The safety of psychotropic medication in pregnancy cannot be determined because it is not possible to conduct prospective controlled experimental studies in humans. Consequently, the choices for psychotropic medication in pregnancy are based on information that has limitations, which are: the inability to control whether it is an effect of the disease itself or the medication; bias in case report information; and a lack of information from human trials. For some new drugs, earlier reported adverse effects may or may not be replicated, and the risks and benefits of discontinuing or continuing the use of the drug are based on what is called a best guess assessment. There is little information on long-term consequences, even for medications that have been used for many years. In addition, because pregnancy increases the risk of psychiatric illness and relapse, how patients and their families perceive the pros and cons of medication is critical, and sometimes a key factor in the decisions made by therapists. I. Discussion of Treatment Options for Pregnant Women For a pregnant woman with a mental illness, a thorough discussion with the patient and her guardian is needed before deciding on a medication regimen. If possible, it is best to provide individualized written materials to explain the various risks. The absolute and relative risks of medication should be explored together. Risks should be expressed using natural probabilities rather than percentages, e.g. 1 in 10 rather than 10%. In general, the discussion needs to address the following. (i) The ability of pregnant women to deal with the untreated phase of the illness or subthreshold symptoms (subthreshold symptoms). The potential impact of untreated mental disorders on the fetus or infant. Risks associated with abrupt discontinuation of medication. (iv) The severity of previous episodes of illness, response to medication, and personal preference for treatment. ⑤ What is the risk of congenital malformations in the fetus of a pregnant woman who does not have a mental disorder. (6) The possible harms of medication during pregnancy and after delivery, including the harms of overdose and some uncertain risks. (vii) For women who are taking medication and are pregnant, discontinuing use of the medication does not eliminate the risk of fetal malformations. Second, the basic principles of prescribing psychotropic drugs during pregnancy (1) For all female patients with mental disorders of childbearing age: ① The possibility of pregnancy should be frequently discussed with them (because many pregnancies are unplanned). (ii) Advice should be given to avoid as much as possible medications that are contraindicated for pregnant women (especially valproate and carbamazepine). If these drugs are prescribed, the patient should be informed that they are teratogenic even if she does not intend to become pregnant. (2) For pregnant women with newly diagnosed mental illnesses: ① Avoid all medications during the first trimester of pregnancy (during major organ formation) unless the benefits clearly outweigh the disadvantages. (ii) When medication must be used, the lowest effective dose of the medication should be used. (3) For those who are taking psychotropic medications and intend to become pregnant: ① If the patient is currently doing well and the likelihood of a relapse is low, discontinuing the medication may be considered. (ii) For patients with severe psychosis and a high risk of relapse, discontinuing the medication is not a wise choice. Switching to a medication that has little effect on the fetus may be considered, but the patient should be informed that switching may increase the risk of relapse. (4) For those who are taking antipsychotics and are pregnant: ① It is not wise to stop medication abruptly in patients with severe psychosis and a high risk of relapse. Relapse will be more harmful to the mother and child than continuing effective medication. (ii) It is recommended to maintain the current effective medication and not to easily change medication or minimize medication to reduce the amount of drug exposure to the fetus. (5) For patients who smoke: nicotine replacement therapy is recommended. (6) For all pregnant women: ① Make sure both parents are involved in all decisions. ② Use the lowest effective dose of medication that is least harmful to the pregnant woman and fetus. ③ Keep the types of drugs to a minimum. ④ Adjust the drug dose according to the course of the pregnancy. The total amount of blood in the body increases by almost 30% during the second trimester (second half) of pregnancy, when the dose of medication often needs to be increased. Blood concentration monitoring is useful. It is important to note that the activity of liver enzymes varies greatly during pregnancy, with CYP2D6 activity increasing by almost 50% and CYP1A2 activity decreasing by more than 70% in the second trimester. ⑤ Consider referral for perinatal medicine services. (vi) Ensure necessary fetal monitoring and be aware of the potential problems that the drug may have on the fetus at birth. ⑦ Inform the obstetrician of the patient’s psychotropic medication use and possible complications. (viii) Monitor the infant postnatally for signs of drug withdrawal. ⑨ Record all of the patient’s diagnostic and therapeutic decision-making processes. III PREGNANCY AND POSTPARTUM PSYCHIATRICS Pregnancy increases the incidence and recurrence of psychiatric disorders. In the general female population, the probability of developing perinatal psychiatric disorders is 0.1% to 0.25%, and the relative risk of psychiatric disorders increases 20-fold (to 30% to 50%) in the month following delivery. The probability of recurrence after another birth is 50 to 90% in those who have previously suffered from postpartum psychosis. Untreated perinatal psychosis in pregnant women can lead to serious consequences. Therefore, medication is necessary for those with severe illness. 