Nutrition for Childbearing

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Adequate Nutrition: A Key Element In Successful Childbearing

c. 2015 Ann Cowl­in

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Healthy fetal devel­op­ment depends on genet­ics, mater­nal hor­mones, envi­ron­men­tal fac­tors and nutri­tion­al sup­plies. A nutri­tion­al defi­cien­cy or over­dose at a crit­i­cal point con­tributes to poor devel­op­ment. Mom opti­mizes her preg­nan­cy by eat­ing ade­quate pro­tein and drink­ing plen­ty of flu­ids; eat­ing fresh fruits, veg­eta­bles, whole grains and ben­e­fi­cial fats; avoid­ing alco­hol, drugs, caf­feine and tobac­co; and, get­ting reg­u­lar mod­er­ate exer­cise, as well as enough sleep and relax­ation.

Preg­nan­cy nutri­tion begins before con­cep­tion. The B vit­a­mins, folic acid, zinc, pro­tein and omega-3 fat­ty acids are essen­tial pri­or to con­cep­tion and in the first trimester when hyper­pla­sia is pro­nounced and ini­tial organ devel­op­ment is under­way. Dur­ing ges­ta­tion calo­ries, pro­tein and flu­id intake are para­mount. They affect car­dio­vas­cu­lar para­me­ters such as mater­nal blood vol­ume and pres­sure, pla­cen­tal devel­op­ment and nutri­ent trans­port. Fol­low­ing birth, the mother’s recov­ery is depen­dent on the fuels avail­able to repair tis­sue, nour­ish her organs and sup­port breast­feed­ing.

Nutri­tion must be ade­quate to pre­vent low birth weight (LBW) and pre­ma­tu­ri­ty, as well as their sequel­lae of men­tal and phys­i­cal dis­abil­i­ties. Babies born under 5.5 pounds (2500 grams) are con­sid­ered LBW. Most LBW can be elim­i­nat­ed by improved pre­na­tal nutrition–even small reduc­tions in birth weight traced to reduced access to pre­na­tal health care because of race or eco­nom­ic sta­tus [1]. Mod­er­ate aer­o­bic exer­cise also reduces the risk for LBW [2] and mater­nal preeclamp­sia (preg­nan­cy-induced hyper­ten­sion with pro­tein­urea), a gene-linked dis­or­der is aggra­vat­ed by low pro­tein intake, lack of recre­ation­al exer­cise, and stress [3,4]. These two con­di­tions have been on the rise in the U.S. recent­ly. Tech­nol­o­gy is improv­ing sur­vival rates for these con­di­tions, but pre­na­tal care, nutri­tion and mod­er­ate exer­cise are keys to their pre­ven­tion. Atten­tion to these fac­tors results in a healthy moth­er and — in the absence of genet­ic abnor­mal­i­ties, uncon­trol­lable envi­ron­men­tal fac­tors or acci­dents — healthy moth­ers have healthy babies. Healthy babies born at full term are the goal.

What is Adequate Nutrition for a Childbearing Woman?

Pro­teins, car­bo­hy­drates, fats, vit­a­mins, min­er­als and water are all nec­es­sary to achieve ade­quate nutri­tion in preg­nan­cy. Extra calo­ries are not required in the first trimester, accord­ing to the Insti­tute of Med­i­cine [1]. Height, weight, activ­i­ty lev­el and nutri­tion­al stress fac­tors, plus about 300 extra calories/day in the 2nd trimester and about 500 extra in the 3rd trimester deter­mine calo­rie require­ments. Nutri­tion­al stress fac­tors are nau­sea, vom­it­ing and weight loss for a pro­longed peri­od, preg­nan­cy spac­ing less than one year apart, pri­or poor obstet­ri­cal out­comes (still­births, spon­ta­neous abor­tions, preterm deliv­er­ies), fail­ure to gain ade­quate weight, age under 20 years, and emo­tion­al stress. For each stress fac­tor add an addi­tion­al 200 calo­ries (400 extra calo­ries max­i­mum) [5, p. 607]. Calo­rie require­ments will need to be refig­ured dur­ing preg­nan­cy since very ath­let­ic women may become less active, there will be weight gain and/or loss, and there may be chang­ing stress fac­tors affect­ing the for­mu­la.

Macronutrients

Approx­i­mate­ly 20–25% of calo­ries in pro­tein, 45–55% in car­bo­hy­drate and 30% in fat is an effec­tive bal­ance of macronu­tri­ents for insur­ing a steady lev­el of blood sug­ar and nutri­ents. Con­sum­ing mini-meals of a few hun­dred calo­ries every two to three hours is effec­tive for clients who wish to avoid errat­ic ener­gy states. Due to the meta­bol­ic pref­er­ence to meet the fetal demand for ener­gy and the ten­den­cy toward pre­na­tal hyper­in­su­line­mia, this strat­e­gy helps pre­vent blood sug­ar fluc­tu­a­tions.

