Q&A: Is it sinful to have marital relations during pregnancy? Yes, according to the saints and fathers of the Church

Question: Is it sinful to have marital relations during the pregnancy of the wife?

Answer: Many have thought that Pope Pius XI’s encyclical Casti Connubii teaches that one may lawfully have marital relations during the wife’s pregnancy, but Casti Connubii is highly ambiguous and it is very hard to understand whether it teaches that one may lawfully have marital relations after the woman have become pregnant. Casti Connubii teaches that spouses can perform the marital act during those times when “new life cannot be brought forth”, and this is interpreted by some to give permission for spouses to perform the marital act during a woman’s pregnancy, but the Pope then goes on to state that this action is only lawful “so long as they are subordinated to the primary end [that is, Procreation of children]” and so, this last sentence seem to teach that one may not perform the marital act during the pregnancy of the woman, since the primary end and motive of procreation is already fulfilled.

There is no official and dogmatic Papal Church teaching, as far as we know, that directly teaches that marital relations during a pregnancy is a sin, but that does not mean that it is not a sin, and especially so since the Popes, Fathers, Saints, and Doctors of the Church throughout the ages opposed marital relations without the intent to procreate. This thus seems to be the Catholic Tradition from the beginning.

In contrast to the lack of quotations from the Popes, Fathers and Saints of the Church that allows spouses to perform the marital act during pregnancy, there are, however, many quotations that address this question directly from the Fathers and early writers of the Church that rejects this act. The Holy Fathers and Church Tradition (in all the quotes we’ve found on the subject) unanimously teach that sexual activity during the infertile period of pregnancy as well as menstruation must be avoided at all times since it is unnatural and unreasonable to sow one’s seed when one “awaits the harvest.”

Athenagoras the Athenian (c. 175 A.D.): “After throwing the seed into the ground, the farmer awaits the harvest. He does not sow more seed on top of it. Likewise, to us the procreation of children is the limit of our indulgence in appetite.” (A Plea For the Christians, Chapter XXXIII.--Chastity of the Christians with Respect to Marriage)

Nature itself tells us through our inborn instinct that it is unreasonable and unnatural to sow a seed in the same place where a seed is already growing.

In reference to the same issue, St. Clement of Alexandria (c. 195 A.D.) writes: “To…a spiritual man, after conception, his wife is as a sister and is treated as if of the same father.” (The Stromata or Miscellanies, Book VI, Chapter XII) St. Clement also pointed out that in all the Jewish scriptures there was not a single instance in which “one of the ancients approached a pregnant woman” and taught that the avoidance of sexual relations from the time one’s wife became pregnant to the time of the child’s weaning was “a law of nature given by God.” (St. Clement of Alexandria, The Stromata or Miscellanies, Book III, Chapter XI, Section 71, 72)

St. Augustine, in his book On The Good of Marriage (A.D. 401), likewise agreed with the Church’s tradition that performing the marital act during pregnancy is unreasonable and unnatural since “necessary sexual intercourse for begetting [of children] is free from blame, and itself is alone worthy of marriage. But that which goes beyond this necessity [of begetting children] no longer follows reason but lust…” (Section 11) He also taught that marital relations during pregnancy “are the sins of the married persons themselves, not the fault of marriage.”

St. Augustine, On the Good of Marriage, Section 5, A.D. 401: “There also are men incontinent to such a degree that they do not spare their wives even when pregnant. Therefore, whatever immodest, shameful, and sordid acts the married commit with each other are the sins of the married persons themselves, not the fault of marriage.”

In his book Against Julian, St. Augustine shows us that conjugal chastity: “combats [carnal concupiscence] in even more valiant fashion in regard to the act of conjugal union, lest there be indulgence beyond what suffices for generating offspring. Such chastity abstains during menstruation and pregnancy, nor has it union with one no longer able to conceive on account of age. And the desire for union does not prevail, but ceases when there is no prospect of generation.” (St. Augustine, Against Julian, Book III, Chapter 21:43) Thus the conception of children is “the one alone worthy fruit… of the sexual intercourse.” (St. Augustine, On the Good of Marriage, Section 1) No other aspect of the marital act can be described as “worthy.” Therefore, when a husband engages in marital relations during those times when his wife is pregnant, nursing, or menstruating, the husband or the wife or both are seen as seeking the unworthy fruit of sexual pleasure.

