Showing posts with label Nutrition and pregnancy. Show all posts
Showing posts with label Nutrition and pregnancy. Show all posts

Wednesday, August 18

School Nutrition

School Nutrition,
A school meal is a meal (usually lunch or dinner) provided to students at a school. It is usually served at sometime around noon; however, many also serve breakfast before classes begin in the mornings. The purpose is to ensure the proper nutrition and health of children, so that they may learn more effectively.
Some schools have theme days whereby food is served in a particular style. For example, the school might serve Chinese cuisine to celebrate the Chinese New Year. There may also be weekly recurring themes, such as "Taco Tuesdays", "Macaroni Mondays," or pizza at the end of the week.


School Nutrition by country

Canada
Canada has no national school meal program, and elementary schools are usually not equipped with kitchen facilities. Parents are generally expected to provide a packed lunch for their child to take to school, or have their child return home for the duration of the lunch period.
However, some non-profit organisations dedicated to student nutrition programs do exist.

Finland
Free school dinners in elementary and secondary schools have been served nationwide since October 9, 1948. In some cities poor people were offered free school dinners from the beginning of the 20th century (eg. from 1902 in Kuopio, extending to all students in 1945).
In Finland also the lunches in Higher Education are subsidized. The Social Insurance Institution of Finland compensates 0,67 euros per student's daily meal. The meals served are to be as healthy and nutritionally balanced as possible.
Special diets based on religious, cultural or ethical choices or restrictions due to allergies are served with no extra cost.

India,
Mid-day Meal Scheme,
Under the Integrated Child Development Services (ICDS), government schools and partially-aided schools, along with Anganwadis, provide mid-day meals to the students attending such institutions, known as the Mid-day Meal Scheme. The meals served are free of cost and meet guidelines that have been set by the policy. The history of the program can be traced to 1925, making it one of the oldest free food programs for school children.
A single afternoon lunch usually contains a cereal which is locally available, made in a way acceptable to the prevailing local customs. Vegetables cooked as curry or soups and a portion of milk is allotted for each child. The menu is occasionally varied to appeal to students.

]Japan
In Japan, 99% of elementary school students and 82% of junior high school students eat kyūshoku, or school lunch.Parents pay 250 to 300 yen per student for the cost of the ingredients, with labour costs being funded by local authorities. The tradition started in the early 20th century. After the war – which brought near-famine conditions to Japan – the provision of school lunches was re-introduced in urban areas, initially with skimmed milk powder and later flour donated by an American charity. School lunch was extended to all elementary schools in Japan in 1952 and, with the enactment of the School Lunch Law, to junior high schools in 1954.
Usually, all meals provided on a given day are identical for all pupils of a Japanese school. The menu is planned by dieticians and changes daily. The average menu has gone through a large deal of change since the basic meals of the 1950s, as Japan grew economically.
School lunches were traditionally based on bread or bread roll, bottled or cartoned milk (introduced from 1958 to replace milk powder), a dessert, and a dish which changed daily. Popular dishes from the early days included inexpensive protein sources, such as stewed bean dishes and fried white fish. Whale meat, another cheap protein, was common until the 1970s. Provisions of rice were introduced in 1976, following a surplus of (government-distributed) Japanese rice, and became increasingly frequent during the 1980s. Hamburg steak, stew and Japanese curry became staples as well. Today, school lunches are a diverse affair, including soup and side dishes. Dishes range from Asian dishes such as naengmyeon, tom yam and ma po tofu to western dishes such as spaghetti, stew and clam chowder.

Sweden
School dinner has been free in Swedish elementary and secondary schools since 1993. Normally, the lunch is prepared like a buffet, where pupils serve themselves as much as they want (mainly potatoes/rice, meat/fish and vegetables). Milk and water are usually offered as drinks.

Singapore
School meals in most primary and secondary schools, and junior colleges, are provided in each school's canteen (or tuckshop). The canteens are made up of a number of stalls selling a variety of cuisine as well as beverages. Meals in the school canteens are of a lower price compared to similar meals in public food centres in Singapore.

