Table of ContentsView AllTable of ContentsCausesSymptomsOther Types of Cramps
Table of ContentsView All
View All
Table of Contents
Causes
Symptoms
Other Types of Cramps
Implantation cramps happen sometimes when a fertilized egg implants or attaches itself into theuterinelining—in other words, when you first get pregnant. Some people may get these cramps while others may not feel anything at all.
Often, implantation cramps feel similar tomenstrualcramps, but they tend to be milder. They have absolutely no impact on your pregnancy or the health of your growingfetus.
This article describes the symptoms and causes of implantation cramps, including how they feel and how they differ from other types of cramps that can occur during pregnancy.
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Causes of Implantation Cramps
It may be easier to understand the cause of implantation cramps if you understand the stages of implantation.
For implantation to occur, hormones calledprostaglandinsare released, which cause the blastocyst to shed its outer shell (a process known as “hatching”). This occurs one to three days after the blastocyst enters the uterus. The blastocyst then burrows into the outer layer of the endometrium.
Prostaglandins are hormones associated with pain andinflammation. It is these hormones that trigger muscle contractions in the uterus, causing cramping.
By contrast, implantation bleeding occurs when the blastocyst attaches to the wall of the uterus and breaks down some of the blood vessels within the endometrium.
Cramps But No Period: Getting to the Cause
Symptoms of Implantation Cramps
Everyone who gets pregnant experiencesimplantationdifferently. Many notice nothing at all, while others may experience cramps, light bleeding, or both.
Common signs of implantation include:
The cramping can come and go but usually resolve within a couple of days.
Where the Pain Is FeltMost people experience implantation cramps in the lower abdomen or lower back. Depending on where the egg implants, the cramps may be felt on one side of the body, such as the lower left or lower right side of the abdomen.
Where the Pain Is Felt
Most people experience implantation cramps in the lower abdomen or lower back. Depending on where the egg implants, the cramps may be felt on one side of the body, such as the lower left or lower right side of the abdomen.
Causes of Cramps During Pregnancy
Implantation Cramps vs. Other Cramps
Implantation isn’t the only thing that can cause cramping during pregnancy. Several situations can mimic implantation cramps, some of which may be serious. It is important, therefore, to contact yourobstetricianif you ever have cramps that seem odd or unusual.
Menstrual Cramps
Since implantation often occurs around the same time as your period, it is easy to confuse implantation cramps for menstrual cramps, and vice versa.
Menstrual cramps (calleddysmenorrhea) can occur in the days leading up to your period. The pain often starts one to three days before your period, peaks 24 hours after your period begins, and subsides within two to three days.
Unlike implantation cramps, the pain from menstrual cramps can be continuous rather than intermittent. It is also generally stronger, often radiating pain to the lower back and thighs. Moreover, there would be the usual amount of menstrual bleeding rather than light spotting.
Ovulation Cramps vs. Implantation Cramps
Some people experience cramps when they ovulate. This type of cramping, also known asmittelschmerz, is discernible from implantation cramping in that it occurs earlier, usually a couple of weeks before implantation. (However, if you haveirregular periods, telling them apart can be difficult.)
Mittelschmerz (derived from the German word for “middle pain”) is similar to implantation cramping in that the main symptoms are mild abdominal pain and spotting. The main difference (aside from the timing) is that ovulation cramps are more one-sided.
Ovulation pain is common, affecting more than 40% of menstruating people.
Early Miscarriage
A very earlymiscarriage, also known as achemical pregnancy, is one that occurs before the fifth week of pregnancy. At this stage, most people don’t know they are pregnant or that they’ve experienced a pregnancy loss. In cases like these, the bleeding is often mistaken for a regular period.
Even so, chemical pregnancies have distinctive features, including:
How Common Is Early Miscarriage?Researchers believe that chemical pregnancies account for between 8% and 33% of all pregnancies.
How Common Is Early Miscarriage?
Researchers believe that chemical pregnancies account for between 8% and 33% of all pregnancies.
Ectopic Pregnancy
Anectopic pregnancyis one that occurs outside of the uterus, usually in thefallopian tube. An ectopic pregnancy is a medical emergency. This is because the growing embryo can cause the fallopian tube to spontaneously rupture, leading to life-threatening blood loss.
The early signs of an ectopic pregnancy are similar to those of implantation, including cramping and bleeding. Even so, the pain and bleeding tend to be longer-lasting and worsen over time.
If your fallopian tube bursts, you can experience sudden and severe symptoms, like:
Risk of DeathCall 911 or have someone rush you to the nearest emergency room if you have signs of an ectopic pregnancy. Bleeding from ectopic pregnancy accounts for 10% of all pregnancy-related deaths and is the leading cause of first-trimester maternal deaths.
Risk of Death
Call 911 or have someone rush you to the nearest emergency room if you have signs of an ectopic pregnancy. Bleeding from ectopic pregnancy accounts for 10% of all pregnancy-related deaths and is the leading cause of first-trimester maternal deaths.
10 Leading Causes of Infant Death
Summary
Some people experience mild cramping, known as implantation cramps, when they first become pregnant. This is caused when a fertilized egg embeds itself into the wall of the uterus. Mild bleeding, known as implantation, may also occur. These symptoms are generally short-lasting and resolve within two to three days.
