Nutrition in the Childbearing Years

341 Pages·3.235 MB·English

by  Emma Derbyshire(auth.)

Nutrition
in the Childbearing Years
Nutrition
in the Childbearing Years
Emma Derbyshire
BSc,PhD,RNutr
SeniorLecturerandResearcherinHumanNutrition,
ManchesterMetropolitanUniversity
A John Wiley & Sons, Ltd., Publication
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Includesbibliographicalreferencesandindex.
ISBN978-1-4443-3305-3(pbk.:alk.paper) 1.Pregnancy–Nutritionalaspects. I.Title.
[DNLM:1.MaternalNutritionalPhysiologicalPhenomena. WQ175]
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2011007521
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Contents
Foreword xi
Preface xvii
Dedication xviii
Acknowledgements xix
Glossary xx
1 NutritionandFertility 1
1.1 Introduction 1
1.2 Nutritionandfemalefertility 2
1.3 Nutritionandmalefertility 12
1.4 Conclusion 20
2 PreparingtheBodyforPregnancy 25
2.1 Introduction 26
2.2 Nutrientstores 26
2.3 Bodyweightbeforepregnancy 28
2.4 Theimportanceofabalanceddiet 29
2.5 Whatarewomeneating? 29
2.6 Anoteondietaryrecommendations 30
2.7 Compliancewithcurrentrecommendations 31
2.8 Afocusonalcohol 33
2.9 Afocusoncaffeine 33
2.10 Afocusoncalcium 34
2.11 Afocusonfolate 34
2.12 Afocusoniron 36
2.13 Emerginginterestincholine 38
2.14 Multivitaminandmineralsupplements 38
2.15 Applicationinpractice 39
2.16 Foodsafety 39
2.17 VitaminA 41
2.18 Fishconsumption 41
2.19 Peanutallergy 42
2.20 Foodadditivesandingredients 43
2.21 Organicfood 43
2.22 Otherconcerns 43
2.23 Applicationinpractice 44
2.24 Conclusion 44
vi Contents
3 HormonalandPhysiologicalChanges 50
3.1 Introduction 50
3.2 Beforeconception 51
3.3 Afterconception 52
3.4 Formationoftheneuraltube 55
3.5 Foetalgrowth 56
3.6 Keyhormones 57
3.7 Keyphysiologicalchanges 61
3.8 Conclusion 69
4 NutrientMetabolisminPregnancy 74
4.1 Introduction 74
4.2 Energymetabolism 75
4.3 Carbohydratemetabolism 78
4.4 Lipidmetabolism 80
4.5 Proteinmetabolism 83
4.6 Calciummetabolism 84
4.7 VitaminDmetabolism 87
4.8 Ironmetabolism 89
4.9 Folicacidversusfolate 92
4.10 Conclusion 95
5 MacronutrientsandPregnancy 100
5.1 Introduction 100
5.2 Foodcravingsandaversions 101
5.3 Energy 102
5.4 Carbohydrate 104
5.5 Sugar 106
5.6 Protein 107
5.7 Fat 109
5.8 Fibre 111
5.9 Water 113
5.10 Dairyproducts 114
5.11 Salt 116
5.12 Applicationinpractice 116
5.13 Foodchoices 117
5.14 Dietaryassessment 118
5.15 Dietqualityindex 119
5.16 Biomarkers 119
5.17 Applicationinpractice 120
5.18 Conclusion 120
6 VitaminsandPregnancy 126
6.1 Introduction 126
6.2 VitaminA 127
6.3 Thiamine(vitaminB ) 129
1
6.4 Riboflavin(vitaminB ) 130
2
6.5 Niacin(vitaminB ) 130
3
6.6 Pantothenicacid(B ) 130
5
6.7 Pyridoxine(B ) 130
6
6.8 Biotin 131
6.9 Cobalamin(B ) 132
12
6.10 Folate 133
Contents vii
6.11 Choline 137
6.12 VitaminC 138
6.13 VitaminD 140
6.14 VitaminE 141
6.15 VitaminK 142
6.16 Combinedvitamindeficiencies 142
6.17 Supplementsandpregnancy 143
6.18 Applicationinpractice 143
6.19 Conclusion 144
7 MineralsandPregnancy 149
7.1 Introduction 149
7.2 Macrominerals 150
7.3 Microminerals 153
7.4 Applicationinpractice 162
7.5 Conclusion 162
8 DietandPregnancyOutcome 168
8.1 Introduction 168
8.2 Whatisa‘healthy’baby? 169
8.3 AnoteonApgarscores 170
8.4 Whatisfoetalgrowthrestriction? 170
8.5 Poorpregnancyoutcomes 170
8.6 Sensitivewindowsofpregnancy 171
8.7 Alcohol 172
8.8 Caffeine 174
8.9 Dietarymutagens 178
8.10 Pesticides 182
8.11 Hypospadias 182
8.12 Nutrigenomics 183
8.13 Foetaloriginsofadultdisease 185
8.14 Supplements 187
8.15 Applicationinpractice 190
8.16 Conclusion 190
9 WeightGaininPregnancy 195
9.1 Introduction 195
9.2 Bodyweightbeforepregnancy 196
9.3 Weightgain–howmuchandwhen? 198
