Postpartum contraception is an important component of technical family planning services and is a special stage in a woman’s life. Due to the special nature of postpartum breastfeeding, the lack of knowledge about postpartum contraception, influenced by traditional concepts, often makes some women believe that postpartum breastfeeding without menstruation, low menstrual volume, irregularity or low number of sexual intercourse will not lead to conception. Tu et al [1] found that postpartum resumption of sexual intercourse was low in contraception, and about 40% of women did not take contraceptive measures and resulted in unintended pregnancy. Therefore, good postpartum contraception can reduce the rate of unintended postpartum pregnancy and help improve women’s reproductive health.
1, the physiological characteristics of postpartum women
Postpartum breastfeeding inhibits ovulation and affects changes in the hypothalamic – pituitary – ovarian gonadal axis related to the length of breastfeeding and the number of sucking. The long duration of sucking and the number of sucking sessions suppress the gonadal axis significantly, inhibit ovulation and achieve the contraceptive effect. Some authors reported that the number of sucking 10-15 times per day, breastfeeding around the clock, and the duration of breastfeeding for more than 15 min each time had a contraceptive effectiveness of 98% within 6 months [2]. The recovery of maternal fertility is related to the infant feeding pattern, once the infant starts to add complementary foods and mixed feeding. If the infant is no longer breastfed at night or the interval between breastfeeding is prolonged, then the pregnancy will occur as usual during the breastfeeding period. A significant delay in the return of postpartum menstruation has been reported in women who were fully breastfeeding for 4 months after delivery [3]. In China, the average recovery of menstruation and ovulation after childbirth in lactating women is about 8 months. The average time to return to ovulation after delivery in non-lactating women is 40-50 d, and the average time to return to menstruation is 55-60 d [1, 4]. The time to return to sexual life after childbirth is related to the level of education, ethnic culture, physical condition, and the condition of the newborn. In North American countries many women begin sexual intercourse before the 6-week postpartum checkup [5]. a survey of 570 women by Byed et al [6] found that 90% of women had sex 4 months postpartum, 19% began sex 1 month postpartum, and the average time to sexual intercourse was 7 weeks postpartum. Huang Yongmei et al [7] conducted a cross-sectional survey of 1819 postpartum women in 10 streets in Shanghai, and the average time to breastfeeding was 6.52 months, the average time to menstruation recovery was 4.94 months, the average time to sexual life recovery was 5.04 months, and the average time to start using contraceptives was 5.68 months. It can be seen that although women in China resume sexual life late after giving birth, the average time of implementation of contraceptive measures still lags behind the start of sexual life, and a significant proportion of postpartum women are exposed to the danger of having sex without contraceptive measures for the first time.
2.Characteristics of various postpartum contraceptive methods
2.1 Intrauterine device
2.1.1 Timing of postpartum insertion of IUD Postpartum insertion of IUD can effectively reduce unintended pregnancy, and the Population Council first advocated post-partum insertion of IUD in 1970. In 2000, the World Health Organization’s Medical Standards for the Selection of Contraceptive Methods pointed out that the time of postpartum insertion of IUD is within 48h after delivery, but the indications and contraindications must be strictly grasped and attention must be paid to aseptic operation. In China, a large number of clinical studies have concluded that the placement of IUD in both vaginal and cesarean deliveries should be done within 10 min of placenta delivery, i.e., the IUD should be placed immediately after delivery (immediatepostplacentalinsertion, IPPI) and placed to the center of the uterine fundus, and its dislodgement rate is significantly lower than that between 10 min and 48 h after delivery [8]. placement [8]. Moreover, two purposes are achieved in one procedure, especially simultaneous placement by cesarean section, which reduces both the operative procedure, infection, and complications. IUD placement should be delayed until 4 weeks postpartum if it has not been placed within 48 h postpartum, due to the higher rate of dislodgement when placed between 48 h and 4 weeks postpartum. The 42 days postpartum is the time for the mother to go to the hospital for postpartum checkup and child planning immunization, and using this time to place the IUD is acceptable and easy for family planning technology management.
