • Eye complication called retinopathy
  • Kidney failure
  • Risk of developing preeclampsia
  • Difficulty in breathing from too much baby water
  • Risk of forming blood clot in the veins
  • Risk of developing type 2 diabetes later in life
  • placenta previa

The complication to the baby includes;

  • Big baby
  • Restriction of the baby’s growth in the womb
  • Birth defect that can involve any body system; including hearing loss
  • Death of the baby in the womb
  • Nerve injury at birth due to big size of the baby


The treatment of a woman with GDM in based on blood sugar level and the presence or absence of complication of GDM. This can be achieved via lifestyle modification, dietary modification and use of medication. For some patient, subscribing to the dietician feeding plan helps to control the blood sugar. However, insulin is needed when the dietary or oral medication control is not maintaining the desired blood sugar control or when there is a complication.