Postpartum and early neonatal care

Genital tract

The uterus weighs 1kg after birth but less than 100g by 6 weeks. Uterine muscle fibres undergo autolysis and atrophy, and within 10 days the uterus is no longer palpable abdominally ( Fig. 13.1 ). By the end of the puerperium, the uterus has largely returned to the non-pregnant size. The endometrium regenerates within 6 weeks, and menstruation occurs within this time if lactation has ceased. If lactation continues, the return of menstruation may be deferred for 6 months or more.

Discharge from the uterus is known as lochia . At first this consists of blood, either fresh or altered (lochia rubra), and lasts 2–14 days. It then changes to a serous discharge (lochia serosa) and finally becomes a slight white discharge (lochia alba). These changes may continue for up to 4–8 weeks after delivery. Abnormal persistence of lochia rubra may indicate the presence of retained placental tissue or fetal membranes.

Cardiovascular system

Cardiac output and plasma volume return to normal within approximately 1 week. There is a fluid loss of 2L during the first week and a further loss of 1.5L over the next 5 weeks. This loss is associated with an apparent increase in haematocrit and haemoglobin (Hb) concentration. There is an increase of serum sodium and plasma bicarbonate as well as plasma osmolality. An increase in clotting factors during the first 10 days after delivery is associated with a higher risk of deep vein thrombosis (DVT) and pulmonary embolism. There is also a rise in platelet count and greater platelet adhesiveness. Fibrinogen levels decrease during labour but increase in the puerperium.

Endocrine changes

There are rapid changes in all facets of the endocrine system. There is a rapid fall in the serum levels of oestrogens and progesterone, and they reach non-pregnant levels by the seventh postnatal day. This is associated with an increase in serum prolactin levels in those women who breast-feed. By the tenth postnatal day, human chorionic gonadotrophin (hCG) is no longer detectable.

Colostrum

Colostrum is the first milk and is present in the breast from 12 to 16 weeks of pregnancy. Colostrum is produced for up to 5 days following birth before evolving into transitional milk, from 6 to 13 days, and finally into mature milk from 14 days onwards. It is thick and yellow in colour due to β-carotene and has a mean energy value of 67kcal/dL, compared to 72kcal/dL in mature milk. The volume of colostrum per feed varies from 2 to 20mL in keeping with the size of the newborn’s stomach.

Linked with the importance of the baby having colostrum as its first food is the importance of the baby being skin to skin with its mother after birth. This has the benefit of the baby being colonized by its mother’s bacteria. Colonizing starts during the birth process for vaginally born infants, while those born via caesarean section are more likely to colonize bacteria from the air. Early breast-feeding also promotes tolerance to antigens, thus reducing the number of food allergies in breast-fed babies. The development of healthy intestinal flora also reduces the incidence of allergic disease, inflammatory gut disease and rotavirus diarrhoea in infants.

While breast-feeding is desirable and women should be encouraged, the overall wishes of the woman should not be ignored. There are social and often emotional reasons why a woman may choose not to breast-feed. In some cases, it is not possible or even advisable, such as inverted nipples, previous breast surgery, breast implants, cracked or painful nipples or the mother may have a condition (e.g. HIV) or may be on medical treatment (e.g. chemotherapeutic agents) that serve as a contraindication to breast-feeding.