Two activities recommended by some NFP teachers are having sex during menstruation and during pregnancy, both of which the earliest extant Church Canons, the Apostolic Constitutions (c. 375 A.D.), specifically reject: “When the natural purgations do appear in the wives, let not their husbands approach them, out of regard to the children to be begotten; for the law has forbidden it, for it says: "Thou shalt not come near thy wife when she is in her separation." [Lev. xviii. 19; Ezek. xviii. 6.] Nor, indeed, let them frequent their wives’ company when they are with child. For they do this not for the begetting of children, but for the sake of pleasure. Now a lover of God ought not to be a lover of pleasure.” (The Sacred Writings of Apostolic Teaching and Constitutions, Book V, Chap. XXVIII)

St. Caesarius of Arles (c. 468-542) tells us that marital relations during a woman’s menstruation can result in that “the children who are then conceived… be born as lepers, or epileptics, or perhaps even demoniacs”, thus showing us that it is a great necessity to abstain from marital relations during these times in order to not injure our children. He also adds that married people who perform the marital act during a woman’s pregnancy are worse than beasts.

St. Caesarius of Arles, Sermon 44:7: “Above all, no one should know his wife when Sunday or other feasts come around. Similar precautions should be taken as often as women menstruate, for the Prophet says: ‘Do not come near to a menstruous woman.’ [Ezech. 18:6] If a man is aware that his wife is in this condition but refuses to control himself on a Sunday or feast, the children who are then conceived will be born as lepers, or epileptics, or perhaps even demoniacs [that is, he means that it is common that this happens for such unrestrained and lustful spouses]. Lepers are commonly born, not of wise men who observe chastity on feasts and other days, but especially of farmers who do not know how to control themselves. Truly, brethren, if animals without intellect do not touch each other except at a fixed and proper time, how much more should men who have been created according to God’s image observe this? What is worse, there are some dissolute or drunken men who sometimes do not even spare their wives when they are pregnant. Therefore, if they do not amend their lives, we are to consider them worse than animals. Such men the Apostle addresses when he says: ‘Every one of you learn how to possess his vessel in holiness and honor, not in the passion of lust like the Gentiles who have no hope.’ [1 Thess. 4:4-5]”

St. Ambrose (c. 340-397) could rightly declare that it is shameful to continue to have sexual relations after pregnancy, and that those people who do this act “contaminate the former [the child] and exasperate [anger] the latter [God]”: “Youths generally assert the desire of having children and think to excuse the heat of their age by the desire for generation. How much more shameful for the old to do what is shameful for the young to confess. For even the young who temper their hearts to prudence by divine fear, generally renounce the works of youth when progeny [offspring] have been received. And is this remarkable for man, if beasts mutely speak a zeal for generating, not a desire for copulating? Indeed, once they know the womb is filled, and the seed received by the generative soil, they no longer indulge in intercourse or the wantonness of love, but they take up parental care. Yet men spare neither the embryo nor God. They contaminate the former and exasperate the latter. "Before I formed you in the womb," He says, "I knew you and sanctified you in your mother’s womb." [Jer. 1:5] To control your impatience, note the hands of your Author forming a man in the womb. He is at work, and you stain with lust the secret of the sacred womb? Imitate the beast or fear God. Why do I speak of beasts? The land itself often rests from the work of generating, and if it is often filled with the seeds thrown by the impatient eagerness of men, it repays the shamelessness of the farmer and changes fertility to sterility. So even in the elements and the beasts it is a shame to nature not to cease from generating.” (St. Ambrose, Archbishop of Milan, Exposition of the Gospel According to St. Luke 1:43-45)

St. Clement of Alexandria, The Stromata or Miscellanies, Book III, Chapter XI, Section 71, 72, On Marriage and Procreation (c. 198-203 A.D.): “Right from the beginning the law, as we have already said, lays down the command, “Thou shalt not covet thy neighbour’s wife,” [Ex. 20:17] long before the Lord’s closely similar utterance in the New Testament, where the same idea is expressed in his own mouth: “You have heard that the law commanded, ‘Thou shalt not commit adultery.’ But I say, ‘Thou shalt not lust.’” [Matt. 5:27-28] That the law intended husbands to cohabit with their wives with self-control and only for the purpose of begetting children is evident… For this reason you could not point to any place in Scripture where one of the ancients approached a pregnant woman; later, after the child is born and weaned, you might find that marriage relations of husbands and wives were resumed. You will find that Moses’ father kept this principle in mind. After Aaron’s birth three years passed before Moses was born. [Ex. 7:7] Again, the tribe of Levi observed this law of nature given by God, although they were fewer in number than any others which came into the promised land. [Num. 3:39] For a tribe does not easily grow to great numbers if their men have intercourse only within the legal marriage relationship and then wait until the end not only of pregnancy but also of breast-feeding.”