Pro­tein. Pro­tein is need­ed for growth of the uterus, pla­cen­ta and breast tis­sue, for pro­duc­tion of amni­ot­ic flu­id and a 40% or more increase in mater­nal blood vol­ume, for stor­age reserves for labor, birth and breast­feed­ing, and to facil­i­tate rapid fetal tis­sue growth. Ade­quate pro­tein assists in mag­ne­sium reten­tion, which reduces the risk for and/or sever­i­ty of preg­nan­cy-induced hyper­ten­sion (PIH). Pro­tein sources can con­tain com­plete or incom­plete pro­teins; veg­e­tar­i­ans must take care to include suf­fi­cient quani­ti­ties and effi­cient com­bi­na­tions of incom­plete pro­teins.

Pro­fes­sion­al view­points vary as to how much pro­tein is nec­es­sary in preg­nan­cy. Kline rec­om­mends 0.8 gm pro­tein per kg of body weight, plus 10 grams per day [6], in keep­ing with rec­om­men­da­tions by the Amer­i­can Col­lege of Obste­tri­cians and Gyne­col­o­gists (ACOG) for an extra10 grams per day [7], and notes that women who are very active or under 14 years may require 1.0 gm of pro­tein per kg of body weight. In this case, a 135 pound preg­nant woman would require 60 to 70 grams of pro­tein per day. How­ev­er, there are oth­er points of view [5, pp. 601–608], based on the fact that as much as 30% of pro­tein intake may be stored dur­ing preg­nan­cy and some bro­ken down for fuel if total caloric intake is inadquate. Dai­ly pro­tein intakes of 25 to 30 grams per fetus beyond non-preg­nan­cy lev­els are more like­ly need­ed [8]. This equates to 70 to 90 grams of pro­tein per day for an aver­age Amer­i­can woman with a sin­gle­ton preg­nan­cy. By adding 25 to 30 grams of pro­tein per day to her needs based on weight and activ­i­ty lev­el, and tak­ing in suf­fi­cient total calo­ries (her oth­er needs plus 300 calo­ries per day), an ath­let­ic preg­nant woman can be assured that she will pro­vide ade­quate pro­tein.

Car­bo­hy­drates. Com­plex car­bo­hy­drates and fiber foods such as fresh fruits, veg­eta­bles and whole grains are the most desir­able imme­di­ate ener­gy sources for preg­nant women, as they also pro­vide vit­a­mins and minerals.For women with­out car­bo­hy­drate intol­er­ance, sim­ple and com­plex car­bo­hy­drates pro­vide imme­di­ate, usable blood sug­ar. How­ev­er, women with dia­betes or ges­ta­tion­al dia­betes should fol­low the direc­tions of their care provider.

Fats. Fetal fat­ty acids are pro­vid­ed sole­ly by mater­nal sup­plies. Omega-3 fat­ty acids–alpha-lineolenic acid (ALNA), eicos­apen­taenoic acid (EPA) and docosa­hexaenoic acid (DHA)–are impor­tant con­stituents of the pre­na­tal diet. Insuf­fi­cient lev­els of DHA are asso­ci­at­ed with impaired vision, ner­vous sys­tem dis­or­ders, low birth weight and pre­ma­ture deliv­ery [9–11]. There is some evi­dence that dur­ing preg­nan­cy mater­nal DHA lev­els fall and the poten­tial for devel­op­ing a defi­cien­cy increas­es [12]. Sup­pli­men­ta­tion of mater­nal intake of omega-3 fat­ty acids has been shown to increase fetal DHA lev­els [13]. By alter­ing the omega-3 fat­ty acid con­tent of cells through dietary changes, the risk of preeclamp­sia may be reduced. Williams found that women with the low­est lev­els of omega-3 fat­ty acids were 7.6 times more like­ly to have preeclamp­sia com­pared to those with the high­est lev­el [14]. Although fish are an excel­lent source of DHA and EPA (pre­cur­sor of DHA), one needs to know where the fish comes from and whether there is any con­t­a­m­i­na­tion asso­ci­at­ed with those waters, par­tic­u­lar­ly mer­cury or lead. Omega-6 fats–available through nuts, seeds and veg­eta­bles, and their oils–aid the absorp­tion of vit­a­mins A, D, E, K and cal­ci­um, all of which are uti­lized in fetal devel­op­ment.

Micronutrients

Ade­quate lev­els of all vit­a­mins and min­er­als are impor­tant in preg­nan­cy. By eat­ing a broad-based and col­or­ful diet of whole foods, most of these micronu­tri­ents will be present. But, mod­ern food con­sump­tion does not always allow for this. To pre­vent vit­a­min or min­er­al defi­cien­cies women are asked by their care provider to take pre­na­tal vit­a­mins and/or min­er­als. To aid absorp­tion, it is some­times rec­om­mend­ed that women take them on an emp­ty stom­ach. How­ev­er, this strat­e­gy can induce nau­sea and vom­it­ing. These pills can be cut in small por­tions and tak­en with food through­out the day. Women tak­ing iron pills who have con­sti­pa­tion may be dehy­drat­ed. Dark stools indi­cate poor iron absorp­tion; tak­ing iron pills with vit­a­min C and flu­ids may help.

