Spices

Allspice (Pimenta)

Not recommended in medicinal quantities.
Safe

Anise (Aniseed)

Can have an adverse reaction due to 'oestrogen activity', and if you have been recommended against birth control pills by a doctor you should avoid this.
Source
Careful
Safe
Safe

Bumbu

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe

Caraway

In large quantities it can cause uterine contractions.

Source
Careful
Safe

Cayenne Pepper

If you suffer from acute heartburn brought on by pregnancy cayenne may make it worse.
Source
Safe
Safe

Cinnamon

Can lead to uterine contractions in high quantities (in food should be fine).
Source
Safe

Clove

Can lead to uterine contractions in concentrated doses.
Source
Safe
Source
Unsafe

Cumin

Reported to lead to uterine contractions in high doses.
Source
Safe

Curry Powder

This is a spice blend which contains a variety of other ingredients in small quantities. All varieties of curry powder (Masala, Madras, Balti, mild, hot) should be safe, but double check the ingredients if you're worried.
Safe

Fenugreek

Has been used to induce labour and is considered to be an emmenagogue.

Source
Careful

Filé Powder

Filé Powder (also known as Filé Gumbo) is made from sassafras leaves, which are toxic in medicinal quantities.
Safe

Five Spice

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe

Garam Masala

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe
Source
Unsafe

Grains Of Selim (Kimba Pepper, Djar)

Grains Of Selim, a key ingredient in Touba Coffee, are traditionally used as a contraceptive in seed form.
Safe

Guarana

Guarana is usually added to natural drinks and contains high levels of caffeine.
Source
Careful

Jerk Seasoning

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be perfectly fine, but double check each one if you're worried.
Safe

Lemon Pepper

Lemon pepper is actually a mixture of lemon zest and black peppercorns. Both are safe.
Safe

Mace

Nutmeg and mace were thought to have abortifacient qualities, but it is safe in culinary quantities.
Source
Careful

Mulling Spices

This mixture is used in mulled wine, and it contains a variety of other ingredients in small quantities. Most should be safe, but double check if you're worried.
Safe

Nigella (Black Caraway, Black Onion Seeds)

Extremely high quantities can reportedly have adverse affects.
Source
Safe
Source
Safe

Nutmeg

Nutmeg was thought to have abortifacient qualities, but it is safe in culinary quantities.
Source
Careful

Old Bay Seasoning

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be perfectly fine, but double check each one if you're worried.
Safe

Panch Phoran

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe

Paprika

Hot, sweet, and smoked paprikas are all fine.
Safe

Peppercorns

All varieties of peppercorn should be safe when used in food. High quantities are not recommended due to reported emmenagogue qualities.
Source
Safe

Ras El Hanout

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe

Saffron

In high doses it can act as a uterine stimulant.
Source
Safe
Safe

Shichimi

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe
Safe

Star Anise

Large quantities are not recommended, but in food or drink (such as chai) it is safe.
Safe
Safe

Turmeric

Turmeric supplements are not recommended.
Source
Safe
Safe

Za'atar

This is a spice blend which contains a variety of other ingredients in small quantities. Most should be safe, but double check the ingredients.
Safe