A Practical Manual of Diabetes in Pregnancy

David McCance, Michael Maresh, David A. Sacks, David McCance, Michael Maresh, David A. Sacks

• Publisher: Wiley-Blackwell
• Year: 2017
• Print ISBN: 9781119043768
• eBook ISBN: 9781119043799
• Edition: 2
• Topic: Medicine
• Subtopic: Endocrinology & Metabolism

A PRACTICAL MANUAL OF DIABETES IN PREGNANCY

The second edition of A Practical Manual of Diabetes in Pregnancy offers a wealth of new evidence, new material, new technologies, and the most current approaches to care. With contributions from a team of international experts, the manual is highly accessible and comprehensive in scope. It covers topics ranging from preconception to postnatal care, details the risks associated with diabetic pregnancy, and the long-term implications for the mother and baby. The text also explores recent controversies and examines thorny political pressures.

The manual's treatment recommendations are based on the latest research to ensure pregnant women with diabetes receive the best possible care. The text takes a multi-disciplinary approach that reflects best practice in the treatment of diabetes in pregnancy. The revised second edition includes:

• New chapters on the very latest topics of interest
• Contributions from an international team of noted experts
• Practical, state-of-the-art text that has been fully revised with the latest in clinical guidance
• Easy-to-read, accessible format in two-color text design
• Illustrative case histories, practice points, and summary boxes, future directions, as well as pitfalls and what to avoid boxes
• Multiple choice questions with answers in each chapter

Comprehensive and practical, the text is ideal for use in clinical settings for reference by all members of the multi-disciplinary team who care for pregnant women with diabetes. The manual is also designed for learning and review purposes by trainees in endocrinology, diabetes, and obstetrics.

Section III
Diabetes Preceding Pregnancy

10
Pre‐Pregnancy Care in Type 1 and Type 2 Diabetes

Rosemary C. Temple¹ and Katharine P. Stanley²

¹ Elsie Bertram Diabetes Centre, Norfolk and Norwich University Hospital NHS Trust, Norwich, UK

² Department of Obstetrics, Norfolk and Norwich University Hospital NHS Trust, Norwich, UK

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PRACTICE POINTS

• Pre‐pregnancy care (PPC) is the additional support needed to prepare a woman with diabetes for pregnancy. A principle goal is to advise and support the woman to achieve optimization of glycemic control before conception.
• PPC in women with type 1 diabetes is associated with improved glycemic control in early pregnancy and a threefold reduction in risk of major congenital malformation in the offspring.
• PPC includes commencement of folic acid 5 mg daily preconception; discontinuation of potentially teratogenic medications, such as statins, ACE inhibitors, and certain hypoglycemic agents; and smoking cessation. Dietary input is important to encourage a healthy weight before pregnancy and to optimize glycemic control.
• Pregnancy outcomes for women with type 2 diabetes are the same or worse as those for women with type 1 diabetes. However, women with type 2 diabetes are less likely to receive formal PPC.
• Preconception counseling, as opposed to PPC, should take place at regular intervals throughout the reproductive years. It includes a discussion with the patient about future plans for pregnancy, contraceptive advice, education about the increased risks associated with unplanned pregnancies and how they may be minimized, and advice on how to access PPC.

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Case History

Mary, a 25‐year‐old, was delighted to find she was expecting a second baby. Her first pregnancy had been complicated by gestational diabetes treated with diet. Despite advice to lose weight, she had become depressed following the pregnancy and gained 9 kg. Two years later, she had been diagnosed with type 2 diabetes. She found it difficult to keep to the recommended diet and required metformin and a sulphonylurea for glycemic control. Recently, she had been started on an ACE inhibitor to control her blood pressure. She was about 8 weeks pregnant. Her family doctor referred her urgently to the diabetes antenatal clinic, where she was shocked to discover she would need insulin treatment during her pregnancy as her HbA1c at booking was 68 mmol/mol (8.4%). She later explained that she had not been counseled at any time previously, either about possible risks to a future pregnancy or that she would need to discontinue her oral hypoglycemics and commence insulin. She commenced twice‐daily insulin injections and discontinued her oral hypoglycemics. Her ACE inhibitor was discontinued, and she was started on labetalol and prescribed folic acid tablets. Her 20‐week anomaly scan showed a ventricular septal defect. After 20 weeks, her diabetes became more difficult to control, requiring four insulin injections daily. An additional blood pressure tablet was commenced at 28 weeks. Development of preeclampsia led to an emergency cesarean section at 35 weeks. The baby was admitted to the neonatal care unit for treatment of hypoglycemia, which led to difficulties establishing breastfeeding. The baby will require cardiac surgery later.