United Kingdom
In the UK, school meals were first introduced in the 1870s to combat the high levels of malnutrition amongst children in poor areas. In 1944 it was made compulsory for local authorities to provide school dinners, with legal nutritional requirements. Free school meals were available to children with families on very low incomes.
As a result, staple traditional "school dinner" foods became embedded in the national psyche from the 1950s onwards. "School puddings" in particular refers to desserts traditionally (historically) served with school dinners, in both state schools and private schools. Examples include tarts such as gypsy tart and Manchester tart and hot puddings such as spotted dick and treacle sponge pudding.
In the 1980s Margaret Thatcher's Conservative government ended entitlement to free meals for thousands of children, and obliged local authorities to open up provision of school meals to competitive tender. This was intended to reduce the cost of local-authority-provided school meals, but caused an enormous drop in the standard of food being fed to children. A 1999 survey by the Medical Research Council suggested that despite rationing, children in 1950 had healthier diets than their counterparts in the 1990s, with more nutrients and lower levels of fat and sugar.
This became a major topic of debate in 2004 when chef Jamie Oliver spearheaded a campaign to improve the quality of school meals. School dinners at state schools are usually made by outside caterers whose incentive is increasing their profits. Since many of the requirements for nutritional content were removed in the 1980s, there is little reason for caterers to sell anything other than cheap, profitable, low quality food, particularly deep-fried fast-food like chips.
After a television documentary was shown on Channel 4 (Jamie's School Dinners), the public showed support for the increase of funding for school meals, causing the government to create the School Food Trust. The topic became a factor in the 2005 UK general election.
United States
Some school meal programs existed in the United States at least as far back as 1899, when Principal Arthur Burch of South Division High School in Milwaukee was granted permission to open a lunch room in the building. A basement room 27 by 60 feet was selected for the purpose; a kitchen 10 by 20 feet was partitioned off in one corner; furniture, dishes, etc. were purchased (for $316.65), and Emma Stiles of Chicago was placed in charge, to purchase provisions, plan each day's menu, and to see that all lunches were paid for. The menu was posted on a blackboard in the corridor, with each dish priced at five cents. This was something in the nature of an innovation and other cities made inquiries regarding the success of the scheme. The principal advantage, according to Burch's report to the Superintendent, was derived from serving warm lunches to the students, many of whom came from a distance too great to go home every day for a warm lunch, and who did better work in the afternoons than if they had eaten a cold one.
The National School Lunch Program was created in 1946 when President Truman signed the National School Lunch Act into law. The National School Lunch Program is a federal nutrition assistance program operating in over 101,000 public and non-profit private schools and residential care institutions. Regulated and administered at the federal level by the Food and Nutrition Service of the United States Department of Agriculture (USDA), it currently provides nutritionally balanced, low-cost or free lunches to more than 30 million U.S. children each school day. In its 60-year history, the program has expanded to include the School Breakfast Program, Snack Program, Child and Adult Care Feeding Program and the Summer Food Service Program. At the State level, the National School Lunch Program is usually administered by State education agencies, who operate the program through agreements with school food authorities.


Recipient of the School Lunch Program in 1936.
Generally, public or nonprofit private schools of high school grade or under and public or nonprofit private residential child care institutions may or may not participate in the school lunch program. School districts and independent schools that choose to take part in the lunch program get cash minimal subsidies and donated commodities from the USDA for each meal they serve. In return, they must serve lunches that meet Federal requirements, and they must offer free or reduced price lunches to eligible children. School food authorities can also be reimbursed for snacks served to children through age 18 in after-school educational or enrichment programs.
School lunches must meet the applicable recommendations of the Dietary Guidelines for Americans, which state that no more than 30 percent of an individual's calories come from fat, and less than 10 percent from saturated fat. Regulations also establish a standard for school lunches to provide one-third of the Recommended Dietary Allowances of protein, Vitamin A, Vitamin C, iron, calcium, and calories. School lunches must meet Federal nutrition requirements over the course of one week's worth of lunches served, but decisions about what specific foods to serve and how they are prepared are made by local school food authorities. The 2007 School Nutrition and Dietary Assessment III (SNDA III) study based on research by the U.S. Department of Agriculture during the 2004-2005 school year found that students in more than 90% of schools surveyed had the opportunity to select lunches that were consistent with dietary standards for fat and saturated fat.
School nutrition programs are increasingly using more whole grains, fruits and vegetables, lean protein and lowfat dairy in school lunches. Efforts such as the Local School Wellness Policies required by the 2004 Child Nutrition and WIC Reauthorization Act have involved parents, students and the school community in efforts to promote healthy eating environments and increased physical activity throughout school campuses.
In 2009, the Institute of Medicine of the National Academies released School Meals: Building Blocks For Healthy Children which reviewed and provided recommendations to update the nutrition standard and the meal requirements for the National School Lunch Program and School Breakfast Program. School Meals also set standards for menu planning that focus on food groups, calories, saturated fat, and sodium and that incorporate Dietary Guidelines for Americans and the Dietary Reference Intakes.
Unhealthy school lunches are one of the contributors of malnutrition in the form of excessive consumption of unhealthy foods, however, some measures are being taken to change that. An example is the Berkeley Food System project which utilizes vegetable gardens to promote education for healthy eating. Janet Brown,who started the project explained that students are more likely to eat healthy foods such as fruits and vegetables if they are better introduced to them.

