Type 2 diabetes, reproductive health and pregnancy

Contraception advice should follow guidelines that apply to women without diabetes. However, because the risks associated with pregnancy in women with diabetes are high, it is particularly important to consider long-acting reversible contraception as a first-line option to avoid unplanned pregnancy.⁴ The use of the non-hormonal copper intrauterine contraceptive device might be preferred over the combined oral contraceptive pill, depending on any risks or contraindications caused by the presence of diabetes complications.

In all cases, contraception choice should be based on the woman’s preferences, considering the risks and benefits and the presence of diabetes-related complications.

Smoking combined with diabetes and the use of the combined oral contraceptive pill significantly elevates vascular risks.

For more information, refer to the World Health Organization Medical eligibility criteria for contraceptive use.⁵

Information about contraceptive choice is available from the National Diabetes Services Scheme (NDSS) website.

Men

Men with diabetes are three times more likely to develop erectile dysfunction than men without diabetes.⁶ The prevalence of erectile dysfunction in men aged >40 years with diabetes may be as high as 50%, and incidence increases by approximately 10% per year as men age.

Men with diabetes are also affected by erectile dysfunction at an earlier age, with occurrence approximately a decade earlier.^6,7 In addition, diabetes is associated with lower testosterone levels in men.⁸ This might contribute to reduced libido and aggravate or exacerbate erectile dysfunction.

Healthy Male provides a clinical summary guide for the management of male erectile dysfunction.⁹

Women

Sexual dysfunction in women is often under-reported and could co-exist with underlying depression.

Women with diabetes might experience higher rates of sexual dysfunction than women without diabetes: rates of depression, anxiety and psychological distress are higher in people with diabetes and may contribute to sexual dysfunction in women and men.^10,11 It is also fair to say that sexual dysfunction in women could be linked to complications of diabetes, namely vascular and neuropathic complications; however, more research is needed to assess this.^12,13

Symptoms of sexual dysfunction in women include:

• decreased or total lack of interest in intimacy or sexual relations
• decreased or no sensation in the genital area
• a degree of anorgasmia
• dryness in the vaginal area, leading to dyspareunia.

Genital infections such as monilial vaginitis occur more frequently in women with diabetes and may contribute to sexual dysfunction. People taking sodium–glucose cotransporter 2 inhibitors (SGLT2i) are at higher risk of genital infections.¹⁴

More information about evaluating and managing female sexual dysfunction can be found in a paper by Krakowsky and Grober.¹⁵

It is important to enquire about sexual problems in the annual review and manage physical and emotional aspects. A sexual desire questionnaire or screening tool (eg the Decreased Sexual Desire Screener¹⁶) will help with diagnosis and treatment.

For information about gestational diabetes, refer to ‘Gestational diabetes ’.

Pregnancy with pre-existing diabetes

Clinical context

The Australasian Diabetes in Pregnancy Society recommends a fasting and premeal self-monitoring of blood glucose (SMBG) target of 4.0–5.3 mmol/L and a post-meal SMBG target of 5.5–7.8 mmol/L (one hour after the meal) or 5.0–6.7 mmol/L (two hours after the meal), provided that these levels can be achieved without causing significant hypoglycaemia. In early pregnancy, the HbA1c target for women with pre-existing diabetes is ≤6.5% (48 mmol/mol), which is the same as the preconception target. HbA1c is slightly lower in pregnancy compared with outside pregnancy due to increased red blood cell turnover. Therefore, as the pregnancy progresses, a lower HbA1c of ≤6.0% (42 mmol/mol) can be targeted if this can be achieved without causing significant hypoglycaemia.³ Suboptimal glycaemic management at conception and early in pregnancy is associated with an increased risk of congenital malformations and first trimester miscarriages.

Women with pre-existing diabetes (types 1 and 2) are more prone to the complications of pregnancy, such as higher rates of stillbirth,¹⁷ pre-eclampsia prematurity and caesarean section.¹⁸ In addition, pregnancy may accelerate maternal complications of diabetes, such as diabetic retinopathy (see ‘Complications: Diabetes-related eye disease ’).¹⁹ Both maternal and fetal complications are increased by diabetes. Risk is progressive with increasing glycaemia.²⁰

Optimising glycaemic management can mitigate these risks, the likelihood of birth trauma and the risk of early induction of labour and need for caesarean section. Women should be advised that metformin crosses the placenta and that the long-term effects of in utero exposure to metformin on the offspring as they grow to adulthood is unclear, although some recent studies suggest that metformin has benefits to both the mother and offspring.^21,22 There is a small proportion of babies born small for gestation age. This is primarily in women who have hypertension with or without nephropathy. A 24-month follow-up study published in 2023 showed that anthropometrics were similar in children exposed and not exposed to metformin in utero.²³ Cessation or continuation of metformin should be discussed and depends on the risks and benefits of continuation.²³

Women of reproductive age with existing diagnoses of diabetes should be advised of the benefits of contraception to prevent inadvertent pregnancy before glycaemia can be optimised. Women should be advised of the need for advice, education and support to achieve optimal glycaemic management before pregnancy.