2.1.2 Types of IUDs placed after delivery The rate of IUD shedding immediately after delivery is high, 10% for 1 year for vaginal delivery and 5% for cesarean delivery. The rate of shedding with placement by experienced physicians is less than 3%. Inert IUDs have a high shedding rate and are not suitable for immediate postpartum placement; copper-containing IUDs should be placed; one study reported a randomized comparison of TCu200 and MLCu250 IUDs, with a shedding rate of 9.0% for 1 year of immediate postpartum placement and up to 23.7% for inert serpentine IUDs. Most dislodgements of IUDs placed immediately postpartum occur 3 months after placement, so it is important to follow up after placement to detect dislodgements and treat them promptly. The fixed IUD (trade name GyneFix, referred to as the Ginny ring) has been in the Chinese market for more than 20 years and was invented by Wildermeersch, a Belgian physician, and consists of six small copper sleeves threaded onto a 2-0 gauge polypropylene surgical wire with a small knot or small non-degradable cone at one end of the surgical wire, which is fixed in the myometrium of the uterine fundus [9]. The Gini ring has a copper surface area of 330 mm2 and has low shedding characteristics, making it more suitable for immediate postpartum placement.
2.1.3 Methods of IUD placement in the immediate postpartum period Methods regarding the placement of IUDs in the immediate postpartum period can be placed unassisted or with devices, which have no significant effect on the effectiveness of immediate postpartum placement [10]. The IUD is placed 42 d after delivery, although the uterus is basically reopened and the uterine orifice is still loose, so it is easier to place the IUD. However, at this time, the uterus is still soft and the uterine wall is thin, so it is necessary to master the indications and operate carefully to prevent uterine damage. It should be noted that breastfeeding women tolerate better immediately after delivery, and the rate of removal due to bleeding and pain after placement is much lower than that of non-breastfeeding women.
2.2 Hormonal contraception
2.2.1 Long-acting monoprogestational preparations Depo-Provera (also known as medroxyprogesterone acetate, DMPA, medroxyprogesteroneacetate) is a long-acting preparation of progestational hormone alone that is currently widely used in clinical practice, with an efficiency rate of 99.7%. It has no adverse effects on the quality and quantity of breast milk or on infant growth and is more suitable for lactating women [11]. Lactating women receive injections 6 weeks after delivery Progestin is stored locally and released slowly after the injection. DMPA is administered within 5 days after delivery if not breastfeeding. 150 mg of DMPA per injection is given once every 3 months as a deep intramuscular injection. Its main side effect is irregular small amount of bleeding, which mostly occurs during the 1st to 2nd injection, and the incidence of amenorrhea increases with longer dosing time. Postpartum use of DMPA has little effect on menstruation, with the incidence of irregular bleeding accounting for only 50.0% of non-postpartum use. Other long-acting injectable agents are norethindrone enanthate (200 mg/stem), which is injected once for 2 months of contraception. There are also monoprogestational preparations such as extended-release preparations under implants type I and II and vaginal contraceptive rings.
2.2.2 Micro-pill oral contraceptive pills Micro-pill contraceptive pills are short-acting oral tablets of monoprogestin, with an efficiency rate of 95.0% or more. The commonly used progestins are 19-desmethyltestosterone derivatives, such as levonorgestrel, norethindrone, deoxynivalenolone, etc. The micropillar class does not contain estrogen and each tablet contains about 0.03-0.5 mg of progestin. usage 1 tablet per day, also taken during menstruation. Its characteristics women can actively control and resume reproductive function soon after discontinuation. It does not affect the secretion and quality of breast milk, and only a small amount enters the baby’s body through breastfeeding. According to two prospective WHO studies (2466 cases), the micropillar class has no adverse effects on infant growth and development and is therefore suitable for lactating and older women [12]. It is started 6 weeks after delivery or, if not breastfeeding, within 5 days after delivery. It should be noted that the daily dosing time should not be delayed by 3 h. The dosing in the evening will allow the highest level of progesterone and provide better contraceptive effect. If you miss a dose, take 1 tablet immediately, abstain from sex for 48h or add barrier method, and continue to take the next tablet on time.