Free school meals
HealthTeacher
National School Meals Week (in the UK)
Nutrition
Personal, Social and Health Education
School Food Trust
School Health Education Study
School health services
Share Our Strength
Welfare

(source:wikipedia)

Thursday, August 12

Denial of pregnanc

Denial of pregnancy,
(also called pregnancy denial) is a rare form of denial exhibited by women to either the fact or the implications of their own pregnancy. One study found that women who denied their pregnancy represented only 0.26% of all deliveries. 


Signs and symptoms

Denial of pregnancy can be divided into three distinct types which are distinguished primarily by the severity of the denial experienced by the woman:
Affective Denial
This type of denial is characterized by a lack of the typical maternal bonding that is felt by most women during pregnancy. Although they are aware of their pregnancy, women with this disorder continue to behave as if they were not pregnant. They do not alter their clothes or lifestyle, nor do they make any preparations for the baby's arrival.
Pervasive Denial
In this form of pregnancy denial, the women suppresses all awareness of her pregnancy for extended periods of time, up to, including and even after childbirth. This psychological suppression is combined with a lack or lessening of physical symptoms of pregnancy. Women may, for example, experience little to no weight gain, or they may continue bleeding vaginally (similar to that experienced during menstruation) throughout the duration of their pregnancy.
Psychotic Denial
This is a form of denial that is so extreme as to fall under the category of delusion. While physical symptoms of pregnancy do usually occur they are misinterpreted in ways that are usually considered quite bizarre. The sensation of something growing inside the woman can be interpreted as cancer, or a blood clot, and fetal movements as the woman's organs coming loose inside her body.

(source:wikipedia)

Bishop score

Bishop score, also Bishop's score, is a pre-labour scoring system to assist in predicting whether induction of labour will be required.It has also been used to assess the odds of spontaneous preterm delivery.
Components

The total score is achieved by assessing the following five components on vaginal examination:The Bishop score grades patients who would be most likely to achieve a successful induction. The duration of labor is inversely correlated with the Bishop score; a score that exceeds 8 describes the patient most likely to achieve a successful vaginal birth. Bishop scores of less than 6 usually require that a cervical ripening method be used before other methods.
Cervical dilation
Cervical effacement
Cervical consistency
Cervical position
Fetal station
They can be remembered with the mnemonic: Call PEDS For Parturition = Cervical Position, Effacement, Dilation, Softness; Fetal Station.



