While a healthy diet should always be followed, it is particularly vital to stick to dietary recommendations and restrictions during the period of pregnancy.

To-be-mothers should seek advice from their doctors on what they should be eating more, what they should reduce, and what they should stop eating completely. In most cases, experts have stated that the following are best avoided:

1. Raw meat

Toxoplasmosis is a foodborne illness caused by a parasite (Toxoplasma gondii) which can be found in raw and undercooked meat. Acquiring the infection during pregnancy can be dangerous as it can raise the risk of hearing loss, brain problems, and blindness in the baby.

Thorough cooking should be ensured with meat such as pork, lamb, sausages, etc. as well as poultry. Also, avoid exposure from knives, utensils or kitchen surfaces that may have come into contact with raw meat.

2. Soft cheeses

Cheeses made from unpasteurized milk can carry the risk of listeriosis i.e. being infected by a type of bacteria known as listeria. It can increase the risk of infection for the newborn baby, miscarriage, premature delivery, or stillbirth.

The Centers for Disease Control and Prevention (CDC) recommends skipping out on soft cheeses such as feta, brie, Camembert, and blue-veined cheeses. Hispanic cheeses such as queso fresco and queso blanco should also be avoided due to a high risk of contamination.

3. Fish with mercury

Consuming fish high in mercury is not recommended for women who are pregnant or breastfeeding as mercury exposure can affect brain development in the child. Types that should be avoided include tuna, Gulf tilefish, king mackerel, marlin, orange roughy, shark, and swordfish.

However, varieties of fish with low levels of mercury can be consumed as they provide pregnant women with health benefits. "The best option for people in the at-risk groups is to stick to the fish on Consumer Reports' low- and lowest-mercury fish lists," said Jean Halloran, director of food policy initiatives for Consumers Union.

4. Certain supplements

It is not advisable to take high-dose multivitamin supplements or fish liver oil supplements during pregnancy. Vitamin A, linked to birth defects when consumed in high quantities, should also be avoided unless specifically recommended by the doctor.

"For most women who are planning to become pregnant or who are pregnant, complex multivitamin and mineral preparations promoted for use during pregnancy are unlikely to be needed and are an unnecessary expense," stated one study published in 2016.

5. Excess caffeine

Experts recommend that caffeine consumption remains under 200 milligrams over the course of pregnancy. High levels could potentially cause the baby to have a low birthweight while animal studies have found decreased fertility and an increased risk of miscarriage.

"Caffeine in pregnancy can be an issue if large amounts are consumed," said Dr. Michele Hakakha, a board-certified OB-GYN based in Beverly Hills, California. "We know from many of our studies that caffeine crosses the placenta, and a baby's developing metabolism can't quite handle the caffeine jolt."