2.2.3 Developing progestin-only contraceptive method The new progestin norethindrone (ST1435nesterone). This drug has been studied for many years, is rapidly metabolized in the liver, is inactive orally, has no effect on the infant, and is an ideal contraceptive for breastfeeding women [13].ST1435 mono-root type skin burial is effective for 1 year and is suitable for contraceptive needs up to 1 year after delivery.
2.3 Other contraceptive methods
2.3.1 Lactational amenorrhea method The physiological mechanism of thelactationalamenorrhea method (LAM) has not been fully elucidated. It has been shown that ovulation suppression caused by lactation may occur in two ways: first, high prolactin levels cause a lack of responsiveness of the hypothalamic-pituitary axis to hormones secreted by the ovaries, resulting in a decrease in pituitary gonadotropin release and further loss or diminished ovarian viability. Second, the ovaries are in a relatively quiescent state during lactation and are insensitive to gonadotropin stimulation [14]. Many scholars have concluded that lactational amenorrhea is significantly protective during the first 6 months postpartum, with an unwanted pregnancy rate of <2% [15].
2.3.2 Topical contraception The use of topical contraception in breastfeeding women has a minimal likelihood of unintended pregnancy and does not affect the quality or quantity of milk. Condoms also reduce bacterial upstream infections and decrease the incidence of postpartum endometritis. Male and female condoms, jellies, gels, and newer bioadhesive retardants have increased options for postpartum women.
2.3.3 Tubal ligation Tubal ligation in the postpartum period is a simpler and safer procedure because the uterus is larger and finding the fallopian tubes is easy. It does not prolong the hospital stay after surgery and does not increase the risk of postpartum bleeding or infection. Generally, it is appropriate to operate within 72h after delivery, and tubal ligation should be avoided between 8~28d after delivery, as the possibility of infection increases during this period and makes the operation more difficult.
3, the choice of postpartum contraceptive methods and precautions
The choice of postpartum contraceptive methods can be based on the health condition of the mother, the number of births, the type of delivery, whether to breastfeed and the way to breastfeed. Postpartum placement of intrauterine device women, to regular follow-up visits to prevent unintended pregnancy caused by dislodgment. The choice of a breastfeeding amenorrhea contraceptive method is subject to three conditions, i.e., effective for a provisional period of 6 months, amenorrhea, and adherence to breastfeeding. In parallel with this, another contraceptive method should be instructed.
The choice of lactational amenorrhea should meet three conditions: a tentative effective period of 6 months, amenorrhea, and consistent breastfeeding. Change to another method at any time once the baby is supplemented, breastfeeding frequency decreases, or menstruation resumes, otherwise there is a risk of pregnancy. Since estrogen can change the quality and quantity of breast milk, monoprogestin preparations should be chosen for hormonal contraception during postpartum lactation. Lactating women with low estrogen levels, causing reduced vaginal discharge and vaginal dryness, should choose condom gels or jellies. If vaginal films are used, the tablets are not easily dissolved easily leading to contraceptive failure and unintended pregnancy. The new bioadhesive delayed release agents have both barrier effect and spermicidal and lubricating effects, which not only achieve the purpose of contraception, thus also improve the quality of life of postpartum women. Women who request tubal ligation after delivery must pay attention to the following: (1) The decision should be made by the woman herself after fully informed and careful consideration, i.e., only after full consultation and contracting before the procedure to avoid medical disputes.
(2) Ligation should be postponed in case of poor health of the newborn during delivery or maternal complications.
(3) To prevent possible effects of ligation on the lactating mother, local anesthesia is used intraoperatively. In conclusion, postpartum is an important component of women’s health care, and good postpartum contraception can help reduce the rate of unintended pregnancy and protect women’s reproductive health.