Scoring

Each components is given a score of 0-2 or 0-3. The highest possible score is 13.
Bishop score
Parameter\Score0123Description
PositionPosteriorIntermediateAnterior-The position of the cervix varies between individual women. As the anatomical location of the vagina is actually downward facing, anterior and posterior locations relatively describe the upper and lower borders of the vagina. The anterior position is better aligned with the uterus, and therefore there is an increased likelihood of spontaneous delivery.
ConsistencyFirmIntermediateSoft-In primigravid women the cervix is typically tougher and resistant to stretching, much like a balloon that has not been previously inflated. Furthermore, in young women the cervix is more resilient than in older women. With subsequent vaginal deliveries the cervix becomes less rigid and allows for easier dilation at term.
Effacement0-30%31-50%51-80%>80%Effacement is a measure of stretch already present in the cervix. It is analogous to stretching a rubber band; as the rubber band is stretched further, it becomes thinner. This is affected by individual variation and previous surgery such as loop excision for cervical dysplasia or cancer.
Dilation0 cm1-2 cm3-4 cm>5 cmDilation is a measure of the diameter of the stretched cervix. It complements effacement, and is usually the most important indicator of progression through the first stage of labour.
Fetal station-3-2-1, 0+1, +2Fetal station describes the position in of the foetus' head in relation to the distance from the ischial spines, which can be palpated deep inside the posterior vagina (approximately 8-10cm) as a bony protrusion. Negative numbers indicate that the head is further inside, above the ischial spines.


Interpretation

A score of 5 or less suggests that labour is unlikely to start without induction. A score of 9 or more indicates that labour will most likely commence spontaneously.
A low Bishop's score often indicates that induction is unlikely to be successful. Some sources indicate that only a score of 8 or greater is reliably predictive of a successful induction.
Modified Bishop score

According to the Modified Bishop's pre-induction cervical scoring system, effacement has been replaced by cervical length in cm, with scores as follows- 0>3cm, 1>2cm, 2>1cm, 3>0cm.

Another modification for the Bishop's score is the modifiers. Points are added or subtracted according to special circumstances as follows:
One point is added for:
1. Existence of pre-eclampsia
2. Every previous vaginal delivery
One point is subtracted for:
1. Postdate pregnancy
2. Nulliparity (no previous vaginal deliveries)
3. PPROM (premature preterm rupture of membranes)

(source:wikipedia)

Tuesday, August 10

Drugs in pregnancy

Drugs used during pregnancy,
can have temporary or permanent effects on the fetus. Any drug that acts during embryonic or fetal development to produce a permanent alteration of form or function is known as a teratogen.

for the pregnant woman

Many physicians would prefer not to prescribe for pregnant women, the major concern being over teratogenicity of the drugs. The apprehension is not necessarily data driven and is mostly due to lack of clinical studies in pregnant women. This can result in inappropriate treatment of pregnant women and fetus. Use of drugs in pregnancy is not always wrong. For example, high fever is harmful for the fetus in the early months, thus the use of paracetamol (acetaminophen) is generally associated with lower risk than the fever itself. Similarly, diabetes mellitus during pregnancy may need intensive therapy with insulin to prevent complications to mother and baby.
Period of drug use

Pregnancy and development of fetus progresses through various changes. The period of one week from fertilisation to implantation of the fertilized egg is called preimplantation period. This is an 'all or none' period, .i.e an insult can either cause death or complete recovery. The period from the 8th day to the end of 8th week (2nd month) is the period of organogenesis during which the organs are formed in the fetus. This is the most crucial time with regard to 'structural malformations' and concern over teratogenicity of drugs. From the 3rd month week to the end of 9 months is the period of fetal maturation. Intake of drugs during this period may modify the 'function' of the fetal organs rather than causing gross structural malformations in the fetus, for example, aminoglycosides can affect the functioning of kidneys and also the hearing mechanism.
Categories of drugs

The Food and Drug Administration (FDA) has developed a rating system to provide therapeutic guidance based on potential benefits and fetal risks. Drugs have been classified into categories A, B, C, D and X based on this system of classification. Drugs like multivitamins that have demonstrated no fetal risks after controlled studies in humans are classified as Category A. On the other hand drugs like thalidomide with proven fetal risks that outweigh all benefits are classified as Category X.
Classification of a few important drugs/vaccines
Antibacterial agents
Category B : Penicillin, metronidazole, nitrofurantoin, cephalosporins, clindamycin, terbinafine, some macrolides e.g. azithromycin, erythromycin
Category C : Some aminoglycosides, chloroquine, quinolones, mebendazole, fluconazole
Category D : Tetracyclines, gentamicin, tobramycin
Cardiovascular drugs
Category B : Heparin (LMW)
Category C : Heparin (conventional), beta-blockers, (dihydropyridine) calcium antagonists, furosemide, digoxin, methyldopa
Category D : ACE inhibitors, ARBs, coumarins, thiazides, diltiazem
Central nervous system drugs
Category B : Acetaminophen, caffeine
Category C : Aspirin, clonidine, rofecoxib
Category D : Carbamezapine, valproic acid, diazepam, lithium
Vaccines
Category C : Tetanus toxoid, polio vaccine , BCG vaccine, hepatitis A vaccine, hepatitis B vaccine and rabies vaccine.