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Kim SM, Kim JS.A review of mechanisms of implantation.Dev Reprod.2017 Dec;21(4):351–9. doi:10.12717/DR.2017.21.4.351Su R, Fazleabas A.Implantation and establishment of pregnancy in human and nonhuman primates. In:Regulation of Implantation and Establishment of Pregnancy in Mammals. New York, NY: Springer Publishing; 2015.MedlinePlus.Fetal development.American College of Obstetricians and Gynecologists.Dysmenorrhea: Painful periods.National Health Service (UK).Ovulation pain.Department of Health, State Government of Victoria.Ovulation pain.Annan JJ, Gudi A, Bhide P, Shah A, Homburg R.Biochemical pregnancy during assisted conception: A little bit pregnant.J Clin Med Res. 2013;5(4):269-74. doi:10.4021/jocmr1008wLee H, Lee H, Yang K, Cha S, Ahn H, Kim Y.Etiological evaluation of repeated biochemical pregnancy in infertile couples who have undergone in vitro fertilization.Obstet Gynecol Sci. 2017;60(6):565. doi:10.5468/ogs.2017.60.6.565American College of Obstetricians and Gynecologists.Practice bulletin: Tubal ectopic pregnancy.Stremick JK, Couperus K, Ashworth SW.Ruptured tubal ectopic pregnancy at fifteen weeks gestational age.Clin Pract Cases Emerg Med. 2019;3(1):62-4. doi:10.5811/cpcem.2019.1.40860
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Kim SM, Kim JS.A review of mechanisms of implantation.Dev Reprod.2017 Dec;21(4):351–9. doi:10.12717/DR.2017.21.4.351Su R, Fazleabas A.Implantation and establishment of pregnancy in human and nonhuman primates. In:Regulation of Implantation and Establishment of Pregnancy in Mammals. New York, NY: Springer Publishing; 2015.MedlinePlus.Fetal development.American College of Obstetricians and Gynecologists.Dysmenorrhea: Painful periods.National Health Service (UK).Ovulation pain.Department of Health, State Government of Victoria.Ovulation pain.Annan JJ, Gudi A, Bhide P, Shah A, Homburg R.Biochemical pregnancy during assisted conception: A little bit pregnant.J Clin Med Res. 2013;5(4):269-74. doi:10.4021/jocmr1008wLee H, Lee H, Yang K, Cha S, Ahn H, Kim Y.Etiological evaluation of repeated biochemical pregnancy in infertile couples who have undergone in vitro fertilization.Obstet Gynecol Sci. 2017;60(6):565. doi:10.5468/ogs.2017.60.6.565American College of Obstetricians and Gynecologists.Practice bulletin: Tubal ectopic pregnancy.Stremick JK, Couperus K, Ashworth SW.Ruptured tubal ectopic pregnancy at fifteen weeks gestational age.Clin Pract Cases Emerg Med. 2019;3(1):62-4. doi:10.5811/cpcem.2019.1.40860
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Kim SM, Kim JS.A review of mechanisms of implantation.Dev Reprod.2017 Dec;21(4):351–9. doi:10.12717/DR.2017.21.4.351Su R, Fazleabas A.Implantation and establishment of pregnancy in human and nonhuman primates. In:Regulation of Implantation and Establishment of Pregnancy in Mammals. New York, NY: Springer Publishing; 2015.MedlinePlus.Fetal development.American College of Obstetricians and Gynecologists.Dysmenorrhea: Painful periods.National Health Service (UK).Ovulation pain.Department of Health, State Government of Victoria.Ovulation pain.Annan JJ, Gudi A, Bhide P, Shah A, Homburg R.Biochemical pregnancy during assisted conception: A little bit pregnant.J Clin Med Res. 2013;5(4):269-74. doi:10.4021/jocmr1008wLee H, Lee H, Yang K, Cha S, Ahn H, Kim Y.Etiological evaluation of repeated biochemical pregnancy in infertile couples who have undergone in vitro fertilization.Obstet Gynecol Sci. 2017;60(6):565. doi:10.5468/ogs.2017.60.6.565American College of Obstetricians and Gynecologists.Practice bulletin: Tubal ectopic pregnancy.Stremick JK, Couperus K, Ashworth SW.Ruptured tubal ectopic pregnancy at fifteen weeks gestational age.Clin Pract Cases Emerg Med. 2019;3(1):62-4. doi:10.5811/cpcem.2019.1.40860
Kim SM, Kim JS.A review of mechanisms of implantation.Dev Reprod.2017 Dec;21(4):351–9. doi:10.12717/DR.2017.21.4.351
Su R, Fazleabas A.Implantation and establishment of pregnancy in human and nonhuman primates. In:Regulation of Implantation and Establishment of Pregnancy in Mammals. New York, NY: Springer Publishing; 2015.
MedlinePlus.Fetal development.
American College of Obstetricians and Gynecologists.Dysmenorrhea: Painful periods.
National Health Service (UK).Ovulation pain.
Department of Health, State Government of Victoria.Ovulation pain.
Annan JJ, Gudi A, Bhide P, Shah A, Homburg R.Biochemical pregnancy during assisted conception: A little bit pregnant.J Clin Med Res. 2013;5(4):269-74. doi:10.4021/jocmr1008w
Lee H, Lee H, Yang K, Cha S, Ahn H, Kim Y.Etiological evaluation of repeated biochemical pregnancy in infertile couples who have undergone in vitro fertilization.Obstet Gynecol Sci. 2017;60(6):565. doi:10.5468/ogs.2017.60.6.565
American College of Obstetricians and Gynecologists.Practice bulletin: Tubal ectopic pregnancy.
Stremick JK, Couperus K, Ashworth SW.Ruptured tubal ectopic pregnancy at fifteen weeks gestational age.Clin Pract Cases Emerg Med. 2019;3(1):62-4. doi:10.5811/cpcem.2019.1.40860
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