1, antipsychotic medication (1) First-generation antipsychotics (FGAs) Generally, FGAs are considered to have the lowest risk of teratogenicity. Most of the information comes from low-dose phenothiazines for the treatment of primary gestational eclampsia with severe vomiting (this type of drug has an increased risk of congenital malformations), some of which suggests that there is an increased risk of congenital malformations, but there is no congregation of congenital malformations (clustering) occurs. This result suggests that the severity of maternal eclampsia may have a greater impact on malformations than the therapeutic drug. Haloperidol may cause limb malformations, but even if true, this probability is quite low. In addition, there have been reports of FGAs causing neonatal dyskinesia and phenothiazines causing neonatal jaundice. In summary, it remains unclear whether FGAs are completely harmless to the fetus and its subsequent growth and development. However, the results of decades of use of these drugs suggest that any risk is not significant, and most studies confirm this hypothesis. (2) Information on second-generation antipsychotics (SGAs) is accumulating, with relatively more studies on olanzapine and clozapine. Some studies have found that olanzapine may cause low birth weight and increase the likelihood of neonatal admission to the intensive care unit, and may result in the birth of a macrosomic child, which may be associated with an increased risk of gestational diabetes with olanzapine. Although olanzapine is relatively safe in causing fetal congenital malformations, it has been reported to cause hip dysplasia, meningeal protrusion, lid margin adhesions, and neural tube defects. Of these, neural tube defects are more likely to be related to pre-pregnancy obesity than drug effects. Most importantly, olanzapine has not been found to cause congenital malformations with clustering. Clozapine does not appear to increase the risk of fetal malformations, although the incidence of gestational diabetes and neonatal convulsions may be increased. Fetal deaths have been reported in mothers who overdosed, and fetal or neonatal agranulocyte deficiency should be a concern.NICE (National Institute for Health and Clinical Excellence) recommends that pregnant women be switched to other antipsychotic medications. However, most pregnant women taking clozapine relapse after switching. Therefore, based on a combination of available information, it is recommended that clozapine should be continued. Limited information suggests that risperidone and quetiapine have no significant teratogenic effects in humans. Research information on other second-generation antipsychotics is lacking so far. 2. Summary of recommendations for antipsychotic medication for pregnant women (1) For women with a history of psychosis who are still taking antipsychotics, planning a pregnancy should be discussed as early as possible. (2) It should be noted that drug-induced hyperprolactinemia can lead to infertility. Consideration should be given to switching to other medications at this time. (3) For women with a history of psychosis, especially those with recurrent episodes, it is best to maintain antipsychotic medication during pregnancy so as to avoid the possibility of needing to increase the dosage or combination of medications in the event of a relapse of the illness, thus reducing fetal exposure to the medication. (4) There is more experience with the use of chlorpromazine (which can cause constipation and sedation), trifluoperazine, haloperidol, olanzapine, and clozapine (both of these SGAs may cause gestational diabetes). If the patient is taking other medications, the most recent medication guidelines should be used as a guide, and easy changes in treatment regimen may be both unnecessary and unwise. (5) NICE advises against the use of long-acting agents and anticholinergic drugs in pregnant women. (6) A few experts recommend stopping antipsychotics 5-10 days before delivery, however, this may cause withdrawal symptoms in both mother and baby. A mixed feeding regimen (breastmilk/cow’s milk) may reduce withdrawal symptoms in the infant. If the patient is taking second-generation antipsychotics, it is not necessary to stop the medication. Fourth, pregnancy and postpartum depression A large number of studies have shown that: about 10% of pregnant women suffer from depressive disorders, 16% have self-limiting depressive-like reactions, and most postpartum depression develops in the prenatal period. There is a significant increase in new psychiatric disorders in the first three months after delivery, of which at least 80% are mood disorders (mainly depressive episodes). Those with a previous history of depressive episodes are at significantly higher risk of having an episode during pregnancy or postpartum, and bipolar disorder has the highest risk of recurrence. In fact, the use of antidepressants during pregnancy is common. In the Netherlands, up to 2% of pregnant women take antidepressants during early pregnancy (first trimester) (Ververs et al., 2006); in the United States, about 10% of pregnant women take antidepressants