(source:wikipedia)

Immune tolerance in pregnancy

Immune tolerance in pregnancy, or gestational immune tolerance,
is the absence of a maternal immune response against the fetus and placenta, which thus may be viewed as unusually successful allografts, since they genetically differ from the mother.In the same way, many cases of spontaneous abortion may be described in the same way as maternal transplant rejection.


Mechanisms

Placental mechanisms


The placenta functions as an immunological barrier between the mother and the fetus.
The placenta functions as an immunological barrier between the mother and the fetus, creating an immunologically privileged site. For this purpose, it uses several mechanisms:
It secretes Neurokinin B containing phosphocholine molecules. This is the same mechanism used by parasitic nematodes to avoid detection by the immune system of their host.
Also, there is presence of small lymphocytic suppressor cells in the fetus that inhibit maternal cytotoxic T cells by inhibiting the response to interleukin 2.
The placental trophoblast cells do not express the classical MHC class I isotypes HLA-A and HLA-B, unlike most other cells in the body, and this absence is assumed to prevent destruction by maternal cytotoxic T cells, which otherwise would recognize the fetal HLA-A and HLA-B molecules as foreign. On the other hand, they do express the atypical MHC class I isotypes HLA-E and HLA-G, which is assumed to prevent destruction by maternal NK cells, which otherwise destruct cells that do not express any MHC class I.However, trophoblast cells do express the rather typical HLA-C.
It forms a syncytium without any extracellular spaces between cells in order to limit the exchange of migratory immune cells between the developing embryo and the body of the mother (something an epithelium will not do sufficiently, as certain blood cells are specialized to be able to insert themselves between adjacent epithelial cells). The fusion of the cells is apparently caused by viral fusion proteins from endosymbiotic endogenous retrovirus (ERV). [4] An immunoevasive action was the initial normal behavior of the viral protein, in order to avail for the virus to spread to other cells by simply merging them with the infected one. It is believed that the ancestors of modern viviparous mammals evolved after an infection by this virus, enabling the fetus to better resist the immune system of the mother.
Still, the placenta does allow maternal IgG antibodies to pass from to the fetus to protect it against infections. However, these antibodies do not target fetal cells, unless any fetal material has escaped across the placenta where it can come in contact with maternal B cells and make those B cells start to produce antibodies against fetal targets. The mother does produce antibodies against foreign ABO blood types, where the fetal blood cells are possible targets, but these preformed antibodies are of the IgM type,and do not cross the placenta.
Other mechanisms
Still, the placental barrier is not the sole means to evade the immune system, as foreign fetal cells also persist in the maternal circulation, on the other side of the placental barrier.
In any case, the placenta does not block maternal IgG antibodies, which thereby may pass through the human placenta, providing immune protection to the fetus against infectious diseases.
One model for the induction of tolerance during the very early stages of pregnancy is the Eutherian Fetoembryonic Defense System (eu-FEDS) hypothesis. The basic premise of the eu-FEDS hypothesis is that both soluble and cell surface associated glycoproteins, present in the reproductive system and expressed on gametes, suppress any potential immune responses, and inhibit rejection of the fetus . The eu-FEDS model further suggests that specific carbohydrate sequences (oligosaccharides) are covalently linked to these immunosuppressive glycoproteins and act as “functional groups” that suppress the immune response. The major uterine and fetal glycoproteins that are associated with the eu-FEDS model in the human include alpha-fetoprotein, CA125, and glycodelin-A (also known as placental protein 14 (PP14)).
Regulatory T cells also likely play a role.[9].
Also, a shift from cell-mediated immunity toward humoral immunity is believed to occur.
Insufficient tolerance