Vit­a­min A has been shown to have harm­ful effects when over-dosed. In one study, vit­a­min A intake above 10,000 IU dai­ly result­ed in birth defects of the head, heart, brain or spinal cord [15]. Vit­a­min B6 is help­ful in pre­vent­ing nau­sea and vom­it­ing, and poor appetite. Women who avoid milk, eggs and fish should be con­sid­ered for vit­a­min D sup­pli­men­ta­tion dur­ing preg­nan­cy and lac­ta­tion [16]. Vit­a­min K is nec­es­sary for pro­duc­tion of pro­throm­bin, which is required for blood clot­ting. Fol­low­ing deliv­ery, women with vit­a­min K defi­cien­cies, ane­mia or oth­er clot­ting prob­lems may hem­or­rhage, which is the pri­ma­ry cause of mater­nal mor­tal­i­ty.

The great­est need for cal­ci­um comes in the third trimester. At 35 weeks, 330 mg/day is trans­ferred from moth­er to fetus [17]. Low lev­els of both cal­ci­um and mag­ne­sium are asso­ci­at­ed with preeclampsia.The role of mag­ne­sium appears to be asso­ci­at­ed with its func­tion as an acti­va­tor of enzymes involved in mem­brane trans­port and integri­ty, and with its rela­tion­ship to prostaglandins–specifically, the ratio of prosta­cy­clins (vasodila­tors) and throm­box­anes (some of which are vaso­con­stric­tors), which is dra­mat­i­cal­ly altered in the case of low serum mag­ne­sium. Both prosta­cy­clin and throm­box­ane sub­stances are increased dur­ing a nor­mal preg­nan­cy. How­ev­er, women who devel­op preeclamp­sia have much small­er increas­es in prosta­cy­clin pro­duc­tion than oth­er women, while throm­box­ane con­tin­ues to rise at the same rate, thus increas­ing vaso­con­stric­tion and rais­ing blood pres­sure.

Neona­tal hypothy­roidism is linked to mater­nal iodine defi­cien­cy. Some foods block iodine uptake when eat­en raw in large amounts, includ­ing brus­sels sprouts, cab­bage, cau­li­flower, kale, peach­es, pears, spinach and turnips.While iron’s major func­tion is bind­ing oxy­gen to red blood cells (RBCs) for trans­port to oxy­gen-requir­ing sites, a phe­nom­e­non known as phys­i­o­log­ic ane­mia can occur in preg­nan­cy because plas­ma increas­es at a high­er rate than RBCs. Iron defi­cien­cy can be due to low dietary intake or oth­er caus­es, includ­ing inter­nal bleed­ing, high phos­pho­rous intake or pro­longed antacid use. Sodi­um is vital to main­tain­ing an ade­quate mater­nal blood vol­ume. It is now well-estab­lished that preg­nant women should salt to taste [18] and should not take diruret­ics. When severe ede­ma occurs, the health care provider will look at blood pres­sure. Some ede­ma is the nat­ur­al con­se­quence of the increased hor­mon­al lev­els asso­ci­at­ed with preg­nan­cy; how­ev­er, severe ede­ma is a clas­sic symp­tom of preeclamp­sia.

Fluids

Dur­ing preg­nan­cy water does extra duty, help­ing to main­tain an increased mater­nal blood vol­ume, cool­ing both organ­isms (moth­er and fetus), and car­ry­ing off waste from increased meta­bol­ic func­tions. Eight 8-ounce glass­es of water is the com­mon­ly accept­ed amount to be con­sumed dai­ly. Ath­let­ic women need more and preg­nant women liv­ing at high alti­tudes may need to con­sume twice this amount. While sports drinks may be use­ful for those with an intense or long dura­tion work load, a snack con­sumed about an hour pri­or to exer­cise and water or watered-down 100% juice con­sumed dur­ing the work­out may be prefer­able for the recre­ation­al exer­cis­er.

The impor­tance of water tak­en reg­u­lar­ly dur­ing exer­cise can­not be over-empha­sized. A few ounces con­sumed every ten or fif­teen min­utes dur­ing intense work is advis­able. Ath­letes should drink water until their urine is clear. If women have ques­tions about the safe­ty of their tap water, they should con­tact their local health depart­ment or the Water Qual­i­ty Asso­ci­a­tion [19].

Conditions and Situations That May Affect Energy Balance

The val­ue of ade­quate nutri­tion and an active preg­nan­cy is evi­dent in the results: a healthy, well-devel­oped infant, and a healthy moth­er. Eat­ing dis­or­ders, preg­nan­cy-induced hyper­ten­sion, ane­mia, or age-relat­ed fac­tors can lead to adverse effects. Post­na­tal dis­tress can be asso­ci­at­ed with body weight and shape con­cerns, dis­or­dered eat­ing before and dur­ing preg­nan­cy, and vom­it­ing dur­ing preg­nan­cy [20]. Low inten­si­ty exer­cise dur­ing ear­ly preg­nan­cy can play a pro­tec­tive role. The most dis­tressed moth­ers suf­fer from an eat­ing dis­or­der at the time of preg­nan­cy. Binge and/or purge eat­ing dis­or­ders are asso­ci­at­ed with more dis­tress than a food restric­tion type of dis­or­der.