9.4 Componentsofweightgain 199
9.5 Proportionsofpregnancyweightgain 199
9.6 Measuringbodycompositioninpregnancy 200
9.7 Highpregnancyweightgain 203
9.8 Lowpregnancyweightgain 207
9.9 Weightgainguidelines 209
9.10 Multiplefoetuses 210
9.11 Weightretention 210
9.12 Weightlossinterventions 211
9.13 Whataboutphysicalactivity? 211
9.14 Anoteonweightmanagement 212
9.15 Applicationinpractice 212
9.16 Conclusion 213
viii Contents
10 SpecialCases 218
10.1 Introduction 218
10.2 Pregnantadolescents 219
10.3 Advancedmaternalage 223
10.4 Multifoetalpregnancies 224
10.5 Maternalobesity 227
10.6 Diabeticmothers 228
10.7 Phenylketonuria(PKU)inpregnancy 230
10.8 Vegetarianmothers 231
10.9 Alternativedietarypractices 232
10.10 Nutritionandculture 234
10.11 Conclusion 235
11 PhysiologicalandHormonalChangesafterBirth 241
11.1 Introduction 241
11.2 Whenis‘postpartum’? 242
11.3 Changesafterbirth 242
11.4 Lactogenesis 247
11.5 Anoteoncolostrum 251
11.6 Whatistransitionalmilk? 251
11.7 Nutritionalcompositionofmilk 251
11.8 Milksynthesis–useitorloseit 252
11.9 Milkvolume 253
11.10 Breastfeedingascontraception 254
11.11 Breastcancerrisk 254
11.12 Bodyweightafterbirth 254
11.13 Breastfeedingandbodyweight 255
11.14 Bodycompositionchanges 256
11.15 Exerciseandbreastfeeding 256
11.16 Weightlossinterventions 257
11.17 Conclusion 257
12 NutritionafterBirth 262
12.1 Introduction 262
12.2 Isbreastbest? 263
12.3 What’sinbreastmilk? 264
12.4 Breastfeeding–forhowlong? 264
12.5 Whoisbreastfeeding? 266
12.6 Infantfeedingsurvey 267
12.7 Whydowomenstopbreastfeeding? 267
12.8 Feedingandinfantgrowth 269
12.9 Dietaryrequirementsafterbirth 269
12.10 Vegetarianandveganmothers 276
12.11 Feedingmultiples 276
12.12 Allergyrisk 276
12.13 Postnataldepression 277
12.14 Supplementuseafterbirth 279
12.15 Healthyeatingfromanearlyage 280
12.16 Applicationinpractice 280
12.17 Conclusion 281
Contents ix
APPENDICES
Appendix1 Internationaldefinitionsofindicesusedtoformdietary
recommendations 289
Appendix2 Recommendednutrientintakesforwomenofchildbearing
age(19–50years) 290
Appendix3 Recommendednutrientintakesforpregnancy 292
Appendix4 Recommendednutrientintakesforbreastfeedingmothers 293
Appendix5 Recommendednutrientintakesforpregnantandlactating
adolescents(14–18years) 294
Appendix6 Suggestednutritionalrecommendationsfor
twinpregnancies 295
Appendix7 Tolerableupperintakelevels(ULs)forvitamins
andminerals 296
Appendix8 InstituteofMedicinepregnancyweightgainguidelines 297
Appendix9 Examplesofcommonfoodsafetyconcerns 298
References 301
CASESTUDIES
Planningapregnancy 305
Oldermother 307
Multifetalpregnancy 308
Teenagemother 310
Vegetarianmother 311
Breastfeedingmother 313
Overweightmother 314
Index 315
Foreword
Nutrition during the childbearing years plays a major role in the health of both
mother and child. Poor maternal nutritional status is associated with adverse out-
comes for mother and child both in the short term and in later years, and inrecog-
nition of its imperative to global public health, ‘improving maternal health’ is one
of the United Nations Millennium Development Goals (MDG5). The link between
maternalhealthandthatofthechildiscritical,asstatedintheWHOGlobalStrategy
forInfantandYoungChildFeeding:
Thehealthandnutritionalstatusofmothersandchildrenareintimatelylinked.
Improved infant and young child feeding begins with ensuring the health and
nutritionalstatusofwomen,intheirownright,throughoutallstagesoflifeand
continueswithwomenasprovidersfortheirchildrenandfamilies.Mothersand
infants form a biological and social unit; they also share problems of malnu-
trition and ill-health. Whatever is done to solve these problems concerns both
mothersandchildrentogether.
