Abdominal pain during early pregnancy is a common symptom that plagues many pregnant women. Pregnant women are already prone to anxiety, and this discomfort can easily cause them to associate it with what they normally “see and hear”, thus increasing their anxiety. Let’s analyze the causes of this early pregnancy abdominal pain. The actual fact is that you can find a lot of people who are not able to get the best out of your own home. The follicles in women develop and rupture in the ovaries. After the follicles rupture, the eggs are expelled from the ovaries and the follicular shells are retained in the ovaries to form the corpus luteum, which then produces estrogen and progesterone to act on the endometrium to prepare the fertilized egg for implantation. If a fertilized egg is not formed within 7 days after ovulation, the corpus luteum begins to atrophy and menstruation follows 7 days thereafter. If a fertilized egg is formed within 7 days after ovulation, HCG produced by the trophoblast surrounding the fertilized egg will stimulate the corpus luteum to maintain its function. The corpus luteum continues to exist and grows in size in response to HCG stimulation in order to produce sufficient estrogen and progesterone. The corpus luteum is located in the ovary, and because the enlarged corpus luteum stimulates the ovary and causes distension and pain in the ovary, this early pregnancy abdominal pain would be more appropriately called “ovarian pain” and “corpus luteum pain”. Luteal pain is a common cause of abdominal pain within 6 weeks of pregnancy. Because the ovaries are located on both sides of the abdomen and the corpus luteum is located in one ovary, this abdominal pain is often manifested as distension and pain in one side of the abdomen. Differentiation between abdominal pain in early pregnancy and abdominal pain in ectopic pregnancy In some medical sources, “abdominal pain in ectopic pregnancy” is also described as painful distention in one side of the lower abdomen. This is very similar to the description of “luteal pain”. However, the time of occurrence is different. Ectopic pregnancy is asymptomatic in its early stages, and if the abdominal pain is produced directly by the ectopic sac, it often does not occur until it is about to rupture, whereas rupture of an ectopic pregnancy is seen as early as after the 7th week of pregnancy and more often after the 8th week of pregnancy. This means that severe abdominal pain should be considered in relation to ectopic pregnancy only when it occurs after the 7th week of pregnancy. Today, with the development of medicine, the first ultrasound is scheduled between 47 and 55 days of gestation to detect ectopic pregnancy when it is relatively safe and to clarify the presence of a fetal heartbeat for early detection of embryonic abortion. The doubling of HCG between 30 and 42 days of pregnancy can help to detect ectopic pregnancy and determine the development of the embryo without the fear of abdominal pain during early pregnancy due to ectopic pregnancy. The textbook states that “ectopic pregnancy is diagnosed when no intrauterine gestational sac is found on vaginal ultrasound at HCG > 2000 IU/L”. In the majority of cases, ectopic pregnancy is not visible on ultrasound, and the presence of a gestational sac in the uterus is called “except for ectopic pregnancy”, while ectopic pregnancy should be considered when no gestational sac is seen in the uterus. When the gestational sac is visible in the uterus, there is often a risk of rupture. Most ectopic pregnancies end in spontaneous miscarriage. The absence of a yolk sac in the intrauterine dark area of 5 mm or less does not exclude ectopic pregnancy. Abdominal pain in early pregnancy is distinguished from abdominal pain in spontaneous abortion. Abdominal pain associated with spontaneous abortion should be the abdominal pain that occurs when the embryo is about to be expelled after abortion, which itself does not produce abdominal pain. In contrast, abdominal pain after 7 weeks of gestation, if intrauterine pregnancy has been confirmed by ultrasound and the fetal heartbeat is good, it may be related to pelvic congestion and straining of the surrounding tissues due to the enlargement of the uterus, in addition to the distension of the ovaries. There is no need to be too concerned. If the embryo is aborted, the mother will have to expel the “dead embryo” in a self-protective manner, and bleeding and abdominal pain will occur during the expulsion process. Does abdominal pain during pregnancy mean that the embryo has stopped? The theory that miscarriage before 12 weeks of gestation is characterized by bleeding followed by abdominal pain is not new and has been published in many obstetrics and gynecology textbooks. If the embryo is aborted before 12 weeks of gestation, the mother will expel it in order to protect herself, and the bleeding will occur first when the chorion is detached from the meconium and the mother, and the abdominal pain will occur only during the expulsion of the embryo wrapped in the detached membranes, thus showing bleeding first and then abdominal pain. It is not very likely that abdominal pain will be caused by miscarriage within 6 weeks of pregnancy, and it is more appropriate to call it “fertilized egg miscarriage” rather than embryonic miscarriage, which is more like menstruation. If a woman in early pregnancy (within 12 weeks of conception) has just had an ultrasound within a week to confirm an intrauterine pregnancy with a good fetal heartbeat, should she repeat the ultrasound immediately if she has abdominal pain? I think it is not necessary. If the embryo is aborted after the ultrasound, there should be no abdominal pain for a short period of time, as the abdominal pain is caused during the expulsion of the embryo. I think it should take at least two weeks from the time of embryonic abortion to the time of expulsion, which is the time of luteal atrophy. Abdominal pain during pregnancy is a very common symptom. In today’s medical development, you should not use abdominal pain to determine whether it is an ectopic pregnancy, to judge the development of the embryo, or to predict whether embryonic abortion will occur. Otherwise, it will bring you unnecessary psychological burden.