Women with type 2 diabetes and polycystic ovary syndrome or irregular periods must be advised that improved fertility may accompany weight loss and the use of therapies, including metformin.²⁴

In practice

Pre-pregnancy

Where possible and practicable, formal, diabetes-specific pregnancy planning should occur prior to pregnancy.

This should be patient-focused, support self-management and involve a multidisciplinary team. Planning should include assessment of diabetes-related complications, review of all medications and commencement of folic acid.^24,25

Deferring pregnancy should be recommended until glycaemic management is optimal. Women should be reassured that any reduction in HbA1c towards the individualised target is likely to reduce the risk of congenital malformations.

Refer to the NDSS for advice on pre-pregnancy blood glucose targets.

Medications should be reviewed and ceased or replaced as appropriate, ideally before pregnancy during the planning period, or urgently once pregnancy is confirmed. Consultation with local specialist services is advised. Agents such as sulfonylureas, glitazones, SGLT2i and incretin-based therapies will need to be reviewed or ceased, and insulin therapy instituted.

Table 1 presents safety profiles and advice for diabetes medications in pregnancy.

Antenatal care

Insulin therapy will need regular review and titration to achieve glycaemic goals.

Insulin requirements are typically increased early in the first trimester.³⁰ Insulin requirements increase further progressively from around 16 weeks gestation to around 36 weeks gestation before declining slightly towards term.³¹ Thus, there is a significant danger of major hypoglycaemia during the first few weeks in the first trimester. Early referral to a multidisciplinary team before 10 weeks is ideal, with an awareness that hypoglycaemia may occur before the woman gets to see the multidisciplinary team. Pregnant women on insulin therapy are recommended to check their glucose levels more frequently during this critical period and reduce their insulin dose appropriately.

Other factors contribute to hypoglycaemia during this early pregnancy period: nausea and vomiting of pregnancy, elevated pregnancy hormonal levels.³⁰ Risk factors include a prior history of severe hypoglycaemia, long duration of diabetes, lower baseline HbA1c and higher total daily insulin dose.³²

Intensive glycaemic management guided by SMBG or continuous glucose monitoring, versus SMBG alone, in studies³³ that included people with type 2 diabetes in pregnancy have failed to demonstrate this benefit compared with type 1 diabetes.³⁴

Close surveillance for new diabetes complications and monitoring of existing complications should occur routinely.

General practitioners (GPs) should provide timely and appropriate support and referral for women who are experiencing an unplanned pregnancy where the risks of abnormal pregnancy outcomes are elevated.

Ultrasound screening is advised at 10–13 weeks gestation (with biochemistry) for trisomies, and at 18–20 weeks for congenital cardiac and other malformations. Pregnant women with diabetes should be offered ultrasound monitoring of fetal growth and amniotic fluid volume every four weeks from 28 to 36 weeks.²⁷ Fetal growth and wellbeing monitoring should occur under specialist supervision. It is strongly recommended to refer to your local specialist endocrine and obstetric services.

During pregnancy

Patients should be referred to specialised diabetes antenatal care as early as possible, because multidisciplinary shared care is considered best practice.^17,27 A multidisciplinary team ideally involves:

• GP
• endocrinologist
• midwife
• obstetrician
• credentialled diabetes educator
• accredited practising dietitian
• psychologist.

Postpartum

The GP should maintain or re-establish contact with the mother and child as early as practicable to address any issues arising from the pregnancy, labour, surgery or breastfeeding, and to review medications.

Metformin may be continued while breastfeeding with minimal effect on the baby.³⁵ Breastfeeding may alter glucose levels, so glycaemic monitoring, oral medications and insulin need careful review during breastfeeding to minimise the risk of hypoglycaemia.

Reintroduction of other medications needs careful review. The LactMed® database contains information on drugs and other chemicals to which breastfeeding mothers may be exposed. Ultimately, studies are lacking with many drugs to give more accurate guidance on risk, and a general rule is to use the pregnancy risk category. The use of insulin may need to be supported until weaning occurs.

Re-establishing glycaemic management goals, reassessment of complications and timely contraceptive advice are also appropriate in the postpartum period.

The Australian Government Department of Health has produced a practice summary for managing diabetes in pregnancy in its Clinical practice guidelines: Pregnancy care. The relevant extract has been reproduced in Appendix 4. 

Australasian Diabetes in Pregnancy Society 2020 guideline for pre-existing diabetes and pregnancy.³ 

The NDSS has produced a pregnancy planning checklist. 

The NDSS and Diabetes Australia have produced a guide to planning and managing pregnancy for women with type 2 diabetes. 

Diabetes UK has developed a guide to pregnancy for women with diabetes. 

The National Aboriginal Community Controlled Health Organisation and The Royal Australian College of General Practitioners National guide to preventive healthcare for Aboriginal and Torres Strait Islander people has information on pregnancy care for Aboriginal and Torres Strait Islander people with diabetes in Chapter 5.