(WHO,2003,p.5)
A clearer understanding of the relationship between nutrition during the child-
bearing years and health outcomes may provide a basis for developing nutritional
interventionsthatwillimprovepregnancyoutcomesandreducematernalandchild
mortalityandmorbidity.Improvingnutritionduringthiscriticalperiodtopromote
long-term health could also be a driver for future economic growth (World Bank,
2006;SACN,2011).
One of the main challenges for practitioners working in fields allied to maternal
and child nutrition is to translate intricate scientific concepts into simple advice
about food and health that can be easily understood by all members of society. As
ourunderstandingadvances,newcontroversiesandchallengesareintroduced–this
bookprovidesabalancedviewoftheevidencebaseandwillassistreadersincoming
toaclearunderstandingofthesecomplexissues.
The first two chapters in this book set out the nutritional requirements prior
to conception, both in terms of their influence on fertility and in the provision of
adequatenutrientreservesforthemotherandfoetusduringpregnancy.Asillustrated
in these chapters, many women of childbearing age do not meet the recommended
nutrientintakesforkeynutrients,particularlyironandfolate.Althoughhistorically
muchefforthasbeendirectedatinterventionstoimprovematernalnutritionalstatus
that are delivered during mid- or late-gestation, particularly with regard to food
or micronutrient supplementation, there is a growing realisation that the mother’s
nutritional status at and prior to conception exerts strong effects (Williams, 2009).
xii Foreword
Thereisanincreasinginterestinthepotentialthatearlylifeinterventions,including
those around the time of the mother’s own conception (which take into account
powerful intergenerational influences) could offer greater health benefits to both
motherandherchild.
Chapters 6 and 7 in this book clearly illustrate the wide variation in global mi-
cronutrientrecommendationsduringpregnancy.Thesedisparitieshavearisenfrom
the use of different concepts and sometimes different data and because the expert
committees who set the recommendations often base their decisions on judgments
concerning the quality of the available research (Pijls et al., 2009). As national ref-
erence values are reviewed at different time points, decisions may also be based on
different scientific data (Doets et al., 2008). Divergence in the terminology used to
describe reference values also creates difficulties with making comparisons across
countries, leading to confused messages that may have a serious impact on policy
andsignificanthealthconsequences(Pavlovicetal.,2007).
Asnutrientrecommendationsformthebasisoffoodpolicyandfood-baseddietary
guidelines, and are used in nutrition labelling, the need to harmonise recommen-
dations is clear. Chapter 7 describes the EURRECA project, which recognises the
needforevidence-basedpolicymaking,transparentdecision-making,stakeholderin-
volvementandalignmentofpoliciesacrossEurope.TheEURRECAnetworkaimsto
developacommonframeworkthatusesconsistentterminologyinordertodevelop
andmaintainnutrientrecommendationsbasedonthebestcurrentevidence.
Thecrucialroleofmaternalnutritionininfluencingbirthoutcomesisdiscussedin
Chapter8.Asamodifiableriskfactor,maternalnutritionisofhighpublichealthim-
portancewiththepotentialtopreventadversebirthoutcomes,particularlyamongst
developing/low-income populations. Whilsttheevidence fromexperimental animal
studies is strong, the research in humans is much less consistent, due, in part, to
secondaryfactorsthatdifferfromstudytostudy(e.g.baselinematernalnutritional
status,socio-economicstatusofthestudypopulation,timingandmethodsofassess-
ingormanipulatingmaternalnutritionalvariables)(Abu-SaadandFraser,2010).A
further limitation of the usefulness of the evidence base is that most of the studies
investigating maternal nutrition and birth outcomes have approached the issue by
investigatingsinglenutrientsinisolation,andstudiesthataddressandbringtogether
thebroaderpictureofmultiplenutrientintakesordeficienciesarestilllacking.This
work is vital as nutrient deficiencies, generally found amongst low-income popula-
tions, are more likely to involve multiple rather than single deficiencies (Abu-Saad
andFraser,2010).
Theissueofweightgainduringandafterpregnancyremainshighlycontroversial.
AsdescribedinChapter9,almosthalfofallwomenofchildbearingageinEngland
areoverweightorobese,andthisnumberispredictedtorisesignificantlyinthecom-
ing years(NHS,2011). Thispredicament iscompounded by thelack ofknowledge
amongstmothersandhealthprofessionalsabouttherecommendedlevelsofweight
gain and different cultural beliefs and perceptions about weight gain in pregnancy.
In the United Kingdom, at present, there are no formal evidence-based guidelines
fromthegovernmentorprofessionalbodiesonwhatconstitutesappropriateweight
gainduringpregnancy(NICE,2010).
Chapter 10 describes some special cases that may require specific nutritional at-
tention. One of the groups discussed includes adolescent mothers. Approximately
one-fifthofallbirthsworldwidearetoadolescentmothers;thisrepresentsasignifi-
cantglobalpublichealthissue.Reviewshaveshownthattheintakesandnutritional