Nau­sea and vom­it­ing are fair­ly com­mon in ear­ly preg­nan­cy, but usu­al­ly improve around the twelfth week. There are two major the­o­ries con­cern­ing nor­mal nau­sea and vom­it­ing in preg­nan­cy. One regards the effects of altered hor­mone lev­els on the sens­es, emet­ic cen­ters in the brain stem and gas­tric func­tion, and on plas­ma glu­cose lev­els; and the oth­er the­o­ry con­cerns aller­gic respons­es to pos­si­ble envi­ron­men­tal and food tox­ins [21–25]. Women in one research cohort with no symp­toms of nau­sea or vom­it­ing in ear­ly preg­nan­cy showed a sign­f­i­cant­ly high­er pro­por­tion of fetal death than among those with nau­sea or vom­it­ing [26]. Such a find­ing gives impe­tus to the con­ven­tion­al wis­dom that nor­mal “morn­ing sick­ness” is a sign of a healthy preg­nan­cy. In prac­tice, help­ing women through ear­ly preg­nan­cy nau­sea and vom­it­ing involves find­ing out which pro­teins they can eat and retain, to drink plen­ty of flu­ids and to main­tain elec­trolyte bal­ance. Sports drinks with 6 to 8% car­boy­h­drate can be help­ful. Some women also find mod­er­ate exer­cise help­ful. Eat­ing plen­ty of pro­tein and eat­ing small quan­ti­ties often can alle­vi­ate nau­sea caused by fluc­tu­at­ing blood sug­ar.

When vom­it­ing con­tin­ues and is severe, affect­ing elec­trolyte bal­ance, nutri­tion­al sta­tus and weight gain, the term hyper­eme­sis gravi­darum applies. It is not always clear whether there is an under­ly­ing phys­i­cal con­di­tion, and/or an asso­ci­at­ed behav­ioral prob­lem. Even when a vari­ety of phar­ma­co­log­i­cal alter­ations have been tried, some women con­tin­ue to be sick. Some non-phar­ma­co­log­i­cal treat­ments have been found effec­tive, includ­ing the use of pow­dered gin­ger [27], vit­a­min B6 [28], hyp­no­tism [29], and accu­pres­sure [30].

Repeat­ed inges­tion of non-food sub­stances dur­ing preg­nan­cy is called pica. In the US, the most com­mon items eat­en are clay, corn starch, laun­dry starch, ice, dirt and bak­ing soda. Women at great­est risk are black women liv­ing in a rur­al set­ting; white, urban women who ingest items such as ice, ash­es and oth­er sub­stances, are known about, but less stud­ied [31]. Cul­ture and tra­di­tion appear to play a role, with fam­i­ly his­to­ry being a risk fac­tor. In one report of a rur­al mid­west set­ting of 300 low-income post­par­tum women, 65% ate one or more pica sub­stances dur­ing preg­nan­cy [32]. Because non-nutri­ent items are sub­sti­tut­ed for food, pica inter­feres with a healthy nutri­tion­al sta­tus and can con­tribute to ane­mia, eclamp­sia and min­er­al defi­cien­cies [31,33,34]. Aware­ness of pica by health and fit­ness pro­fes­sion­als is a step toward locat­ing and help­ing women with this dis­or­der.

Alco­hol, smok­ing and drugs have all been shown detri­men­tal to the fetus. A woman wish­ing to have a healthy baby will avoid them. Fetal alco­hol syn­drome (FAS) can result in a vari­ety of con­gen­i­tal mal­for­ma­tions, growth restric­tion and neu­ro­log­i­cal impair­ments. The organs affect­ed by FAS devel­op ear­ly when a woman may not be aware she is preg­nant, so avoid­ing alco­hol for a peri­od of time before con­cep­tion is wise. Smok­ing is a major con­trib­u­tor to growth restric­tion and asth­ma in chil­dren. Drugs cross the pla­cen­tal bar­ri­er and are par­tic­u­lar­ly dan­ger­ous to the fetal liv­er. All of these items inter­fere with nutri­ent uti­liza­tion.