St. Clement of Alexandria, The Stromata or Miscellanies, Book II, Chapter XXIII, On Marriage and Procreation (c. 198-203 A.D.): “Far more excellent, in my opinion, than the seeds of wheat and barley that are sown at appropriate seasons, is man that is sown, for whom all things grow; and those seeds temperate husbandmen ever sow. Every foul and polluting practice must therefore be purged away from marriage; that the intercourse of the irrational animals may not be cast in our teeth, as more accordant with nature than human conjunction in procreation. Some of these, it must be granted, desist at the time in which they are directed, leaving creation to the working of Providence.”

Origen (c. 184-254), Homilies on Genesis, Homily V, Section 4, On Lot And His Daughters: “Let the married women examine themselves and seek if they approach their husbands for this reason alone [for having children], that they might receive children, and after conception desist. For those [virtuous] women... when they have attained conception, [rightly] do not later assent to copulation with a man. But some women, for we do not censure all equally, but there are some who serve passion incessantly, like animals without any distinction, whom I would not even compare to the dumb beasts. For even the beasts themselves know, when they have conceived, not to further grant opportunity to their males. The divine Scriptures also censures such when it says: "Do not become like the [sterile] horse and the mule who have no understanding," [Ps. 31:9] and again, "They have become stallions." [Jer. 5:8] But, O people of God, "who love Christ in incorruption," [Eph. 6:24] understand the word of the Apostle in which he says: "Whether you eat or drink or whatever else you do, do all to the glory of God." [1 Cor. 10:31] For his remark after eating and drinking, "whatever else you do," has designated with a modest word the immodest affairs of marriage, showing that even these acts themselves are performed to the glory of God if they are attended to with a view to posterity [offspring] alone.”

“In fact, a good Christian should not only observe chastity for a few days before he communicates, [that is, before he receives the Holy Eucharist] but he should never know his wife except from the desire for children. A man takes a wife for the procreation of children, not for the sake of lust. Even the marriage rite mentions this: ‘For the procreation of children,’ it says. Notice that it does not say for the sake of lust, but ‘for the procreation of children.’ I would like to know, dearly beloved, what kind of a harvest a man could gather if he sowed his field in one year as often as he is overcome by dissipation and abuses his wife without any desire for children. If those who are unwilling to control themselves plowed and sowed repeatedly their land which was already sown, let us see in what kind of fruit they would rejoice. As you well know, no land can produce proper fruit if it is sown frequently in one year. Why, then, does a man do with his body what he does not want done with his field?” (St. Caesarius of Arles, Sermon 44:3)

God desires all couples to have some abstinence from the marital act sometimes during the year, as St. Paul tells us, so that their prayer life and spiritual growth can happen without them at every time being weighed down by the mass of carnal thoughts and temptations.

St. Finnian of Clonard (470-549), The Penitential of Finnian, #46: “We advise and exhort that there be continence in marriage, since marriage without continence is not lawful, but sin, and [marriage] is permitted by the authority of God not for lust but for the sake of children, as it is written, ‘And the two shall be in one flesh,’ that is, in unity of the flesh for the generation of children, not for the lustful concupiscence of the flesh. Married people, then, must mutually abstain during three forty-day periods in each single year, by consent for a time, that they may be able to have time for prayer for the salvation of their souls; and after the wife has conceived he shall not have intercourse with her until she has borne her child, and they shall come together again for this purpose, as saith the Apostle. But if they shall fulfill this instruction, then they are worthy of the body of Christ… and there they shall receive the thirty-fold fruit which as the Savior relates in the Gospel, he has also plucked for married people.” (Medieval Handbooks of Penance by John T. McNeil and Helen Gamer. New York: Columbia University Press, 1938)

Thus, the teaching of the Church Fathers is very clear that all sexual relations during pregnancy are to be avoided. “The procreation of children is the remit and ordinance of those who are joined together in marriage; and their objective is that their children be good.... See how Moses in his great wisdom symbolically rejected sowing one’s seed fruitlessly, saying "You shall not eat the leopard or the hyena" [Deut. 14:7]. He did not want human beings to share their character or to experience lust of the same magnitude as theirs, for it is said that these animals suffer from a mad frenzy to have sexual intercourse.... It is lawful for you to take sensual pleasures only from your wife in order to beget legitimate offspring, for only these pleasures are lawful according to the Word.... For this reason, Moses himself prohibited his people from sleeping even with their own wives in cases where they were subject to menstrual flows.... For pleasure alone, when experienced in marital intercourse, is unlawful, unjust and foreign to reason. Again, Moses ordered men not to sleep with pregnant women until they gave birth...” (St Clement of Alexandria, The Paedagogus, c. 198 A.D.)

