This topic is not in my area of expertise, so it’s funny to talk about it. However, there are so many friends and relatives around me, and there are so many misunderstandings, that I rarely see a more formal answer. I have also observed that many doctors, when explaining their patients’ conditions, open their mouths and say, “After this miscarriage, use birth control for 6 months! If you ask why, you only get a rhetorical question: Isn’t that what everyone says? From the patient’s point of view, many people also feel the need for such a period of “conditioning”, a little more professional will claim to let the “endometrial repair repair”. There is no basis for these ideas. Most abortions in early pregnancy, whether spontaneous, medical, or abortion, are very safe, with very few comorbidities and sequelae, and minimal damage to the body [1]. The recovery of the endometrium is marked by the normal menstrual flow. The endometrium is repaired when normal menstrual periods are restored. Okay, so just how long does it take to get pregnant again? The prestigious weekly medical journal British Medical Journal (BMJ) published a large cohort study in Scotland in 2010 [2], in which more than 30,000 women who had a miscarriage (their miscarriage occurred before 24 weeks of pregnancy) were divided into three groups: pregnancy within 6 months after miscarriage, pregnancy between 6 and 24 months after miscarriage, and pregnancy more than 24 months after miscarriage. It was found that the group of women who had a pregnancy within 6 months of miscarriage had the best birth outcomes (both mother and baby); those who had a second pregnancy more than 24 months after miscarriage had the worst birth outcomes. These outcomes included: recurrent miscarriage, intrauterine death, ectopic pregnancy, cesarean section, preterm birth, and low birth weight. Therefore, the argument for 6 months of post-abortion contraception does not hold water. A prospective study published in 2015 in the journal of the American Congress of Obstetrics and Gynecology (Grayskin Journal) divided women who had a miscarriage before 20 weeks of gestation into two groups: those who had a pregnancy within 3 months after miscarriage and those who had a pregnancy 3-6 months after miscarriage [3]. It was found that there was no significant difference in live birth rate and adverse pregnancy outcomes (including miscarriage rate) between the two groups. The average time from the end of miscarriage to pregnancy in the former group was less than 9 weeks! That means that you can get pregnant two or three months after the miscarriage, not to mention six months, without affecting the health of the child at all! For those women who have a so-called “biochemical pregnancy” (urine or blood tests suggesting pregnancy, but the ultrasound never sees the gestational sac), they recommend actively trying to have a baby that month. My wife also experienced an embryonic abortion where the baby lost its heart at 9 weeks gestation, which was a very sad event and directly changed our work schedule. When we got our period back, we didn’t delay and were still active in having a baby. As a result, our baby was born without any problems and looks very cute so far. In conclusion, 6 months of rest is not necessary after an early pregnancy miscarriage, and maybe not even 3 months. Many doctors and patients ask, why is this? I don’t know, and neither do researchers. Many explanations have been proposed, such as the immune theory, such as the trophoblast theory, and so on, all of which have yet to be proven. In other words, we don’t know the “cause”, but we already know the “effect”. The mysterious “cause” should be left to clinicians and basic pathophysiologists. On the other hand, we already know that in cases of induced labor or full-term delivery at 20 weeks of gestation or more (above, not below), there is a significant increase in fetal and neonatal morbidity if the next pregnancy is less than 18 months apart [4, 5]. It has also been found that neonatal morbidity is lowest in pregnancies with an interval of 12-24 months between pregnancies (pregnancies at more than 20 weeks of gestation). There are unfavorable conditions at too short an interval (less than 6 months) or too long an interval (more than 60 months), with intervals of less than 6 months being the worst and many problems occurring in the mother’s body [6]. Why does this happen? It has been suggested that it is related to folic acid metabolism, but the exact mechanism remains unclear to us. The universe is vast, the truth is deep, what we know is only superficial, what we do is only imitation. However, if we are creative and find another way, we can’t stop anyone. Maybe we can really find something else and see the world. Oh.