Hyper­ten­sive dis­or­ders in preg­nan­cy are the most com­mon med­ical com­pli­ca­tion. Preg­nan­cy induced hyper­ten­sion (PIH) is defined as ele­vat­ed blood pres­sure after 20 weeks of ges­ta­tion in women who did not have ele­vat­ed blood pres­sure pri­or to preg­nan­cy. In some women this may be an ear­ly sign of preec­plamp­sia. Women with chron­ic hyper­ten­sion pri­or to preg­nan­cy or blood pres­sure at least 140/90 before 20 weeks ges­ta­tion, are at increased risk for preeclamp­sia. The devel­op­ment of pro­tein­uria, in addi­tion to hyper­ten­sion, is a sign of preeclamp­sia, and gen­er­al­ly occurs after 20 weeks as well, although changes in the vas­cu­lar sys­tem may occur by week 14, includ­ing increased periph­er­al vas­cu­lar resis­tance, reduced car­diac out­put, reduced plas­ma vol­ume, and decreased glomeru­lar fil­tra­tion rate with reten­tion of salt and water [35]. As a result, there is reduced per­fu­sion of the pla­cen­ta and mater­nal kid­neys, liv­er and brain. The fetus can suf­fer intrauter­ine growth restric­tion (IUGR) and even hypox­ia. Altered fat­ty acid com­po­si­tion, in addi­tion to vasospasm and oth­er vas­cu­lar symp­toms, explain the hyper­lipi­demia, antiox­i­dant defi­cien­cy, coag­u­la­tion dif­fi­cul­ties and ischemia or infarc­tions of the uterus and pla­cen­ta that occur in preeclamp­sia [14,36]. At the end-stage of this dis­or­der, eclamp­sia (also called tox­emia), the moth­er can suf­fer con­vul­sions, organ fail­ure and death. Eclamp­sia is the third lead­ing cause of mater­nal mor­tal­i­ty [35].

Fac­tors oth­er than nutri­tion under­ly PIH and preeclamp­sia, but nutri­tion can be a fac­tor in the sever­i­ty of such dis­or­ders. There is an asso­ci­a­tion of mal­nu­tri­tion, low­er socioe­co­nom­ic sta­tus and lack of edu­ca­tion, as well as an asso­ci­a­tion of stress and mal­nu­tri­tion, with increased risk of preeclamp­sia. Fol­low­ing a nutri­tion­al plan that includes ade­quate pro­tein, par­tic­u­lar­ly ear­ly in preg­nan­cy, is one guide­line usu­al­ly giv­en to women as a means of reduc­ing the risk of devel­op­ing severe hyper­ten­sion. Espe­cial­ly women with a per­son­al his­to­ry or fam­i­ly his­to­ry of hyper­ten­sive dis­or­ders need to take care to eat a healthy diet, include reg­u­lar exer­cise in their rou­tine and prac­tice stress man­age­ment.

Ane­mia includes phys­i­o­log­ic ane­mia and per­ni­cious ane­mias, such as cycle cell ane­mia or defi­cien­cies in iron, B12 or folic acid, that affect the abil­i­ty of red blood cells (RBCs) to adhere oxy­gen. Ane­mia is gen­er­al­ly con­sid­ered to be a hemo­glo­bin lev­el below 10 g/dL in the preg­nant pop­u­la­tion [37]. If there is a seri­ous hemo­glo­bin pathol­o­gy, exer­tion is like­ly to be con­traindi­cat­ed. On the oth­er hand, if there is mild ane­mia that responds to iron tak­en in con­junc­tion with Vit­a­min C, or to B12 or folic acid, it is not like­ly to require more than a tem­po­rary reduc­tion of activ­i­ties. It is impor­tant to note that hemo­glo­bin lev­els in African-Amer­i­cans are gen­er­al­ly about 1 g/dL low­er than those for whites, regard­less of socioe­co­nom­ic group [38]. Sick­le cell dis­ease occurs most fre­quent­ly in African-Amer­i­cans. Glu­cose-6-Phos­phate Dehy­dro­ge­nase (G6PD) defi­cien­cy also occurs in African-Amer­i­cans, as well as in those of Mediter­ranean descent [39].

It could be said that the ide­al child­bear­ing peri­od of a woman’s life runs from the time she becomes phys­i­cal­ly mature (late teens to ear­ly twen­ties) to the time her lifestyle habits have dra­mat­i­cal­ly affect­ed her health sta­tus (mid-thir­ties). Child­bear­ing before or after this peri­od auto­mat­i­cal­ly places a preg­nant woman in a high risk cat­e­go­ry. Before matu­ri­ty, her nutri­tion­al intake must cov­er her own growth needs as well as those of her baby. As mid-life approach­es, a woman may already have defi­cien­cies that need to be assessed so that her dietary intake can min­i­mize any detri­ment. For exam­ple, if her intake of cal­ci­um has been poor for many years, she will be at increased risk for osteo­poro­sis if care is not tak­en to improve cal­ci­um intake.

How Adequate Nutrition Supports a Healthy Pregnancy

Build­ing a healthy pla­cen­ta, a strong uterus and a healthy baby, as well as pro­tect­ing mater­nal nuti­tion­al stores, all rely on the mother’s dietary intake. Blood vol­ume expan­sion makes ade­quate pla­cen­tal devel­op­ment pos­si­ble. From a nutri­tion­al per­spec­tive, this means ade­quate pro­tein and flu­ids to pro­duce extra blood, as well as ener­gy (calo­ries) for the expres­sion of hor­mones that direct pla­cen­tal devel­op­ment. Pro­duced by the implan­ta­tion of the embryo’s cir­cu­la­to­ry mech­a­nism into the uter­ine cir­cu­la­tion, the pla­cen­ta is the locus of nutri­ent exchange between moth­er and fetus.