It is bad to touch a woman during pregnancy since it gives the child in the womb “many sinful impulses” according to Anne Catherine Emmerich

In the revelation of Anne Catherine Emmerich, entitled the “Life of the Blessed Virgin Mary”, we read the following interesting points about marital relations during pregnancy:

“It was explained to me here that the Blessed Virgin was begotten by her parents in holy obedience and complete purity of heart, and that thereafter they lived together in continence in the greatest devoutness and fear of God. I was at the same time clearly instructed how immeasurably the holiness of children was encouraged by the purity, chastity, and continence of their parents and by their resistance to all unclean temptations; and how continence after conception preserves the fruit of the womb from many sinful impulses. In general, I was given an overflowing abundance of knowledge about the roots of deformity and sin.” (Anne Catherine Emmerich, Life of the Blessed Virgin Mary, II. The Immaculate Conception)

Despite this, many lustful people will not agree with what Anne Catherine Emmerich had to say here, and some may even be offended by it. The reason for this is because these people and others want to deceive themselves into thinking that there is nothing wrong about lust or concupiscence. Yes, they even claim this even though they know and are fully aware of that lust leads countless of souls to Hell and eternal damnation. However, whether or not they want to agree with it or not, it’s just a fact that the sexual lusts and temptations that urges people to commit sins of the flesh is an evil product of the fall, and of original sin. In other words, humans were not originally intended to experience concupiscence and temptations of the flesh according to God’s perfect plan for humanity, but it ended up in that way because of Adam and Eve’s transgression. If a person is honest with himself he will understand that this is true. However, most people want to deceive themselves and therefore choose to overlook this fact.

In summary, the definition or meaning of the revelation of Anne Catherine Emmerich is that lust is evil and that a couple’s marital relations during pregnancy will effect the child in a negative way, inflicting many sinful impulses upon the child. Anne Catherine Emmerich is clear that “continence after conception preserves the fruit of the womb from many sinful impulses.” The sensuality and sinful impulses that will be aroused by many spouses’ sexual relations during pregnancy is thus a great evil that will affect both husband and wife, and their future child, in a negative way. Parents are inextricably bound together to their children after the conception of the child according to the book of Tobit in the Holy Bible, and any act the parent will do, whether good or evil, will effect their child for better or for worse. Why is it that some children are tempted more to commit sin than others? It is in almost every case, because of the parents’ lustfulness or sins. Because of this, parents should to do all in their power to abstain from marital relations during all pregnancies.

The biblical Book of Tobit also teaches that the virtue and abstinence of the parents will effect whether their children will be born whole or with defects of different kinds. Thus, we read that “the third night [of praying and observing chastity before having sexual relations] thou shalt obtain a blessing that sound children may be born of you.” The blessing on the third night of “sound children” obviously means that those couples who do not perform the marital act for the sake of lust or too often, and who are virtuous and wait for three days in accordance with the promise of Holy Scripture, will receive a child without birth deformities or defects. This may be hard for many to believe, but this is really and truly what Holy Scripture is promising and saying.

Tobias 6:18, 20-22 “[St. Raphael said to Tobias:] But thou when thou shalt take her, go into the chamber, and for three days keep thyself continent from her, and give thyself to nothing else but to prayers with her. … But the second night thou shalt be admitted into the society of the holy Patriarchs. And the third night thou shalt obtain a blessing that sound children may be born of you. And when the third night is past, [of praying and observing chastity] thou shalt take the virgin with the fear of the Lord, moved rather for love of children than for lust, that in the seed of Abraham thou mayst obtain a blessing in children.”