during pregnancy, and this percentage is increasing (Alwan et al., 2011), with the most widely used being the SSRIs. Depressed patients have a high rate of relapse after stopping medication.Cohen et al. (2006) found that women who were well treated with antidepressants had relapse rates of 68% versus 26% for those who stopped taking medication during pregnancy versus those who did not. Some studies have suggested that antidepressants may increase the risk of spontaneous abortion (although these studies failed to control for other confounding factors). Also, antidepressants may increase the risk of preterm labor in pregnant women, neonatal respiratory distress, low Apgar scores at birth, and admission to the neonatal intensive care unit. Some antidepressants may be associated with certain specific congenital malformations, but it is very rare and most of these results fail to be reproduced. The effect of the duration of antidepressant use on the fetus, on the other hand, has shown conflicting results, and the effects of antidepressants on neurologic development have been reported in few studies to date. 1, Tricyclic antidepressants (TCAs) (1) Most studies have found no significant harm to the fetus from TCAs, so they are more widely used in pregnancy. (2) Limited information suggests that TCAs taken during pregnancy have no effect on their future growth. (3) Some studies have reported that TCAs taken during pregnancy can increase the risk of preterm labor; taking them in the second trimester of pregnancy can cause neonatal withdrawal reactions, but the symptoms are generally mild and self-limiting. (4) Some experts recommend the use of anticholinergic and antihypertensive effects of the weaker nortriptyline and nortriptyline. 2.Selective 5-hydroxytryptamine reuptake inhibitors (SSRIs) Some evidence suggests that SSRIs do not seem to cause significant teratogenicity. And most studies suggest that fluoxetine is safe.Thormahlen et al. (2006) reported that paroxetine may cause cardiac malformations. Subsequently, Berard et al. (2007) also found a greater risk after high doses of paroxetine in early pregnancy (725 μg/day). However, this result could only be replicated by subsequent studies. Taken together, SSRIs may cause the following problems: they may lead to a shorter gestation period (on average, one week less), spontaneous abortion and low birth weight (on average, a 175 g weight loss); the longer the fetus is exposed to the drug in utero, the greater the probability of producing a low-birth weight baby and respiratory distress; three groups of symptoms can be seen in the newborn after taking an SSRI in the late stages of gestation: symptoms related to serotonin toxicity, symptoms related to the withdrawal of the antidepressant, and preterm labor. Sertraline in late pregnancy can cause low Apgar scores in newborns, and paroxetine may cause neonatal complications if taken late in pregnancy, presumably related to rapid withdrawal; other SSRIs have similar, but milder, effects. SSRIs do not appear to have much effect on fetal neurodevelopment, although this information is not conclusive enough; Nulman et al. (2002) suggest that depression itself may have a greater adverse effect on fetal growth and development than drugs. 3, other antidepressant treatment Limited information suggests that: venlafaxine is not potentially teratogenic but may lead to neonatal withdrawal, mid-pregnancy venlafaxine may produce preterm infants; bupropion and mirtazapine may increase the rate of spontaneous abortions; fetal exposure to bupropion may increase the risk of attention deficit hyperactivity disorder in childhood. Because there is little information on the safety of the above drugs in pregnant women and fetuses, they are not recommended for use in pregnant women at this time. Monoamine oxidase inhibitors should be avoided during pregnancy as they may increase the risk of congenital malformations and hypertensive crises. Although general anesthesia still carries some risk to the mother and fetus, there is no evidence that electroconvulsive therapy (ECT) during pregnancy is harmful to the mother or fetus. Therefore, for refractory depression, NICE recommends the use of ECT before or instead of a combination of drugs. omega-3 fatty acids may be used as therapeutic agents, although there is insufficient research information on their effectiveness and safety. 4. Summary of recommendations for antidepressant treatment in pregnancy (1) For patients taking antidepressants and at high risk of relapse, it is best to maintain medication before and after pregnancy. (2) For patients with moderate or severe depression during pregnancy, they should be treated with antidepressants. (3) There is more experience with the use of amitriptyline, milpramine and fluoxetine. Among them, both amitriptyline and milpramine can cause constipation and sedation, and may also lead to withdrawal syndrome; fluoxetine can increase the risk of preterm labor and low-birth-weight babies. If a pregnant woman is already taking another antidepressant, she should look for the most recent medication recommendations. Since experience with other medications is increasing, it may be unnecessary and unwise to change treatment regimens. Paroxetine may have a poorer safety profile than other SSRIs. (4) Relief of withdrawal symptoms in newborns may be an option to maintain breastfeeding and then switch to mixed feeding. (5) The use of SSRIs in the second trimester of pregnancy may increase the risk of persistent pulmonary hypertension in the newborn.