Oxy­gen, car­bon diox­ide, water, elec­trolytes and many vit­a­mins and min­er­als are exchanged across the pla­cen­tal barrier–or membrane–by sim­ple, or pas­sive, dif­fu­sion. These sub­stances flow from greater to less­er con­cen­tra­tion. Nutri­ents in this cat­e­go­ry need to be present in suf­fi­cient quan­ti­ties in the mother’s blood stream for sim­ple dif­fu­sion to be effec­tive. Glu­cose is trans­port­ed by facil­i­tat­ed dif­fu­sion, as the fetus must have glu­cose for ener­gy. It is aid­ed in its trans­port across the pla­cen­tal bar­ri­er by its mol­e­c­u­lar con­fig­u­ra­tion, even if mater­nal con­cen­tra­tion is not much greater than fetal con­cen­tra­tion. With­out ade­quate ener­gy, pla­cen­tal devel­op­ment is stunt­ed, plac­ing the baby at risk. Cer­tain nutrients–amino acids, cal­ci­um, iron, potas­si­um, phos­pho­rus and vit­a­min B6–require active trans­port, an ener­gy-requir­ing sys­tem. If these are not present in quan­ti­ties that are ade­quate for both moth­er and baby, the fetus will use mater­nal stores, plac­ing the moth­er at risk. If quan­ti­ties are too low, both will suf­fer.

The uterus must grow from the size of a pear to that of a water­mel­on, and yet main­tain the strength required for eight, twelve, or more hours of labor. To do this, the col­la­gen that con­nects the mul­ti­pen­nate mus­cle fibers of the uterus must stretch and the fibers them­selves must main­tain integri­ty. Pro­tein, iron, zinc and vit­a­min C are par­tic­u­lar­ly impor­tant with respect to these aspects of uter­ine devel­op­ment and activ­i­ty.

Ade­quate mater­nal calo­rie and pro­tein con­sump­tion are the pri­ma­ry con­cerns in assur­ing there is suf­fi­cient nutri­tion to cre­ate a healthy baby [39]. These are essen­tial to pre­vent low birth weight, a small for ges­ta­tion­al age (SGA) baby, pre-term deliv­ery and a num­ber of oth­er con­di­tions. Good nutrition–that is, nutri­tion con­tain­ing ade­quate amounts of a range of nutrients–is essen­tial to pro­duce opti­mal brain and organ devel­op­ment, as well as impor­tant func­tions such as stor­age of iron in the fetal liv­er.

The effects of poor nutri­tion in the first trimester include poor fetal devel­op­ment, a lighter and small­er pla­cen­ta, pre­ma­tu­ri­ty and low birth weight, low­er Apgar scores and mater­nal ane­mia. Dur­ing the sec­ond and third trimester, poor nutri­tion has a neg­a­tive effect on the baby’s growth, includ­ing devel­op­ment of the ner­vous sys­tem, and con­tributes to preg­nan­cy-induced hyper­ten­sion (PIH). The state of mater­nal nutri­tion in the months lead­ing up to preg­nan­cy also plays a role in fetal devel­op­ment, such as the need for ade­quate folic acid [40]. A defi­cien­cy can result in impaired cell divi­sion, mega­loblas­tic ane­mia, and a num­ber of sequel­lae includ­ing fetal mal­for­ma­tion (includ­ing neur­al tube defects), spon­ta­neous abor­tion, eclamp­sia, pre-term deliv­ery, SGA and pre­na­tal hem­or­rhage [9].

The fetus places sub­stan­tial demands on the mother’s body dur­ing preg­nan­cy. The liv­er must pro­duce albu­min, the osmot­ic sub­stance that draws flu­id from cells into the blood stream in order to pro­duce the large blood vol­ume required to sus­tain a pla­cen­ta and fetus. The kid­neys work to fil­ter the addi­tion­al blood vol­ume. The brain and glands pro­duce high lev­els of repro­duc­tive hor­mones. Raw mate­ri­als are need­ed for the array of meta­bol­ic func­tions required in preg­nan­cy, and ade­quate nutri­tion pro­tects mater­nal health by pro­tect­ing her ener­gy resources.

Maternal Weight Gain

Mater­nal weight gain has tra­di­tion­al­ly been used to eval­u­ate the state of a preg­nan­cy. As of 2009, the Nation­al Acad­e­my of Sci­ence [1] rec­om­mends that preg­nan­cy weight gain be based on a woman’s pre-preg­nan­cy BMI.  The Nation­al Heart, Lung and Blood Insti­tute pro­vides a BMI cal­cu­la­tor here: http://www.nhlbisupport.com/bmi/. A pre-preg­nan­cy BMI less than 18.5 (low) should have a total weight gain of 28 to 40 pounds (12.7 to 18 kg); BMI between 18.5–24.9 (nor­mal) should gain 25 to 35 pounds (11.3 to 16 kg); and those BMI 25.0 to 29.9 (high) should gain 15 to 25 (6.8 to 11.3 kg) pounds. Weight gain for obese women (BMI over 30.0) should be lim­it­ed to 11 pounds.