It is sad to see that none today seem to care anything about these promises or virtuous deeds that promise these remarkable and wondrous graces that Our Lord said he would bless a virtuous couple with. One could think that even a worldly or ungodly couple would appreciate the grace of not receiving a child that is deformed and that they, if they believed in God or were aware of these promises, would act in accordance to the words of the Holy Scripture; but now neither “Catholics” or so-called Christians nor any people of the world care anything about these words of our Lord that promises the inestimable grace of receiving “a blessing that sound children may be born of you.”

St. Bridget was also revealed the truth of the spiritual danger of having marital relations during pregnancy in a spiritual revelation. In it she saw a man that was tormented in purgatory. St. Bridget was allowed to communicate with this tormented soul. She asked the man about the specific reasons why he escaped Eternal Hell. He answered saying: “The third [reason I escaped being eternally condemned to burn in Hell] is that I obeyed my teacher who advised me to abstain from my wife’s bed when I understood that she was pregnant.” (The Revelations of St. Bridget, Book 9 or Appendix)

In truth, Sister Anne Catherine Emmerich’s Revelations of what Our Lord preached during his earthly life also shows us that He “rigorously commanded perfect continence after the period of conception.” “Jesus once more spoke to them of the duties of the married state. . . . He inculcated the observance of modesty and purity, bade them in all their actions to aim at purity of intention, exhorted them to prayer and renunciation, and rigorously commanded perfect continence after the period of conception (Volume Three, pp. 515–516).” “Jesus then explained to them that they who enjoy [themselves] on earth have to render an account hereafter, and that this life is one of penance (Volume Three, p. 540).” (The Life of Jesus Christ and Biblical Revelations of Anne Catherine Emmerich)

In addition to the above facts, it is also evident that many spouses may be more inclined to commit some form or another of sexual sin during this time period and that they might put too much heart or affection in the sexual act at this time due to the fact that conception cannot occur again, and so they might indulge a little too often or unreasonably and love the act a little too much, and more than what is suitable. “For where your treasure is, there will your heart be also.” (Luke 12:34) “Men shall be… lovers of pleasure more than of God.” (2 Timothy 3:1-5)

Thus, it is totally clear that those who are having marital relations during pregnancy, and who do not practice virtue, are endangering their own and their child’s spiritual welfare. During pregnancy, the primary purpose of procreation that the Church teaches that spouses always must perform the marital act for is not possible to be fulfilled and thus, it is a defective action to have marital relations during this time. We see this distinction being made in the Church’s teachings in these words: “Since, therefore, the conjugal act is destined primarily by nature for the begetting of children” (Pope Pius XI Casti Connubii, #54).

Marital relations during pregnancy can also sometimes be dangerous to the child and lead to a premature birth or a stillborn child. Many times there also exist a high risk for preterm labor or a medical condition, such as infection, or any other valid reason that makes it absolutely necessary to abstain from the marital act. If the doctor has said that it can cause further complications to the pregnancy – or if there is any risk to engage in marital intercourse during this time period – it is a mortal sin to deliberately engage in marital intercourse at this time. And the husband has no right to ask for the debt during this period. No masturbation, oral sex or other sinful acts are allowed as a substitute during this time period either.

The fact of the matter is that you endanger your child’s well-being by having sex during pregnancy, and that is a fact of science. Dr. Desouza comments concerning this issue and makes clear the many dangers with having sex during the pregnancy of the woman: “Just remember, sex may trigger labour. You wouldn’t want a miscarriage or a premature delivery, would you? Avoid sex if you are pregnant [and] 1. have had episodes of previous miscarriages 2. have experienced difficulty conceiving 3. have had episodes of lower pelvic/back pain and spotting/bleeding during your first trimester 4. you are told by your obstetrician that you are at high risk of premature labour. There are many reasons that put you on a high risk of premature labour. Carrying more than 1 baby (e.g. twins, triplets), previous infections (especially HPV infections), smoking during pregnancy and having had previous premature births are some of the reasons to name a few.”

It is no coincidence that there are complications to pregnancy by having sex during pregnancy, for God speaks to us commonly through signs and effects in this world, and one of His greatest ways to get heard in this world is to inflict some suffering on us, as He does when He allows illnesses, plagues, or wars to harm us, similar to how a parent chastises his disobedient son.

Doctors usually recommend some abstinence after labor, usually four to six weeks before resuming intercourse. This allows time for the woman to heal after birth. Total abstinence, if needed, is required during this time period according to the doctor’s recommendation.

The Old Testament also confirms that Our Lord wants spouses to practice chastity for a while after the birth of the child.