Many cases of spontaneous abortion may be described in the same way as maternal transplant rejection. Other examples of insufficient immune tolerance in pregnancy are Rh disease and pre-eclampsia:
Rh disease is caused by the mother producing antibodies (including IgG antibodies) against the Rhesus D antigen on her baby's red blood cells. It occurs if the mother is Rh negative and the baby is Rh positive, and a small amount of Rh positive blood from any previous pregnancy has entered the mother's circulation to make her produce IgG antibodies against the Rhesus D antigen. Maternal IgG is able to pass through the placenta into the fetus and if the level of it is sufficient, it will cause destruction of Rhesus D positive fetal red blood cells leading to development Rh disease. Generally Rhesus disease becomes worse with each additional Rhesus incompatible pregnancy.
One cause of pre-eclampsia is an abnormal immune response towards the placenta. There is substantial evidence for exposure to partner's semen as prevention for pre-eclampsia, largely due to the absorption of several immune modulating factors present in seminal fluid.
Increased infectious susceptibility

The immunologic changes in pregnancy alters the susceptibility to and severity of infectious diseases. For example, pregnancy may increase susceptibility to toxoplasmosis and listeriosis and may increase severity of illness and increase mortality rates from influenza and varicella. 
Xenopregnancy

If the mechanisms of rejection-immunity of the fetus could be elucidated, it could avail for xenopregnancy, having, for example pigs carry human fetuses to term as an alternative to a human surrogate mother, providing a sober, drug-free and nonsmoking carrier.

(source:wikipidia)

Nutrition and pregnancy

Nutrition and pregnancy,
refers to the nutrient intake, and dietary planning that is undertaken before, during and after pregnancy. All dietary advice relating to pregnancy-related nutrition is noted by Mary E. Barasi as one of the major factors in determining the future well-being of a child conceived, some factors of a diet are even noted to reduce childhood morbidity and mortality due to helping the supply of nutrients to the mother. 
In a precursory study into the link between nutrition and pregnancy in 1950 women who consumed minimal amounts over the eight week period had a higher mortality or disorder rate concerning their offspring than women who ate regularly, because children born to well-fed mothers had less restriction within the womb. 
Not only have physical disorders been linked with poor nutrition before and during pregnancy, but neurological disorders and handicaps are a risk that is run by mothers who are malnourished, a condition which can also lead to the child becoming more susceptible to later degenerative disease(s). 
The following sections refer to the pertinence of nutrition throughout pregnancy, and are thoroughly researched enough to be usable for mothers or couples planning on conceiving.

Nutrition before pregnancy

Potentially harmful pre-pregnancy determinants
It is known that good nutrition before pregnancy is important because of the amount of "resources" childbirth requires. The process of pre-pregnancy nutrition is a process of "building up" the immune system in preparation of pregnancy, and is known as being one of the major factors in determining the success rate of conceiving healthy children.
As with most situations, the most important factor in pre-pregnancy nutrition is ensuring that the mother is healthy and without any major factors which could worsen the chances of conceiving, factors such as anorexia or bulimia are thought to be direct links with infertility; the minimum body mass index for conceiving mothers being 20.8.
This is also seen to be true with obese women with a BMI above 30 which is a direct result of decrementing amounts of insulin activity and sex hormones may reduce the viability of the ovum.
The ideal range of weight for women wishing to conceive children is thought to be optimal at body mass indexes between 20 and 26. If this, again, is used in conjunction with good nutrition and diet before pregnancy in terms of a normal balanced diet, then reserves of micronutrients, providing materials for pregnancy, would also be maximised.
For more information on how BMI is calculated, please refer to the body mass index article.
Beneficial pre-pregnancy nutrients
As with most diets, there are chances of over-supplementing, however, as general advice, both state and medical recommendations are that mothers follow instructions listed on particular vitamin packaging as to the correct or recommended daily allowance (RDA).
Magnesium and zinc supplementation for the binding of hormones at their receptor sites.
Folic acid supplementation, or dietary requirement of foods containing it for the regular growth of the follicle.
Regular Vitamin D supplementation decreases the chances of deficiencies in adolescence. More importantly, it is known to reduce the likelihood of rickets with pelvic malformations which make normal delivery impossible.
Regular Vitamin B12 supplementation, again is known to reduce the chances of infertility and ill health.
Nutrition during pregnancy