First trimester weight gain usu­al­ly ris­es at a slow­er pace than sec­ond or third trimester gain and may be neg­a­tive­ly influ­enced by nau­sea and vom­it­ing. When dietary intake is based on ade­quate calo­ries and pro­tein, weight gain should be in the cor­rect range for an indi­vid­ual woman, unless there is an under­ly­ing med­ical con­di­tion. Ultra­sound imag­ing is now used by health care providers as much as weight gain or fun­dal height (the mea­sure­ment from pubic bone to top of the uterus) to deter­mine if fetal growth is pro­gress­ing at a sat­is­fac­to­ry rate.

And don’t for­get to get your dai­ly Preg­nan­cy Nutri­tion Check­list!

References

1. Nation­al Acad­e­my of Sci­ence, Insti­tute of Med­i­cine, Com­mit­tee on Nutri­tion­al Sta­tus Dur­ing Preg­nan­cy and Lac­ta­tion. 1991 and 2009. Nutri­tion Dur­ing Preg­nan­cy. Wash­ing­ton, DC: Nation­al Acad­e­my Press.

2. Leifer­man JA. Even­son KR. 2003.The effect of reg­u­lar leisure phys­i­cal activ­i­ty on birth out­comes. Mater­nal & Child Health Jour­nal. 7(1):59–64

3. Sorensen TK. Williams MA. Lee IM. Dashow EE. Thomp­son ML. Luthy DA. 2003. Recre­ation­al phys­i­cal activ­i­ty dur­ing preg­nan­cy and risk of preeclampsia.Hypertension. 41(6):1273–80.

4. Yeo, S and Davidge, ST. 2001. Pos­si­ble ben­e­fi­cial effect of exer­cise by reduc­ing oxida­tive stress, on the inci­dence of preeclamp­sia [Review]. Jour­nal of Wom­enÕs Health & Gen­der-Based Med­i­cine 10(10):983–989.

5. Var­ney, H, Kriebs, JM and Gegor, CL (eds). 2003 Varney’s Mid­wifery, 4th ed. Boston: Jones & Bartlett.

6. Kline, DA. 2003. Nutri­tion for Women, Part I: Sex­u­al and Repro­duc­tive Health. 6th edi­tion. Eure­ka, CA: Nutri­tion Dimen­sion.

7. Amer­i­can Col­lege of Obste­tri­cians and Gyne­col­o­gists. 1993. Nutri­tion dur­ing preg­nan­cy. ACOG Tech­ni­cal Bul­letin no. 179. Wash­ing­ton, DC: ACOG.

8. Women’s Edu­ca­tion Life Learn­ing (WELL) at Yale-New Haven Hos­pi­tal. Pro­tein Counter. 1998.

9. Net­tle­ton, JA. 1993. Are Omega-3 fat­ty acids essen­tial nutri­tion for fetal and infant devel­op­ment? JADA 93(1): 58–66.

10. Fore­man-van Dron­ge­len, M, van­Houwelin­gen, AC, Kester, ADM, et al. 1995. Long-chain polyun­sat­u­rat­ed fat­ty acids in preterm infants: sta­tus at birth and its influ­ence on post­na­tal levels,J Ped 126(4): 611–18.

11. Olsen, SF, Sorensen, JD, et al. 1992. Ran­dom­ized con­trolled tri­al of effect of fish oil sup­ple­men­ta­tion on preg­nan­cy dura­tion, Lancet 339: 1003–7.

12. Hol­man, RT, John­son, SB and Ogburn, PL. 1991. Defi­cien­cy of essen­tial fat­ty acids and mem­brane flu­id­i­ty dur­ing preg­nan­cy and lac­ta­tion, Proc Nat Acad Sci 88: 4835–39.

13. Con­ner, WE, Lowen­sohn, R and Hatch­er, L. 1996. Increased doosa­hexaenoic acid lev­els in human new­born infants by admin­stra­tion of sar­dines and fish oil dur­ing preg­nan­cy, Lipids 31 (sup­pl): 183S-87S.

14. Williams, MA, Zingheim, RW and King, IB. 1995. Omega-3 fat­ty acids in mater­nal ery­thro­cytes and risk of preeclamp­sia, Epi­demi­ol 6(3): 232–37.

15. Roth­man, KJ, Moore, LL, Singer, MR et al. 1995. Ter­ato­genic­i­ty of high vit­a­min A intake, NEJM 333(21): 1269–1373.

16. Speck­er, BL. 1994. Do North Amer­i­can wmen need sup­ple­men­tal vit­a­min D dur­ing preg­nan­cy and lac­ta­tion? Am J Clin Nutr 59(suppl): 484S-491S.

17. Forbes, GB. 1976. Cal­ci­um accu­mu­la­tion by the human fetus, Pedi­atrics 57: 976–7.

18. Brew­er, GS and Brew­er, TH. 1983. The Brew­er Med­ical Diet for Nor­mal and High-Risk Preg­nan­cy. NY: Simon and Schus­ter.

