Labia: The fleshy skin-folds which enclose the clitoris and vaginal orifice.
Lactation: The production of milk in the breasts.
Liquor: see amniotic fluid
Lithotomy position: A position commonly used for vaginal examination, in which the woman lies on her back and her hips and knees are flexed. This allows her pelvis to tilt into a favourable position for examination. It is the opposite of being on "all-fours".
Management: Doctors and midwives may refer to the management of a condition rather than treatment.
Membranes: The bag that encloses the baby and water in the womb. The full name is amniotic membranes.
Membrane rupture: The "breaking of the waters".
Micturition: Passing water or peeing.
Monovular twins: see binovular twins
Moulding: The changes in the shape of the baby's head that occur in the course of labour as it negotiates its way through. It involves the coming together of the skull bones, which may sometimes slightly overlap. Moulding clears up after delivery.
Multiple pregnancy: A pregnancy with more than one fetus.
Obstetrician: A doctor who has specialized in the field of pregnancy and childbirth.
Oligohydramnios: The term used to describe reduced amniotic fluid ("waters") around the baby.
Os: The word means an opening or potential channel. It is used with a prefix;
in this case it may be cervical os.
Ova: The female gametes or "eggs". One "egg" is called an ovum.
Ovulation: The release of ova or "eggs" by the ovaries.
Oxytocin: This is the naturally occurring hormone that stimulates the uterus to contract during labour. There is a synthetic version of the hormone, which is popularly known as Syntocinon or Pitocin. It is the same thing.
Placenta: The afterbirth.
Pelvimetry: This is the measuring of the various parameters of the pelvis. It can be done by vaginal examinations (manual pelvimetry), X-ray or CT scan. It is rarely used in modern obstetrics.
Posterior: see anterior
Postnatal period: The period after delivery. It more or less means the same as the term puerperium.
Pruritus: Itching of the skin.
Puerperium: The period after delivery. It is generally thought to last six weeks.