• How effective is PPC care in reducing pregnancy complications in women with pre‐gestational type 1 and type 2 diabetes?
• What are the essential components of PPC for women with type 1 and type 2 diabetes?
• What are the aims of tight glycemic control?
• Why do women not access PPC?
• What is preconception counseling, and what should it include?

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Background

Pre‐pregnancy care (PPC) for women with diabetes was introduced 40 years ago and is associated with improved pregnancy outcomes. However, only one‐third of women access PPC, and pregnancy outcomes remain poor. Worldwide, type 2 diabetes is the most common type of diabetes to complicate pregnancy; women with type 2 diabetes are more likely to enter pregnancy with obesity and take potentially teratogenic medications, and less likely to access PPC than women with type 1 diabetes. All healthcare professionals delivering diabetes care should understand the importance of PPC and be skilled to provide preconception counseling, including contraceptive advice.

History of Pre‐Pregnancy Care

Molsted‐Pedersen first described the high incidence of congenital malformations in women with diabetes in 1964, with 6.4% of infants of their diabetic mothers showing a malformation compared to 2.1% of women without diabetes (1). Hyperglycemia was proposed as a possible mechanism, with both animal and human studies supporting this hypothesis (2,3). However, the concept of PPC for women with diabetes was only developed after Pedersen observed the relationship between glucose control and malformations and described how “the occurrence of hypoglycemic reactions and insulin coma during the first trimester was low in mothers with malformed infants,” indicating a positive relationship between maternal hyperglycemia in early pregnancy and the development of fetal malformations (4).

Is Pre‐Pregnancy Care Effective?

Congenital Malformations

The neural tube closes at 6 weeks of gestation. The fetal heart is formed by 8 weeks of gestation. Hence, for an improvement in glycemic control to influence these events, the improvement must occur prior to pregnancy.

Fuhrmann’s study in 1983 of 420 women with type 1 diabetes showed preconception optimization of maternal blood glucose was associated with a significant reduction in congenital malformations, with a malformation rate of 0.8% in the glycemic group that had established preconception compared to 7.5% in the control group (5). By the early 1980s, pre‐pregnancy clinics were becoming part of routine care in some centers, such as Steel’s in Edinburgh (6). Studies have confirmed the effectiveness of PPC, showing improved glycemia in early pregnancy and a reduction in the risk of malformations (Table 10.1) (5–15). However, these studies have all been prospective or retrospective cohort studies, and only five include data on glycosylated hemoglobin.

Table 10.1 Pre‐pregnancy care and congenital malformations in type 1 diabetes.

Data from references (5–15).

Author	Year	PPC number	PPC % malformation	No PPC number	% Malformation	P value
Fuhrmann (5)	1983	128	0.8	292	7.5	0.01
Steel (6)	1994	196	1.5	117	12.0	<0.005
Goldman (7)	1986	44	0	31	9.7	NS
Mills (8)	1988	347	4.9	279	9.0	0.03
Kitzmiller (9)	1991	84	1.2	110	10.9	0.01
Rosenn (10)	1991	28	0	71	1.4	NS
Cousins (11)	1991	27	0	347	6.6	NS
Drury (12)	1992	100	1.0	244	4.1	NS
Willhoitte (13)	1993	62	1.6	123	6.5	NS
Temple (14)	2006	110	1.8	180	6.1	0.07
Murphy (15)	2010	107	0.9	230	5.7	0.02

Two meta‐analyses of studies of PPC, one including over 2500 pregnancies (16) and one with 12 cohort studies ...

Table of contents

• Cover
• Title Page
• Table of Contents
• Contributors
• Foreword
• Preface
• Section I: Introduction
• Section II: Gestational Diabetes
• Section III: Diabetes Preceding Pregnancy
• Section IV: Delivery and Postnatal Care
• Section V: Implications for the Future
• Index
• End User License Agreement