19. Water Qual­i­ty Asso­ci­a­tion, 4151 Naperville Road, Lisle, IL 60532. Phone 708–505-0160.

20. Abra­ham S., Tay­lor A. and Con­ti J. 2001. Post­na­tal depres­sion, eat­ing, exer­cise, and vom­it­ing before and dur­ing preg­nan­cy. Inter­na­tion­al Jour­nal of Eat­ing Dis­or­ders. 29(4):482–7.

21. Erick, M. 1995. Hyper­ol­fac­tion and hyper­eme­sis gravi­darum: what is the rela­tion­ship? Nutr Rev 53(10): 289–95.

22. Pro­fet, M. 1991. The func­tion of aller­gy: immuno­log­i­cal defense against tox­ins, Q Rev Biol 66(1): 23–62.

23. Koch, KL, Stern, RM, Vasey, M, Bot­ti, JJ, Creasy, GW and Dwyer, A. 1990. Gas­tric dys­rhyth­mias and nau­sea of preg­nan­cy, Diges­tive Dis­eases Sci 35(8): 961–8.

24. Vel­la­cott, ID, Cooke, EJA and James, CE. 1988. Nau­sea and vom­it­ing in ear­ly preg­nan­cy, Intl J Gyn Ob 27: 57–62.

25. Dilo­rio, C. 1988. The man­age­ment of nau­sea and vom­it­ing in preg­nan­cy, Nurse Prac 13(5); 23–8.

26. Tier­son, FD, Olsen, CL and Hook, EB. 1986. Nau­sea and vom­it­ing preg­nan­cy and asso­ci­a­tion with preg­nan­cy out­come, Am J Ob Gyn 155(5): 1017–22.

27. Fis­ch­er-Ras­mussen, W, Kjaer, SK, Dahl, C and Asp­ing, U. 1990. Gin­ger treat­ment of hyper­eme­sis gravi­darum, Eur J Ob Gyn Reprod Biol 38: 19–24.

28. Sahakia, V, Rouse, D, Sipes, S, Rose, N and Niegyl, J. 1991. Vit­a­min B6 is effec­tive ther­a­py for nau­sea and vom­it­ing of preg­nan­cy: a ran­dom­ized, dou­ble-blind place­bo-con­trolled study, Ob Gyn 78(1): 33–6.

29. Apfel, RJ, Kel­ley, SF and Frankel, FH. 1986. The role of hyp­no­ti­z­abil­i­ty in the patho­gen­e­sis and treat­ment of nau­sea and vom­it­ing in preg­nan­cy, J Psy­cho­som Ob Gyn 5:179–86.

30. DeAloy­sio, D and Penac­chioni, P. 1992. Morn­ing sick­ness con­trol in ear­ly preg­nan­cy by Neiguan point acu­pres­sure, Ob Gyn 80(5): 852–4.

31. Horner, RD, Lack­ey, CJ, Kolasa, K and War­ren, K. 1991. Pica prac­tices of preg­nant women, JADA 91(1): 34–8.

32. Bar­ton, JR, Riely, CA, and Sibai, BM. 1992. Bak­ing pow­der pica mim­ic­k­ing preeclamp­sia, Am J Ob Gyn 167(1): 98–9.

33. Cook­sey, NR. 1995. Pica and olfac­to­ry crav­ing of preg­nan­cy: how deep are the secrets? Birth 22(3): 129–37.

34. Dan­ford, ED. 1982. Pica and nutri­tion, Ann Rev Nutr 2: 303–22.

35. New­man, V and Fuller­ton, JT. 1990. The role of nutri­tion in the pre­ven­tion of preeclamp­sia, review of the lit­er­a­ture, JNM 35(5): 282–291.

36. Sibai, BM, Gor­don, T, Thom, E et al. 1995. Risk fac­tors for preeclamp­sia in healthy nul­li­parous women: a prospec­tive study, Am J Ob Gyn 172: 642–48.

37. Reedy, NJ and Var­ney, H. 1996. Screen­ing for and col­lab­o­ra­tive man­age­ment of antepar­tal com­pli­ca­tions, in Var­ney, ed.,VarneyÕs Mid­wifery, 3rd ed., Boston: Jones & Bartlett.

38. Pay­ton, RG and White, PJ. 1995. Pri­ma­ry care for women: assess­ment of hema­to­log­ic dis­or­ders, JNM 40(2): 120–36.

39. Var­ney, H. 1996. Varney’s Mid­wifery, 3rd ed. Boston: Jones & Bartlett, p. 319.

40. Hine, RJ. 1996. What prac­ti­tion­ers need to know about folic acid, JADA 96(5): 441–2.

2 Comments

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    April 30, 2014 @ 1:23 pm

    […] dis­or­ders, she may be able to reduce the sever­i­ty by stay­ing fit, well nour­ished and well rest­ed. A bal­anced and col­or­ful diet, along with avoid­ance of alco­hol, drugs and unsafe behav­iors are […]

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    June 17, 2016 @ 8:25 am

    […] explains that preg­nant women need to eat a bal­anced diet that includes pro­teins, car­bo­hy­drates, fats, vit­a­mins, min­er­als and water. She adds that women […]