Nutritional Care in Pregnancy
expected date of delivery (EDD) is 40 weeks counting from the first day
of the last menstrual period (LMP), and birth usually occurs between 37
and 42 weeks. Though pregnancy begins at implantation, it is more
convenient to date from the first day of a woman's last menstrual
period, or from the date of conception if known. Starting from one of
these dates, the expected date of delivery can be calculated using the
Naegele's rule for estimating date of delivery. A more sophisticated
algorithm takes into account other variables, such as whether this is
the first or subsequent child (i.e., pregnant woman is a primip or a
multip, respectively), ethnicity, parental age, length of menstrual
cycle, and menstrual regularity.
Physiology of Pregnancy
Diagnosis of Pregnancy
Duration of Pregnancy
Nutritional Care in
A balanced, nutritious diet is an important aspect of a healthy
pregnancy. Eating a healthy diet, balancing carbohydrates, fat, and
proteins, and eating a variety of fruits and vegetables, usually ensures
good nutrition. Those whose diets are affected by health issues,
religious requirements, or ethical beliefs may choose to consult a
health professional for specific advice.
Adequate periconceptional folic acid (also called folate or Vitamin B9)
intake has been proven to limit fetal neural tube defects, preventing
spina bifida, a very serious birth defect. The neural tube develops
during the first 28 days of pregnancy, explaining the necessity to
guarantee adequate periconceptional folate intake. Folates (from folia,
leaf) are abundant in spinach (fresh, frozen, or canned), and are found
in green leafy vegetables e.g. salads, beets, broccoli, asparagus,
citrus fruits and melons, chickpeas (i.e. in the form of hummus or
falafel), and eggs. In the United States and Canada, most wheat products
(flour, noodles) are fortified with folic acid.
DHA omega-3 is a major structural fatty acid in the brain and retina,
and is naturally found in breast milk. It is important for the woman to
consume adequate amounts of DHA during pregnancy and while nursing to
support her well-being and the health of her infant. Developing infants
cannot produce DHA efficiently, and must receive this vital nutrient
from the woman through the placenta during pregnancy and in breast milk
Several micronutrients are important for the health of the developing
fetus, especially in areas of the world where insufficient nutrition is
prevalent. In developed areas, such as Western Europe and the United
States, certain nutrients such as Vitamin D and calcium, required for
bone development, may require supplementation. A 2011 study examined
cord blood of healthy neonates and found that low levels of vitamin D
are associated with increased risk of lower respiratory tract infection
the first year of life.
Dangerous bacteria or parasites may contaminate foods, particularly
Listeria and toxoplasma, toxoplasmosis agent. Careful washing of fruits
and raw vegetables may remove these pathogens, as may thoroughly cooking
leftovers, meat, or processed meat. Soft cheeses may contain Listeria;
if milk is raw, the risk may increase. Pregnant women are also more
prone to Salmonella infections from eggs and poultry, which should be
thoroughly cooked. Practicing good hygiene in the kitchen can reduce
Caloric intake must be increased to ensure proper development of the
fetus. The amount of weight gained during a single pregnancy varies
among women. The Institute of Medicine recommends an overall pregnancy
weight gain for women starting pregnancy at a normal weight, with a body
mass index of 18.5-24.9, of 25-35 pounds (11.4-15.9 kg). Women who are
underweight, with a BMI of less than 18.5, may need to gain between
28-40 lbs. Overweight women are advised to gain between 15-25 lbs,
whereas an obese woman may expect to gain between 11-20 lbs. Doctors and
dietitians may make different, or more individualized, recommendations
for specific patients, based on factors including low maternal age,
nutritional status, fetal development, and morbid obesity.
During pregnancy, insufficient or excessive weight gain can compromise
the health of the mother and fetus. All women are encouraged to choose a
healthy diet regardless of pre-pregnancy weight. Exercise during
pregnancy, such as walking and swimming, is recommended for healthy
pregnancies. Exercise has notable health benefits for both mother and
baby, including preventing excessive weight gain.
EXPOSURE TO TOXINS
Various toxins pose a significant hazard to fetuses during development:
||Alcohol ingestion during
pregnancy may cause fetal alcohol syndrome, a permanent and often
devastating birth-defect syndrome. A number of studies have shown
that light to moderate drinking during pregnancy might not pose a
risk to the fetus, although no amount of alcohol during pregnancy
can be guaranteed to be absolutely safe.
||Numerous studies show that
children exposed to prenatal cigarette smoke may experience a wide
range of behavioral, neurological, and physical difficulties.
||Elemental mercury and
methylmercury are two forms of mercury that may pose risks in
pregnancy. Methylmercury, a worldwide contaminant of seafood and
freshwater fish, is known to produce adverse nervous system effects,
especially during brain development. Eating fish is the main source
of mercury exposure in humans and some fish may contain enough
mercury to harm an unborn baby's developing nervous system,
sometimes leading to learning disabilities. Mercury is present in
many types of fish, but it is mostly found in certain large fish.
The United States Food and Drug Administration and the Environmental
Protection Agency advise pregnant women not to eat swordfish, shark,
king mackerel and tilefish and limit consumption of albacore tuna to
6 ounces or less a week.
||The Center for Children's Environmental
Health reports studies that demonstrate that exposure to air
pollution during pregnancy is related to adverse birth outcomes
including low birth weight, premature delivery, and heart
malformations. Cord blood of exposed babies shows DNA damage that
has been linked to cancer. Follow-up studies show a higher level of
developmental delays at age three, lower scores on IQ tests and
increased behavioral problems at ages six and eight.
||According to the U.S. Centers for Disease
Control, the developing nervous system of the fetus is particularly
vulnerable to lead toxicity. Neurological toxicity is observed in
children of exposed women as a result of the ability of lead to
cross the placental barrier and to cause neurological impairment in
the fetus. A special concern for pregnant women is that some of the
bone lead accumulation is released into the blood during pregnancy.
Several studies have provided evidence that even low maternal
exposures to lead produce intellectual and behavioral deficits in
||A 2006 study found that children who were
exposed prenatally to the insecticide chlorpyrifos had significantly
poorer mental and motor development by three years of age and
increased risk for behavior problems. A 2007 study using a mouse
model suggested that exposure to polycyclic aromatic hydrocarbons
prior to conceiving and when lactating reduces the number of eggs in
the ovaries of female offspring by two-thirds. A 2009 study of
pregnant women exposed to tetrachloroethylene in drinking water
found an increased risk of oral clefts and neural tube defects in
their children. A 2009 study found that prenatal exposure to
phthalates, the chemical compounds used as plasticizers in a wide
variety of personal care products, children's toys, and medical
devices, may be an environmental risk factor for low birth weight in
infants." A 2010 study found that prenatal exposure to flame
retardant compounds called polybrominated diphenyl ethers is
associated with adverse neurodevelopmental effects in young
NUTRITION AND PREGNANCY refers to the nutrient intake, and
dietary planning that is undertaken before, during and after pregnancy.
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
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.
|| Omega-3 fatty acids can increase blood flow to
reproductive organs and may help regulate reproductive hormones.
Consumption is also known to help prevent premature delivery and low
birth weight. The best dietary source of omega-3 fatty acids is oily
fish. Some other omega-3 fatty acids not found in fish can be found
in foods such as flaxseeds, walnuts, pumpkin seeds, and enriched