Leviticus 12:1-5 “And the Lord spoke to Moses, saying: ‘Speak to the children of Israel, and thou shalt say to them: If a woman having received seed shall bear a man child, she shall be unclean seven days, according to the days of the separation of her flowers. And on the eighth day the infant shall be circumcised: But she shall remain three and thirty days in the blood of her purification. She shall touch no holy thing, neither shall she enter into the sanctuary, until the days of her purification be fulfilled. But if she shall bear a maid child, she shall be unclean two weeks, according to the custom of her monthly courses, and she shall remain in the blood of her purification sixty-six days.’”

Since the Old Testament teaches that a person who becomes defiled cannot touch other people during the time that they are unclean, this shows us that God wants the spouses to abstain from the marital act for a while after they have received the child.

One must really marvel over how the members of the Christian Church, (who should be more virtuous than the people of the Jewish Old Testament religion) have fallen into this degraded and filthy custom of having marital relations during a woman’s pregnancy or menstrual period. The Old Law was only a shell and a sign of the future things in the New Law, and even the Old Law forbade marital relations on many more occasions than the New Law does. The reason of why the Old Law forbade things that now are not sinful is because in the New Law, Our Lord wants us to do many good things, not because we are forced to do it, but only because we know that they are good in themselves, which is a more virtuous and meritorious act. Christian spouses should obviously act and live more virtuously and holy than those people in the Old Law did, since all Christians have received more graces and knowledge of Our Lord than those in the Old Law, and it is really a blemish on the Christian community that this is not happening. The amount of graces that are lost because of these filthy and unnecessary acts of lustful spouses is, sad to say, immeasurable and inestimable. “Men shall be… lovers of pleasure more than of God.” (2 Timothy 3:1-5)

It must also be made perfectly clear that natural infertility during pregnancy on the part of the woman is not a reward for the spouses to have “great sex” because they were “good” in fulfilling the marital duty (the procreation and education of children), as so many people today nowadays actually (and falsely) seem to believe.

It is reasonable to conclude that if women were not infertile during pregnancy, many bad husbands would be endangering the life of their wives by exposing them to too many childbirths at too short time intervals. Consequently, if women were not infertile during pregnancy, many more mortal sins would be committed by married and unmarried men since they then would be inclined to seek relief of their fleshly lusts in other ways or by other women, so as not to endanger the life of their own wife or mistresses.

Indeed, to St. Jerome and the rest of the Saints and Fathers of the Church, the indulgences granted to the marital act was not something good or praiseworthy because it only acts as a relief valve to avoid a greater evil: “Thus it must be bad to touch a woman. [1 Cor. 7:1] If indulgences is nonetheless granted to the marital act, this is only to avoid something worse. [1 Cor. 7:6] But what value can be recognized in a good that is allowed only with a view of preventing something worse?” (St. Jerome)

St. Clement of Alexandria (c. 198 A.D.): “Marriage in itself merits esteem and the highest approval, for the Lord wished men to "be fruitful and multiply." [Gen. 1:28] He did not tell them, however, to act like libertines, nor did He intend them to surrender themselves to pleasure as though born only to indulge in sexual relations. Let the Educator (Christ) put us to shame with the word of Ezekiel: "Put away your fornications." [Eze. 43:9] Why, even unreasoning beasts know enough not to mate at certain times. To indulge in intercourse without intending children is to outrage nature, whom we should take as our instructor.” (The Paedagogus or The Instructor, Book II, Chapter X.--On the Procreation and Education of Children)

Thus, in conclusion, we see that spouses should avoid all sexual acts during pregnancy since:

1. The passions of the mother and father are passed on to the embryo.
2. These passions disrupt in utero the child’s spiritual or physical development, or affect it in negative ways.
3. These passions are sinful according to the Fathers and Saints, and should be avoided.
4. Intercourse during pregnancy is, consequently, a form of sinful passion.
5. Therefore, one should refrain from intercourse during pregnancy for the sake of the child’s spiritual and physical development.

This shows us that because of the points 1-5, marital intercourse should be limited as much as possible, as not only sex during pregnancy effects one’s child detrimentally, but also one’s own lustfulness after the birth. This is, in fact, what is taught by the Fathers and the Saints, as well as many historical church authorities.

For those who want to read and learn a lot more on sexual ethics, I can recommend the following interesting and informative article that is absolutely packed with quotes from the popes, saints and fathers of the Church:

Sexual Pleasure, the Various Sexual Acts, and Procreation