The conception and the subsequent weeks afterwards is the time when it is at its most vulnerable, as it is the time when the organs and systems develop within. The energy used to create these systems comes from the energy and nutrients in the mother's circulation, and around the lining of the womb, such is the reason why correct nutrient intake during pregnancy is so important.
During the early stages of pregnancy, the placenta is not formed yet, so there is no mechanism to protect the embryo from the deficiencies which may be inherent in the mother's circulation, so it is critical that the correct amount of nutrients and energy are consumed.
Potentially harmful determinants during pregnancy
Intake of retinol, in extreme cases, has been linked to birth defects and abnormalities. However, regular intake of retinol is not seen as dangerous. It is noted that a 100 g serving of liver may contain a large amount of retinol, so it is best that it is not eaten daily during pregnancy, something which is also the same with alcohol intake in binge drinking.
Excessive amounts of alcohol have been proven to cause Fetal alcohol syndrome. The World Health Organization recommends that alcohol should be avoided entirely during pregnancy, given the relatively unknown effects of even small amounts of alcohol during pregnancy.
Maternal obesity has a significant impact on maternal metabolism and offspring development. Insulin resistance, glucose homeostasis, fat oxidation and amino acid synthesis are all disrupted by maternal obesity and contribute to adverse outcomes. Modification of lifestyle is an effective intervention strategy for improvement of maternal metabolism and the prevention of adverse outcomes.


Recommended nutrients during pregnancy

NutrientRecommendation (Extra = Above RDA)Maximum/Total amount
EnergyIncrease by 200 kcal (840 kJ) per day in last trimester only.RDA
ProteinsExtra 6 g per day51 g per day
ThiaminIncrease in line with energy; increase by 0.1 mg per day0.9 mg per day
RiboflavinNeeded for tissue growth; extra 0.3 mg per day1.4 mg per day
NiacinRegular supplementation/diet of substance. No increase required.RDA
FolateMaintain plasma levels; extra 100 µg per day300 µg per day
Vitamin CReplenish drained maternal stores; extra 120 mg per day50 mg per day
Vitamin DReplenish plasma levels of vitamin 10 µg per day.RDA
CalciumNeeds no increaseRDA
IronExtra 3 mg per day neededRDA
Magnesium, zinc, and copperNormal supplementation or consumption.RDA
IodineExtra 100 µg per day.250 µg per day


Folate
Deficiencies in folic acid may cause neural tube defects; women who had 4 mg of folic acid in their systems due to supplementing 3 months before childbirth significantly reduced the risk of NTD within the fetus. This is now advocated by the UK department of health, recommending 400 µg per day of folic acid.
Folate and Acute Lymphoblastic Leukemia
Along with neural tube development, folate affects DNA synthesis in multiple ways. As Ball explains, folate is involved in the construction of purines and pyrimidines, the building blocks of nucleic acids. Folate is also necessary to make s-adenosylmethionine (SAM), which acts as a methyl donor in the synthesis of DNA. Because of its role in these important mechanisms, fetal DNA would be significantly altered if a maternal folate deficiency is present. One possible outcome is DNA mutation, which could prevent normal gene expression. For example, a tumor-suppressing gene might be turned off, altering normal immune function in preventing cancer growth. Thompson et al.  examined the relationship between maternal supplementation of folate and iron during pregnancy and incidences of acute lymphoblastic leukemia (ALL) in their children. Increased rates of ALL were found in children whose mothers did not take iron and folate supplements. Iron alone did not seem to reduce the risk of developing ALL, however iron in combination with folate was shown to have a protective effect in decreasing the risk for ALL. Thompson and his associates (2001), concluded that maternal folate supplementation throughout pregnancy plays an important role in reducing the risk for childhood ALL 
Nutrition after pregnancy

Proper nutrition is important after delivery to help the mother recover, and to provide enough food energy and nutrients for a woman to breastfeed her child. Women having serum ferritin <= 70 µg/L may need iron supplements to prevent iron deficiency anaemia during pregnancy and postpartum.

(source:wikipedia)